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Chretien ML, Bailey DG, Asher L, Parfitt J, Driman D, Gregor J, Dresser GK. Severity of coeliac disease and clinical management study when using a non-metabolised medication: a phase I pharmacokinetic study. BMJ Open 2023; 13:e057151. [PMID: 36828648 PMCID: PMC9972437 DOI: 10.1136/bmjopen-2021-057151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 01/27/2023] [Indexed: 02/26/2023] Open
Abstract
OBJECTIVE The non-metabolised antihistamine fexofenadine has oral absorption resulting from transporter activity. Uptake by enterocyte organic anion transporting polypeptides and efflux by an ATP-binding cassette transporter (P-glycoprotein) are primary determinants. Coeliac disease-mediated lesions to the small intestinal mucosa may alter oral absorption of the drug probe, fexofenadine. DESIGN A phase I, open-label, single-dose, pharmacokinetic study SETTING: London, Ontario, Canada PARTICIPANTS: Patients with coeliac disease (n=41) with positive serology and healthy individuals (n=48). MAIN OUTCOME MEASURES Patients with coeliac disease-duodenal histology and oral fexofenadine pharmacokinetics within a 3-week period. Healthy individuals-oral fexofenadine pharmacokinetics with water and grapefruit juice. RESULTS Patients with coeliac disease were stratified by disease severity: Group A (n=15, normal), B+C (n=14, intraepithelial lymphocytosis with/without mild villous blunting) and D (n=12, moderate to severe villous blunting). Patients with coeliac disease in groups A, B+C and D and healthy individuals receiving water had similar fexofenadine AUC0-8 (2038±304, 2259±367, 2128±410, 1954±138 ng.h/mL; p>0.05; mean±SEM) and Cmax (440±73, 513±96, 523±104, 453±32 ng/mL; p>0.05), respectively. These four groups all had higher fexofenadine AUC0-8 (1063±59; p<0.01) and Cmax (253±18; p<0.05) compared with those for healthy individuals receiving grapefruit juice. Coeliac groups had a positive linear trend between disease severity and fexofenadine Tmax (2.0±0.3, 2.7±0.4, 3.1±0.5 hours; p<0.05). CONCLUSIONS Coeliac disease severity based on duodenal histopathology did not affect oral fexofenadine bioavailability. Increased Tmax suggested absorption distal to the duodenum (jejunum + ileum), where histology seems more normal which may be the key determinant. Patients with coeliac disease may not require consideration for alternative clinical drug management for a number of non-metabolised and transport-mediated medications.
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Affiliation(s)
- Marc L Chretien
- Division of Clinical Pharmacology, Department of Medicine, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada
| | - David G Bailey
- Division of Clinical Pharmacology, Department of Medicine, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada
- Lawson Health Research Institute, London, Ontario, Canada
| | - Linda Asher
- Division of Clinical Pharmacology, Department of Medicine, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada
| | - Jeremy Parfitt
- Division of Pathology & Laboratory Medicine, Department of Medicine, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada
| | - David Driman
- Division of Pathology & Laboratory Medicine, Department of Medicine, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada
| | - Jamie Gregor
- Division of Gastroenterology, Department of Medicine, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada
| | - George K Dresser
- Division of Clinical Pharmacology, Department of Medicine, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada
- Lawson Health Research Institute, London, Ontario, Canada
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Chretien ML, Bailey DG, Asher L, Parfitt J, Driman D, Gregor J, Dresser GK. Severity of coeliac disease and clinical management study when using a CYP3A4 metabolised medication: a phase I pharmacokinetic study. BMJ Open 2020; 10:e034086. [PMID: 32139488 PMCID: PMC7059485 DOI: 10.1136/bmjopen-2019-034086] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
OBJECTIVE Severity of coeliac disease depends in part on the extent of small intestinal mucosa injury. Patients with the most abnormal pathology have loss of duodenal villi CYP3A4, a drug-metabolising enzyme that inactivates many drugs. These patients are hypothesised to have greater systemic concentrations of felodipine, a drug which normally has low oral bioavailability secondary to intestinal CYP3A4-mediated metabolism. It serves as a representative for a class containing many medications. DESIGN A phase I, open-label, single-dose, pharmacokinetic study. SETTING London, Ontario, Canada. PARTICIPANTS Patients with coeliac disease (n=47) with positive serology and healthy individuals (n=68). MAIN OUTCOME MEASURES Patients with coeliac disease-upper gastrointestinal endoscopy and oral felodipine pharmacokinetics study within a 3-week period. Healthy individuals-oral felodipine pharmacokinetics study with water and grapefruit juice. RESULTS Coeliac stratification categories: Group A (n=15, normal), B+C (n=16, intraepithelial lymphocytosis with/without mild villous blunting) and D (n=16, moderate/severe villous blunting). Groups A, B+C and D had linear trends of increasing felodipine AUC0-8; mean±SEM, 14.4±2.1, 17.6±2.8, 25.7±5.0; p<0.05) and Cmax (3.5±0.5, 4.0±0.6, 6.4±1.1; p<0.02), respectively. Healthy subjects receiving water had lower felodipine AUC0-8 (11.9±0.9 vs 26.9±0.9, p=0.0001) and Cmax (2.9±0.2 vs 7.7±0.2, p=0.0001) relative to those receiving grapefruit juice. CONCLUSIONS Increased felodipine concentrations in patients with coeliac disease were most probably secondary to decreased small intestinal CYP3A4 expression. Patients with severe coeliac disease and healthy individuals with grapefruit juice had equivalently enhanced effect. Thus, patients with severe coeliac disease would probably experience similarly altered drug response, including overdose toxicity, from many important medications known to be metabolised by CYP3A4. Patients with coeliac disease with severe disease should be considered for other clinical drug management, particularly when there is the potential for serious drug toxicity.
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Affiliation(s)
- Marc L Chretien
- Medicine, London Health Sciences Centre, London, Ontario, Canada
| | - David G Bailey
- Medicine, London Health Sciences Centre, London, Ontario, Canada
- Lawson Health Research Institute, London, Ontario, Canada
| | - Linda Asher
- Medicine, London Health Sciences Centre, London, Ontario, Canada
| | - Jeremy Parfitt
- Pathology and Laboratory Medicine, London Health Sciences Centre, London, Ontario, Canada
| | - David Driman
- Pathology and Laboratory Medicine, London Health Sciences Centre, London, Ontario, Canada
| | - Jamie Gregor
- Medicine, London Health Sciences Centre, London, Ontario, Canada
| | - George K Dresser
- Medicine, London Health Sciences Centre, London, Ontario, Canada
- Lawson Health Research Institute, London, Ontario, Canada
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Dresser GK, Urquhart BL, Freeman DJ, Arnold JMO, Bailey DG. Coffee - Antihypertensive Drug Interaction: A Hemodynamic and Pharmacokinetic Study With Felodipine. J Pharmacol Toxicol Methods 2017. [DOI: 10.1016/j.vascn.2017.09.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Dresser GK, Urquhart BL, Proniuk J, Tieu A, Freeman DJ, Arnold JM, Bailey DG. Coffee inhibition of CYP3A4 in vitro was not translated to a grapefruit-like pharmacokinetic interaction clinically. Pharmacol Res Perspect 2017; 5. [PMID: 28971609 PMCID: PMC5625156 DOI: 10.1002/prp2.346] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Accepted: 07/24/2017] [Indexed: 11/10/2022] Open
Abstract
Grapefruit can augment oral medication bioavailability through irreversible (mechanism‐based) inhibition of intestinal CYP3A4. Supplementary data from our recent coffee–drug interaction clinical study showed some subjects had higher area under the plasma drug concentration ‐ time curve (AUC) and plasma peak drug concentration (Cmax) of the CYP3A4 probe felodipine compared to aqueous control. It was hypothesized that coffee might interact like grapefruit in responsive individuals. Beans from six geographical locations were consistently brewed into coffee that was separated chromatographically to a methanolic fraction for in vitro inhibition testing of CYP3A4 metabolism of felodipine at 1% coffee strength. The effect of simultaneous incubation and 10‐min preincubation with coffee fractions determined whether coffee had direct and mechanism‐based inhibitory activity. A subsequent five‐way randomized balanced controlled crossover clinical study evaluated the clinical pharmacokinetic interaction with single‐dose felodipine. Grapefruit juice, water, or three of the in vitro tested coffees were ingested at 300 mL alone 1 h before and then with felodipine. In vitro, all six coffees decreased felodipine metabolism for both simultaneous and preincubation exposure compared to corresponding control. Five coffees demonstrated mechanism‐based inhibition. Grapefruit increased felodipine AUC0–8 (25 vs. 13 ng.h/mL, P < 0.001) and Cmax (5.8 vs. 2.7 ng/mL, P < 0.001) and decreased dehydrofelodipine/felodipine AUC0–8 ratio (0.84 vs. 1.29, P < 0.001), while the three coffees caused no change in these parameters compared to water. Despite high in vitro potency of CYP3A4 inhibition, the coffees did not cause a clinical pharmacokinetic interaction possibly from insufficient amount of inhibitor(s) in coffee reaching intestinal CYP3A4 during the absorption phase of felodipine. The results of this study highlight the need for follow‐up clinical testing when in vitro results indicate the possibility of an interaction.
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Affiliation(s)
- George K Dresser
- Lawson Health Research Institute, London Health Sciences Centre, Western University, London, Ontario, Canada.,Department of Medicine, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada
| | - Brad L Urquhart
- Department of Physiology & Pharmacology, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada
| | - Julianne Proniuk
- Department of Physiology & Pharmacology, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada
| | - Alvin Tieu
- Department of Physiology & Pharmacology, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada
| | - David J Freeman
- Department of Medicine, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada.,Department of Physiology & Pharmacology, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada
| | - John Malcolm Arnold
- Department of Medicine, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada
| | - David G Bailey
- Lawson Health Research Institute, London Health Sciences Centre, Western University, London, Ontario, Canada.,Department of Medicine, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada
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Bailey DG, Dresser GK, Urquhart BL, Freeman DJ, Arnold JM. Coffee-Antihypertensive Drug Interaction: A Hemodynamic and Pharmacokinetic Study With Felodipine. Am J Hypertens 2016; 29:1386-1393. [PMID: 27481881 DOI: 10.1093/ajh/hpw081] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Accepted: 07/12/2016] [Indexed: 11/12/2022] Open
Abstract
OBJECTIVES A period of abstinence from coffee to permit caffeine elimination appears to enable increased blood pressure on subsequent exposure. We hypothesized that this would offset the antihypertensive effect of the dihydropyridine calcium channel blocker felodipine. METHODS A randomized, single-dose, crossover study assessed hemodynamic and pharmacokinetic effects following 2 days without coffee and caffeine-containing foods. Consistently brewed black coffee (2×300ml), felodipine maximum recommended dose (10mg), and coffee plus felodipine were tested in middle-aged normotensive subjects. RESULTS Pretreatment plasma caffeine concentrations were unquantifiable. After coffee, blood pressure changes (mm Hg) averaged over study hours 1-4 were increased for brachial systolic (7.6, P < 0.001) and diastolic (4.9, P < 0.001) and aortic systolic (7.4, P < 0.001), pulse (3.0, P < 0.05) and augmentation (1.4, P < 0.05) relative to baseline. After coffee plus felodipine, they were higher for brachial systolic (4.0, P < 0.05) and diastolic (3.9, P < 0.001) and aortic systolic (4.6, P < 0.05) compared to felodipine alone. The pressor effects of coffee and its modulation by felodipine were variable among individuals. Coffee containing caffeine (127mg) caused maximum pressor effect. Caffeine and felodipine pharmacokinetics were similar for coffee and felodipine given alone or in combination indicating an interaction having a pharmacodynamic basis. Plasma felodipine concentration-diastolic blood pressure reduction relationship shifted with coffee such that doubling the felodipine concentration would eliminate the pressor effect. However, this may increase the risk of adverse drug events particularly during the timeframe without coffee. CONCLUSION Intermittent coffee ingestion might complicate hypertension diagnosis and management for many individuals.
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Affiliation(s)
- David G Bailey
- Lawson Health Research Institute, London Health Sciences Centre, Western University, London, Ontario, Canada
- Department of Medicine, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - George K Dresser
- Lawson Health Research Institute, London Health Sciences Centre, Western University, London, Ontario, Canada
- Department of Medicine, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | | | - David J Freeman
- Department of Medicine, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - John Malcolm Arnold
- Department of Medicine, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
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Affiliation(s)
- David G Bailey
- Lawson Health Research Institute and Department of Medicine, Schulich School of Medicine & Dentistry, Western University, London, Ont, Canada
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Bailey DG. Predicting clinical relevance of grapefruit-drug interactions: a complicated process. J Clin Pharm Ther 2016; 42:125-127. [PMID: 27709656 DOI: 10.1111/jcpt.12463] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Accepted: 09/07/2016] [Indexed: 12/01/2022]
Abstract
WHAT IS KNOWN AND OBJECTIVE Grapefruit juice interacts with a number of drugs. This commentary provides feedback on a previously proposed approach for predicting clinically relevant interactions with grapefruit juice based on the average inherent oral bioavailability (F) and magnitude of increase in bioavailability with other CYP3A inhibitors of the drug. COMMENT Additional factors such as variability of the magnitude of the pharmacokinetic interaction among individuals, product monograph cautionary statements and vulnerability of the patient population should be considered. WHAT IS NEW AND CONCLUSION A flow diagram is provided that should improve prediction of the pharmacokinetic interaction and clinical relevance for affected drugs and that recommends different courses of action for patient management. Forecasting the clinical importance of a particular drug interaction with grapefruit can be improved through consideration of additional readily available drug regulatory information.
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Affiliation(s)
- D G Bailey
- Lawson Health Research Institute and Department of Medicine, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada
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Li DQ, Kim R, McArthur E, Fleet JL, Bailey DG, Juurlink D, Shariff SZ, Gomes T, Mamdani M, Gandhi S, Dixon S, Garg AX. Risk of adverse events among older adults following co-prescription of clarithromycin and statins not metabolized by cytochrome P450 3A4. CMAJ 2014; 187:174-180. [PMID: 25534598 DOI: 10.1503/cmaj.140950] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND The cytochrome P450 3A4 (CYP3A4) inhibitor clarithromycin may also inhibit liver-specific organic anion-transporting polypeptides (OATP1B1 and OATP1B3). We studied whether concurrent use of clarithromycin and a statin not metabolized by CYP3A4 was associated with an increased frequency of serious adverse events. METHODS Using large health care databases, we studied a population-based cohort of older adults (mean age 74 years) who were taking a statin not metabolized by CYP3A4 (rosuvastatin [76% of prescriptions], pravastatin [21%] or fluvastatin [3%]) between 2002 and 2013 and were newly prescribed clarithromycin (n=51,523) or azithromycin (n=52,518), the latter an antibiotic that inhibits neither CYP3A4 nor OATP1B1 and OATP1B3. Outcomes were hospital admission with a diagnostic code for rhabdomyolysis, acute kidney injury or hyperkalemia, and all-cause mortality. All outcomes were assessed within 30 days after co-prescription. RESULTS Compared with the control group, patients co-prescribed clarithromycin and a statin not metabolized by CYP3A4 were at increased risk of hospital admission with acute kidney injury (adjusted relative risk [RR] 1.65, 95% confidence interval [CI] 1.31 to 2.09), admission with hyperkalemia (adjusted RR 2.17, 95% CI 1.22 to 3.86) and all-cause mortality (adjusted RR 1.43, 95% CI 1.15 to 1.76). The adjusted RR for admission with rhabdomyolysis was 2.27 (95% CI 0.86 to 5.96). The absolute increase in risk for each outcome was small and likely below 1%, even after we considered the insensitivity of some hospital database codes. INTERPRETATION Among older adults taking a statin not metabolized by CYP3A4, co-prescription of clarithromycin versus azithromycin was associated with a modest but statistically significant increase in the 30-day absolute risk of adverse outcomes.
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Affiliation(s)
- Daniel Q Li
- Divisions of Nephrology (Li, McArthur, Fleet, Shariff, Gandhi, Dixon, Garg) and Clinical Pharmacology (Kim), Department of Medicine, Western University, London, Ont.; Institute for Clinical Evaluative Sciences (ICES) Western (McArthur, Juurlink, Shariff, Gomes, Dixon, Garg), London, Ont.; Lawson Health Research Institute (Bailey), London Health Sciences Centre, London, Ont.; Sunnybrook Health Sciences Centre (Juurlink), Toronto, Ont.; Li Ka Shing Knowledge Institute (Gomes, Mamdani), St. Michael's Hospital, Toronto, Ont.; Institute of Health Policy, Management and Evaluation (Mamdani), University of Toronto, Toronto, Ont.; Department of Epidemiology and Biostatistics (Gandhi), Western University, London, Ont
| | - Richard Kim
- Divisions of Nephrology (Li, McArthur, Fleet, Shariff, Gandhi, Dixon, Garg) and Clinical Pharmacology (Kim), Department of Medicine, Western University, London, Ont.; Institute for Clinical Evaluative Sciences (ICES) Western (McArthur, Juurlink, Shariff, Gomes, Dixon, Garg), London, Ont.; Lawson Health Research Institute (Bailey), London Health Sciences Centre, London, Ont.; Sunnybrook Health Sciences Centre (Juurlink), Toronto, Ont.; Li Ka Shing Knowledge Institute (Gomes, Mamdani), St. Michael's Hospital, Toronto, Ont.; Institute of Health Policy, Management and Evaluation (Mamdani), University of Toronto, Toronto, Ont.; Department of Epidemiology and Biostatistics (Gandhi), Western University, London, Ont
| | - Eric McArthur
- Divisions of Nephrology (Li, McArthur, Fleet, Shariff, Gandhi, Dixon, Garg) and Clinical Pharmacology (Kim), Department of Medicine, Western University, London, Ont.; Institute for Clinical Evaluative Sciences (ICES) Western (McArthur, Juurlink, Shariff, Gomes, Dixon, Garg), London, Ont.; Lawson Health Research Institute (Bailey), London Health Sciences Centre, London, Ont.; Sunnybrook Health Sciences Centre (Juurlink), Toronto, Ont.; Li Ka Shing Knowledge Institute (Gomes, Mamdani), St. Michael's Hospital, Toronto, Ont.; Institute of Health Policy, Management and Evaluation (Mamdani), University of Toronto, Toronto, Ont.; Department of Epidemiology and Biostatistics (Gandhi), Western University, London, Ont
| | - Jamie L Fleet
- Divisions of Nephrology (Li, McArthur, Fleet, Shariff, Gandhi, Dixon, Garg) and Clinical Pharmacology (Kim), Department of Medicine, Western University, London, Ont.; Institute for Clinical Evaluative Sciences (ICES) Western (McArthur, Juurlink, Shariff, Gomes, Dixon, Garg), London, Ont.; Lawson Health Research Institute (Bailey), London Health Sciences Centre, London, Ont.; Sunnybrook Health Sciences Centre (Juurlink), Toronto, Ont.; Li Ka Shing Knowledge Institute (Gomes, Mamdani), St. Michael's Hospital, Toronto, Ont.; Institute of Health Policy, Management and Evaluation (Mamdani), University of Toronto, Toronto, Ont.; Department of Epidemiology and Biostatistics (Gandhi), Western University, London, Ont
| | - David G Bailey
- Divisions of Nephrology (Li, McArthur, Fleet, Shariff, Gandhi, Dixon, Garg) and Clinical Pharmacology (Kim), Department of Medicine, Western University, London, Ont.; Institute for Clinical Evaluative Sciences (ICES) Western (McArthur, Juurlink, Shariff, Gomes, Dixon, Garg), London, Ont.; Lawson Health Research Institute (Bailey), London Health Sciences Centre, London, Ont.; Sunnybrook Health Sciences Centre (Juurlink), Toronto, Ont.; Li Ka Shing Knowledge Institute (Gomes, Mamdani), St. Michael's Hospital, Toronto, Ont.; Institute of Health Policy, Management and Evaluation (Mamdani), University of Toronto, Toronto, Ont.; Department of Epidemiology and Biostatistics (Gandhi), Western University, London, Ont
| | - David Juurlink
- Divisions of Nephrology (Li, McArthur, Fleet, Shariff, Gandhi, Dixon, Garg) and Clinical Pharmacology (Kim), Department of Medicine, Western University, London, Ont.; Institute for Clinical Evaluative Sciences (ICES) Western (McArthur, Juurlink, Shariff, Gomes, Dixon, Garg), London, Ont.; Lawson Health Research Institute (Bailey), London Health Sciences Centre, London, Ont.; Sunnybrook Health Sciences Centre (Juurlink), Toronto, Ont.; Li Ka Shing Knowledge Institute (Gomes, Mamdani), St. Michael's Hospital, Toronto, Ont.; Institute of Health Policy, Management and Evaluation (Mamdani), University of Toronto, Toronto, Ont.; Department of Epidemiology and Biostatistics (Gandhi), Western University, London, Ont
| | - Salimah Z Shariff
- Divisions of Nephrology (Li, McArthur, Fleet, Shariff, Gandhi, Dixon, Garg) and Clinical Pharmacology (Kim), Department of Medicine, Western University, London, Ont.; Institute for Clinical Evaluative Sciences (ICES) Western (McArthur, Juurlink, Shariff, Gomes, Dixon, Garg), London, Ont.; Lawson Health Research Institute (Bailey), London Health Sciences Centre, London, Ont.; Sunnybrook Health Sciences Centre (Juurlink), Toronto, Ont.; Li Ka Shing Knowledge Institute (Gomes, Mamdani), St. Michael's Hospital, Toronto, Ont.; Institute of Health Policy, Management and Evaluation (Mamdani), University of Toronto, Toronto, Ont.; Department of Epidemiology and Biostatistics (Gandhi), Western University, London, Ont
| | - Tara Gomes
- Divisions of Nephrology (Li, McArthur, Fleet, Shariff, Gandhi, Dixon, Garg) and Clinical Pharmacology (Kim), Department of Medicine, Western University, London, Ont.; Institute for Clinical Evaluative Sciences (ICES) Western (McArthur, Juurlink, Shariff, Gomes, Dixon, Garg), London, Ont.; Lawson Health Research Institute (Bailey), London Health Sciences Centre, London, Ont.; Sunnybrook Health Sciences Centre (Juurlink), Toronto, Ont.; Li Ka Shing Knowledge Institute (Gomes, Mamdani), St. Michael's Hospital, Toronto, Ont.; Institute of Health Policy, Management and Evaluation (Mamdani), University of Toronto, Toronto, Ont.; Department of Epidemiology and Biostatistics (Gandhi), Western University, London, Ont
| | - Muhammad Mamdani
- Divisions of Nephrology (Li, McArthur, Fleet, Shariff, Gandhi, Dixon, Garg) and Clinical Pharmacology (Kim), Department of Medicine, Western University, London, Ont.; Institute for Clinical Evaluative Sciences (ICES) Western (McArthur, Juurlink, Shariff, Gomes, Dixon, Garg), London, Ont.; Lawson Health Research Institute (Bailey), London Health Sciences Centre, London, Ont.; Sunnybrook Health Sciences Centre (Juurlink), Toronto, Ont.; Li Ka Shing Knowledge Institute (Gomes, Mamdani), St. Michael's Hospital, Toronto, Ont.; Institute of Health Policy, Management and Evaluation (Mamdani), University of Toronto, Toronto, Ont.; Department of Epidemiology and Biostatistics (Gandhi), Western University, London, Ont
| | - Sonja Gandhi
- Divisions of Nephrology (Li, McArthur, Fleet, Shariff, Gandhi, Dixon, Garg) and Clinical Pharmacology (Kim), Department of Medicine, Western University, London, Ont.; Institute for Clinical Evaluative Sciences (ICES) Western (McArthur, Juurlink, Shariff, Gomes, Dixon, Garg), London, Ont.; Lawson Health Research Institute (Bailey), London Health Sciences Centre, London, Ont.; Sunnybrook Health Sciences Centre (Juurlink), Toronto, Ont.; Li Ka Shing Knowledge Institute (Gomes, Mamdani), St. Michael's Hospital, Toronto, Ont.; Institute of Health Policy, Management and Evaluation (Mamdani), University of Toronto, Toronto, Ont.; Department of Epidemiology and Biostatistics (Gandhi), Western University, London, Ont
| | - Stephanie Dixon
- Divisions of Nephrology (Li, McArthur, Fleet, Shariff, Gandhi, Dixon, Garg) and Clinical Pharmacology (Kim), Department of Medicine, Western University, London, Ont.; Institute for Clinical Evaluative Sciences (ICES) Western (McArthur, Juurlink, Shariff, Gomes, Dixon, Garg), London, Ont.; Lawson Health Research Institute (Bailey), London Health Sciences Centre, London, Ont.; Sunnybrook Health Sciences Centre (Juurlink), Toronto, Ont.; Li Ka Shing Knowledge Institute (Gomes, Mamdani), St. Michael's Hospital, Toronto, Ont.; Institute of Health Policy, Management and Evaluation (Mamdani), University of Toronto, Toronto, Ont.; Department of Epidemiology and Biostatistics (Gandhi), Western University, London, Ont
| | - Amit X Garg
- Divisions of Nephrology (Li, McArthur, Fleet, Shariff, Gandhi, Dixon, Garg) and Clinical Pharmacology (Kim), Department of Medicine, Western University, London, Ont.; Institute for Clinical Evaluative Sciences (ICES) Western (McArthur, Juurlink, Shariff, Gomes, Dixon, Garg), London, Ont.; Lawson Health Research Institute (Bailey), London Health Sciences Centre, London, Ont.; Sunnybrook Health Sciences Centre (Juurlink), Toronto, Ont.; Li Ka Shing Knowledge Institute (Gomes, Mamdani), St. Michael's Hospital, Toronto, Ont.; Institute of Health Policy, Management and Evaluation (Mamdani), University of Toronto, Toronto, Ont.; Department of Epidemiology and Biostatistics (Gandhi), Western University, London, Ont.
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Abstract
IMPORTANCE Calcium-channel blockers are metabolized by the cytochrome P450 3A4 (CYP3A4; EC 1.14.13.97) enzyme. Blood concentrations of these drugs may rise to harmful levels when CYP3A4 activity is inhibited. Clarithromycin is an inhibitor of CYP3A4 and azithromycin is not, which makes comparisons between these 2 macrolide antibiotics useful in assessing clinically important drug interactions. OBJECTIVE To characterize the risk of acute adverse events following coprescription of clarithromycin compared with azithromycin in older adults taking a calcium-channel blocker. DESIGN, SETTING, AND PARTICIPANTS Population-based retrospective cohort study in Ontario, Canada, from 2003 through 2012 of older adults (mean age, 76 years) who were newly coprescribed clarithromycin (n = 96,226) or azithromycin (n = 94,083) while taking a calcium-channel blocker (amlodipine, felodipine, nifedipine, diltiazem, or verapamil). MAIN OUTCOMES AND MEASURES Hospitalization with acute kidney injury (primary outcome) and hospitalization with hypotension and all-cause mortality (secondary outcomes examined separately). Outcomes were assessed within 30 days of a new coprescription. RESULTS There were no differences in measured baseline characteristics between the clarithromycin and azithromycin groups. Amlodipine was the most commonly prescribed calcium-channel blocker (more than 50% of patients). Coprescribing clarithromycin vs azithromycin with a calcium-channel blocker was associated with a higher risk of hospitalization with acute kidney injury (420 patients of 96,226 taking clarithromycin [0.44%] vs 208 patients of 94,083 taking azithromycin [0.22%]; absolute risk increase, 0.22% [95% CI, 0.16%-0.27%]; odds ratio [OR], 1.98 [95% CI, 1.68-2.34]). In a subgroup analysis, the risk was highest with dihydropyridines, particularly nifedipine (OR, 5.33 [95% CI, 3.39-8.38]; absolute risk increase, 0.63% [95% CI, 0.49%-0.78%]). Coprescription with clarithromycin was also associated with a higher risk of hospitalization with hypotension (111 patients of 96,226 taking clarithromycin [0.12%] vs 68 patients of 94,083 taking azithromycin [0.07%]; absolute risk increase, 0.04% [95% CI, 0.02%-0.07%]; OR, 1.60 [95% CI, 1.18-2.16]) and all-cause mortality (984 patients of 96,226 taking clarithromycin [1.02%] vs 555 patients of 94,083 taking azithromycin [0.59%]; absolute risk increase, 0.43% [95% CI, 0.35%-0.51%]; OR, 1.74 [95% CI, 1.57-1.93]). CONCLUSIONS AND RELEVANCE Among older adults taking a calcium-channel blocker, concurrent use of clarithromycin compared with azithromycin was associated with a small but statistically significant greater 30-day risk of hospitalization with acute kidney injury. These findings support current safety warnings regarding concurrent use of CYP3A4 inhibitors and calcium-channel blockers.
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Affiliation(s)
- Sonja Gandhi
- Division of Nephrology, Department of Medicine, Western University, London, Canada2Department of Epidemiology and Biostatistics, Western University, London, Canada
| | - Jamie L Fleet
- Division of Nephrology, Department of Medicine, Western University, London, Canada
| | - David G Bailey
- Lawson Health Research Institute, London Health Sciences Centre, London, Canada
| | - Eric McArthur
- Division of Nephrology, Department of Medicine, Western University, London, Canada4Institute for Clinical Evaluative Sciences, Ontario, Canada
| | - Ron Wald
- Division of Nephrology, Department of Medicine, St Michael's Hospital and University of Toronto, Toronto, Canada
| | - Faisal Rehman
- Division of Nephrology, Department of Medicine, Western University, London, Canada
| | - Amit X Garg
- Division of Nephrology, Department of Medicine, Western University, London, Canada2Department of Epidemiology and Biostatistics, Western University, London, Canada3Lawson Health Research Institute, London Health Sciences Centre, London, Canada4Institute for Clinical Evaluative Sciences, Ontario, Canada
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Bailey DG. Grapefruit juice and clopidogrel. CMAJ 2013; 185:1066. [DOI: 10.1503/cmaj.113-2127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
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Patel AM, Shariff S, Bailey DG, Juurlink DN, Gandhi S, Mamdani M, Gomes T, Fleet J, Hwang YJ, Garg AX. Statin toxicity from macrolide antibiotic coprescription: a population-based cohort study. Ann Intern Med 2013; 158:869-76. [PMID: 23778904 DOI: 10.7326/0003-4819-158-12-201306180-00004] [Citation(s) in RCA: 104] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND Clarithromycin and erythromycin, but not azithromycin, inhibit cytochrome P450 isoenzyme 3A4 (CYP3A4), and inhibition increases blood concentrations of statins that are metabolized by CYP3A4. OBJECTIVE To measure the frequency of statin toxicity after coprescription of a statin with clarithromycin or erythromycin. DESIGN Population-based cohort study. SETTING Ontario, Canada, from 2003 to 2010. PATIENTS Continuous statin users older than 65 years who were prescribed clarithromycin (n = 72,591) or erythromycin (n = 3267) compared with those prescribed azithromycin (n = 68,478). MEASUREMENTS The primary outcome was hospitalization with rhabdomyolysis within 30 days of the antibiotic prescription. RESULTS Atorvastatin was the most commonly prescribed statin (73%) followed by simvastatin and lovastatin. Compared with azithromycin, coprescription of a statin with clarithromycin or erythromycin was associated with a higher risk for hospitalization with rhabdomyolysis (absolute risk increase, 0.02% [95% CI, 0.01% to 0.03%]; relative risk [RR], 2.17 [CI, 1.04 to 4.53]) or with acute kidney injury (absolute risk increase, 1.26% [CI, 0.58% to 1.95%]; RR, 1.78 [CI, 1.49 to 2.14]) and for all-cause mortality (absolute risk increase, 0.25% [CI, 0.17% to 0.33%]; RR, 1.56 [CI, 1.36 to 1.80]). LIMITATIONS Only older adults were included in the study. The absolute risk increase for rhabdomyolysis may be underestimated because the codes used to identify it were insensitive. CONCLUSION In older adults, coprescription of clarithromycin or erythromycin with a statin that is metabolized by CYP3A4 increases the risk for statin toxicity. PRIMARY FUNDING SOURCE Academic Medical Organization of Southwestern Ontario.
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Affiliation(s)
- Amit M Patel
- Western University and Lawson Health Research Institute, London Health Sciences Centre, London, Ontario, Canada
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Fleet JL, Shariff SZ, Bailey DG, Gandhi S, Juurlink DN, Nash DM, Mamdani M, Gomes T, Patel AM, Garg AX. Comparing two types of macrolide antibiotics for the purpose of assessing population-based drug interactions. BMJ Open 2013; 3:bmjopen-2013-002857. [PMID: 23847265 PMCID: PMC3710981 DOI: 10.1136/bmjopen-2013-002857] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
OBJECTIVE Clarithromycin strongly inhibits enzyme cytochrome P450 3A4, preventing the metabolism of some other drugs, while azithromycin is a weak inhibitor. Accordingly, blood concentrations of other drugs increase with clarithromycin coprescription leading to adverse events. These macrolide antibiotics also differ on other properties that may impact outcomes. In this study, we compared outcomes in two groups of macrolide antibiotic users in the absence of potentially interacting drugs. DESIGN Population-based retrospective cohort study. SETTING Ontario, Canada, from 2003 to 2010. PATIENTS Patients (mean 74 years) prescribed clarithromycin (n=52 251) or azithromycin (referent group, n=46 618). MAIN OUTCOMES The primary outcomes were hospital admission within 30 days of a new antibiotic prescription with any of the 12 conditions examined separately (acute kidney injury, acute myocardial infarction, neuroimaging (proxy for delirium), hypotension, syncope, hyperkalaemia, hyponatraemia, hyperglycaemia, arrhythmia, ischaemic stroke, gastrointestinal bleeding and sepsis). The secondary outcome was mortality. RESULTS The baseline characteristics of the two groups, including patient demographics, comorbid conditions, infection type and prescribing physician specialty, were nearly identical. The median daily dose was 1000 mg for clarithromycin and 300 mg for azithromycin and the median duration of dispensing antibiotics was 10 and 5 days, respectively. There was no difference between the groups in the risk of hospitalisation for any condition studied (relative risk ranged from 0.67 to 1.23). Compared with azithromycin, clarithromycin was associated with a slightly higher risk of all-cause mortality (0.46% vs 0.37%, relative risk 1.25, 95% CI 1.03 to 1.52). CONCLUSIONS Clarithromycin can be used to assess drug interactions in population-based studies with azithromycin serving as a control group. However, any differences in mortality observed between the two antibiotic groups in the setting of other drug use may be partially attributable to factors beyond the inhibition of drug metabolising enzymes and transporters, as the difference for this outcome was significant.
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Affiliation(s)
- Jamie L Fleet
- Division of Nephrology, Department of Medicine, Western University, London, Canada
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Abstract
A new type of interaction in which fruit juices diminish oral drug bioavailability through inhibition of uptake transport is the focus of this review. The discovery was based on an opposite to anticipated finding when assessing the possibility of grapefruit juice increasing oral fexofenadine bioavailability in humans through inhibition of intestinal MDR1-mediated efflux transport. In follow-up investigations, grapefruit or orange juice at low concentrations potentially and selectively inhibited in vitro OATP1A2-mediated uptake compared with MDR1-caused efflux substrate transport. These juices at high volume dramatically depressed oral fexofenadine bioavailability. Grapefruit was the representative juice to characterize the interaction subsequently. A volume-effect relationship study using a normal juice amount halved average fexofenadine absorption. Individual variability and reproducibility data indicated the clinical interaction involved direct inhibition of intestinal OATP1A2. Naringin was a major causal component suggesting that other flavonoids in fruits and vegetables might also produce the effect. Duration of juice clinical inhibition of fexofenadine absorption lasted more than 2 h but less than 4 h indicating the interaction was avoidable with appropriate interval of time between juice and drug consumption. Grapefruit juice lowered the oral bioavailability of several medications transported by OATP1A2 (acebutolol, celiprolol, fexofenadine, talinolol, L-thyroxine) while orange juice did the same for others (atenolol, celiprolol, ciprofloxacin, fexofenadine). Juice clinical inhibition of OATP2B1 was unresolved while that of OATP1B1 seemed unlikely. The interaction between grapefruit juice and etoposide also seemed relevant. Knowledge of both affected uptake transporter and drug hydrophilicity assisted prediction of the clinical interaction with grapefruit or orange juice.
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Affiliation(s)
- David G Bailey
- Department of Medicine and Lawson Health Research Institute, London Health Sciences Centre Department of Physiology & Pharmacology, University of Western Ontario, London, Ontario, Canada.
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Asanuma Y, Oeser A, Stanley E, Bailey DG, Shintani A, Stein CM. Effects of C-reactive Protein and Homocysteine on Cytokine Production: Modulation by Pravastatin. ACTA ACUST UNITED AC 2008; 1:14-22. [PMID: 20157364 PMCID: PMC2817441 DOI: 10.1111/j.1753-5174.2007.00003.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVE: C-reactive protein (CRP) and homocysteine are markers of cardiovascular risk that may have inflammatory effects. HMG coenzyme A reductase inhibitors (statins) have anti-inflammatory effects in vitro, but it is not clear if such responses in vivo are secondary to lipid lowering. We examined the hypothesis that CRP and homocysteine would stimulate cytokine release in human whole blood and that short-term treatment with a statin would inhibit it. METHODS: The time course of IL-6 and MCP-1 production was determined in whole blood incubated with saline, 1 microg/mL lipopolysaccaride (LPS), 50 and 100 microM/L DL-homocysteine, and 5 microg/mL human recombinant CRP for 24 hours at 37 degrees C under 5% CO(2) atmosphere. Cytokine responses were determined in blood drawn from 15 healthy volunteers before and after administration of pravastatin 40 mg daily for 2 days. RESULTS: Both human recombinant CRP and LPS significantly increased the production of IL-6 and MCP-1 in whole blood samples more than 4-fold (P < 0.001) but homocysteine did not. Oral administration of pravastatin, 40mg daily for 2 days, decreased CRP-stimulated IL-6 production by approximately 20% (P = 0.02) 6 hours after incubation, but did not affect MCP-1 production (P = 0.69). Pravastatin treatment did not affect LPS-stimulated MCP-1 but increased IL-6 modestly. CONCLUSIONS: CRP stimulated the production of the proatherogenic mediators MCP-1 and IL-6 in human whole blood, but homocysteine did not. CRP-stimulated production of IL-6, but not MCP-1, was modestly attenuated by short-term treatment with pravastatin.
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Affiliation(s)
- Yu Asanuma
- Division of Rheumatology and Applied Immunology, Saitama Medical UniversitySaitama, Japan
- Division of Clinical Pharmacology, Vanderbilt University School of MedicineNashville, TN, USA
| | - Annette Oeser
- Division of Clinical Pharmacology, Vanderbilt University School of MedicineNashville, TN, USA
| | - Eran Stanley
- Division of Clinical Pharmacology, Vanderbilt University School of MedicineNashville, TN, USA
| | - David G Bailey
- Department of Medicine, Lawson Health Research Institute Health Sciences Centre LondonOntario, Canada
| | - Ayumi Shintani
- Division of General Internal Medicine, Vanderbilt University School of MedicineNashville, TN, USA
| | - C Michael Stein
- Division of Clinical Pharmacology, Vanderbilt University School of MedicineNashville, TN, USA
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Ho RH, Choi L, Lee W, Mayo G, Schwarz UI, Tirona RG, Bailey DG, Stein CM, Kim RB. Effect of drug transporter genotypes on pravastatin disposition in European- and African-American participants. Pharmacogenet Genomics 2007; 17:647-56. [PMID: 17622941 PMCID: PMC4063287 DOI: 10.1097/fpc.0b013e3280ef698f] [Citation(s) in RCA: 140] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE Our aims were to evaluate the effects of polymorphisms in the hepatic drug uptake transporter organic anion transporting polypeptide 1B1 (OATP1B1, SLCO1B1) and efflux transporters multidrug resistance-associated protein 2 (MRP2, ABCC2), bile salt export pump (BSEP, ABCB11), and breast cancer-related protein (BCRP, ABCG2) on single-dose pravastatin pharmacokinetics in healthy European- and African-American participants. METHODS The pharmacokinetics of a single oral 40 mg dose of pravastatin was determined in 107 participants (69 European-Americans and 38 African-Americans). Participants were genotyped for known OATP1B1, MRP2, BSEP, and BCRP polymorphisms. Baseline serum total and unconjugated plasma bilirubin concentrations were also determined. RESULTS OATP1B1 genotypes were ethnicity-dependent with a 521C allele frequency of approximately 15% in European-Americans and approximately 1% in African-Americans. SLCO1B1 521TC genotype was associated with significantly higher pravastatin area under the curve [AUC(0-5)] (P=0.01) and Cmax values (P<0.05). When analyzed by diplotype, SLCO1B1*1a/*15 (N=8) participants exhibited 45 and 80% higher AUC values than SLCO1B1*1a/*1a (N=29) (P=0.013) and SLCO1B1*1b/*1b (N=34) (P=0.001) carriers, respectively. SLCO1B1*15/*15 (N=2) participants exhibited 92 and 149% higher AUC values than SLCO1B1*1a/*1a (P=0.017) and SLCO1B1*1b/*1b (P=0.011) carriers, respectively. European-Americans had significantly higher plasma pravastatin AUC(0-5) (P=0.01) and Cmax values (P=0.009) than African-Americans. Neither ABCC2, ABCB11, nor ABCG2 genotypes were associated with differences in pravastatin pharmacokinetics. We did not observe an effect of SLCO1B1 genotype on baseline total or unconjugated bilirubin levels. CONCLUSION SLCO1B1 genotype, in particular the 521C allele, had a significant effect on the pharmacokinetics of pravastatin. Even when adjusted for the presence of the SLCO1B1 521C or 388G variant allele, European-Americans demonstrated significantly higher pravastatin AUC and Cmax values than African-Americans.
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Affiliation(s)
- Richard H. Ho
- Department of Pediatrics and Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Leena Choi
- Department of Biostatistics, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Wooin Lee
- Division of Clinical Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Gail Mayo
- Division of Clinical Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Ute I. Schwarz
- Division of Clinical Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
- Division of Clinical Pharmacology, Department of Medicine, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
| | - Rommel G. Tirona
- Division of Clinical Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
- Division of Clinical Pharmacology, Department of Medicine, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
| | - David G. Bailey
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
- Division of Clinical Pharmacology, Department of Medicine, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
| | - C. Michael Stein
- Division of Clinical Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Richard B. Kim
- Division of Clinical Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
- Division of Clinical Pharmacology, Department of Medicine, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
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Schwarz UI, Johnston PE, Bailey DG, Kim RB, Mayo G, Milstone A. Impact of citrus soft drinks relative to grapefruit juice on ciclosporin disposition. Br J Clin Pharmacol 2007; 62:485-91. [PMID: 16995870 PMCID: PMC1885147 DOI: 10.1111/j.1365-2125.2005.02519.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
AIMS A recent case report had suggested a citrus soft drink (Sun Drop) may have caused clinically relevant elevations in ciclosporin levels through a grapefruit juice-like mechanism via inactivation of intestinal cytochrome P450 3A4 (CYP3A4). This study was conducted to investigate the effect of grapefruit juice and citrus sodas Sun Drop and Fresca, the latter soda containing 83-fold higher concentration of the proposed CYP3A4 inhibitor bergamottin than Sun Drop, relative to water on oral ciclosporin pharmacokinetics. METHODS In a randomized four-way crossover study with a washout of at least 1 week, 12 healthy volunteers received a single oral dose of ciclosporin (Neoral) with Sun Drop, Fresca, grapefruit juice and water (control). Each drink (591 ml) was consumed twice on the prior day and three times on the study day. Whole blood concentrations of ciclosporin were measured up to 24 h with a fluorescence polarization immunoassay. RESULTS Grapefruit juice increased area under the concentration-time curve by 186% (P < 0.0001; 95% confidence interval of mean difference 3302-6240 ng ml h(-1)) and peak concentration by 150% (P < 0.0001) of ciclosporin with a significant decrease in oral clearance of 43% (P < 0.0001) when compared with water. Neither citrus soda altered significantly ciclosporin pharmacokinetic variables; changes in mean values ranged from +/- 3 to 11% of the corresponding water value. CONCLUSION Although our results do not support a clinically relevant grapefruit juice-like interaction between oral ciclosporin and citrus constituent containing sodas Sun Drop or Fresca, an effect in the setting of chronic ciclosporin therapy cannot be ruled out.
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Affiliation(s)
- Ute I Schwarz
- Pharmaceutical Services, Vanderbilt University Medical Center, Nashville, TN 37232, USA.
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Bailey DG, Dresser GK, Leake BF, Kim RB. Naringin is a major and selective clinical inhibitor of organic anion-transporting polypeptide 1A2 (OATP1A2) in grapefruit juice. Clin Pharmacol Ther 2007; 81:495-502. [PMID: 17301733 DOI: 10.1038/sj.clpt.6100104] [Citation(s) in RCA: 187] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We showed previously that grapefruit and orange juices inhibited human enteric organic anion-transporting polypeptide (OATP)1A2 in vitro and lowered oral fexofenadine bioavailability clinically. Inhibition of OATP1A2 transport by flavonoids in grapefruit (naringin) and orange (hesperidin) was conducted in vitro. Two randomized, crossover, pharmacokinetic studies were performed clinically. In one study, 120 mg of fexofenadine was ingested with 300 ml grapefruit juice, an aqueous solution of naringin at the same juice concentration (1,200 microM), or water. In the other study, fexofenadine was administered with grapefruit juice, with or 2 h before aqueous suspension of the particulate fraction of juice containing known clinical inhibitors of enteric CYP3A4, but relatively low naringin concentration (34 microM), or with water. Naringin and hesperidin's half-maximal inhibitions were 3.6 and 2.7 microM, respectively. Fexofenadine area under the plasma drug concentration-time curves (AUCs) with grapefruit juice and naringin solution were 55% (P<0.001) and 75% (P<0.05) of that with water, respectively. Fexofenadine AUCs with grapefruit juice and particulate fractions were 57% (P<0.001), 96% (not significant (NS)), and 97% (NS) of that with water, respectively. Individuals tested in both studies (n=9 of 12) had highly reproducible fexofenadine AUC with water (r(2)=0.85, P<0.001) and extent of reduction of it with grapefruit juice (r(2)=0.72, P<0.01). Naringin most probably directly inhibited enteric OATP1A2 to decrease oral fexofenadine bioavailability. Inactivation of enteric CYP3A4 was probably not involved. Naringin appears to have sufficient safety, specificity, and sensitivity to be a clinical OATP1A2 inhibitor probe. Inherent OATP1A2 activity may be influenced by genetic factors. This appears to be the first report of a single dietary constituent clinically modulating drug transport.
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Affiliation(s)
- D G Bailey
- Lawson Health Research Institute, London Health Sciences Centre, University of Western Ontario, London, Ontario, Canada.
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Glaeser H, Bailey DG, Dresser GK, Gregor JC, Schwarz UI, McGrath JS, Jolicoeur E, Lee W, Leake BF, Tirona RG, Kim RB. Intestinal Drug Transporter Expression and the Impact of Grapefruit Juice in Humans. Clin Pharmacol Ther 2007; 81:362-70. [PMID: 17215845 DOI: 10.1038/sj.clpt.6100056] [Citation(s) in RCA: 325] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The goals of this study were to assess the extent of human intestinal drug transporter expression, determine the subcellular localization of the drug uptake transporter OATP1A2, and then to assess the effect of grapefruit juice consumption on OATP1A2 expression relative to cytochrome P450 3A4 and MDR1. Expression of drug uptake and efflux transporters was assessed using human duodenal biopsy samples. Fexofenadine uptake by different transporters was measured in a transporter-transfected cell line. We investigated the influence of grapefruit juice on pharmacokinetics of orally administered fexofenadine. The effect of grapefruit juice on the expression of intestinal transporters was determined using real-time polymerase chain reaction and Western blot analysis. In the duodenum of healthy volunteers, an array of CYP enzymes as well as uptake and efflux transporters was expressed. Importantly, uptake transporters thought to be liver-specific, such as OATP1B1 and 1B3, as well as OATP2B1 and 1A2 were expressed in the intestine. However, among OATP transporters, only OATP1A2 was capable of fexofenadine uptake when assessed in vitro. OATP1A2 colocalized with MDR1 to the brush border domain of enterocytes. Consumption of grapefruit juice concomitantly or 2 h before fexofenadine administration was associated with reduced oral fexofenadine plasma exposure, whereas intestinal expression of either OATP1A2 or MDR1 remained unaffected. In conclusion, an array of drug uptake and efflux transporters are expressed in the human intestine. OATP1A2 is likely the key intestinal uptake transporter for fexofenadine absorption whose inhibition results in the grapefruit juice effect. Although short-term grapefruit juice ingestion was associated with reduced fexofenadine availability, OATP1A2 or MDR1 expression was unaffected.
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Affiliation(s)
- H Glaeser
- Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
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Abstract
Despite their common use, it is not widely recognized that herbal medicines can alter the efficacy of coadministered prescription drugs. Constituents in herbs interact with nuclear receptors to enhance metabolizing enzyme and/or transporter activity leading to reduced drug concentrations. Although St John's wort was the first and most frequently reported source of induction-style herb-drug interactions, this knowledge has not yet changed its current availability. This type of interaction is likely to be relevant to other herbal products. Caregivers need to be aware of the issues and options for therapeutic management.
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Affiliation(s)
- Rommel G Tirona
- Division of Clinical Pharmacology, Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN, USA
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Schwarz UI, Seemann D, Oertel R, Miehlke S, Kuhlisch E, Fromm MF, Kim RB, Bailey DG, Kirch W. Grapefruit juice ingestion significantly reduces talinolol bioavailability. Clin Pharmacol Ther 2005; 77:291-301. [PMID: 15903127 DOI: 10.1016/j.clpt.2004.11.111] [Citation(s) in RCA: 108] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
OBJECTIVES Our objectives were to evaluate the effect of single and repeated grapefruit juice ingestion relative to water on the oral pharmacokinetics of the nonmetabolized and P-glycoprotein-transported drug talinolol in humans and to assess the potential impact of grapefruit juice ingestion on P-glycoprotein and intestinal uptake transporters. METHODS The oral pharmacokinetics of 50 mg talinolol was determined with water, with 1 glass of grapefruit juice (300 mL), and after 6 days of repeated grapefruit juice ingestion (900 mL/d) in 24 healthy white volunteers. MDR1 messenger ribonucleic acid and P-glycoprotein levels were measured in duodenal biopsy specimens obtained from 3 individuals before and after ingestion of grapefruit juice. Three commonly occurring polymorphisms in the MDR1 gene were also assessed. RESULTS A single glass of grapefruit juice decreased the talinolol area under the serum concentration-time curve (AUC), peak serum drug concentration (Cmax), and urinary excretion values to 56% (P < .001), 57% (P < .001), and 56% (P < .001), respectively, of those with water. Repeated ingestion of grapefruit juice had a similar effect (44% to 65% reduction; P < .01). Single or repeated juice ingestion did not affect renal clearance, elimination half-life, or time to reach Cmax (tmax). MDR1 messenger ribonucleic acid and P-glycoprotein levels in duodenal biopsy specimens were not affected by grapefruit juice. MDR1 genotypes (C1236T, G2677T/A, and C3435T) were not associated with altered talinolol pharmacokinetics. CONCLUSION Because both single and repeated ingestion of grapefruit juice lowered rather than increased talinolol AUC, our findings suggest that constituents in grapefruit juice preferentially inhibited an intestinal uptake process rather than P-glycoprotein. Moreover, grapefruit juice did not alter intestinal P-glycoprotein expression.
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Affiliation(s)
- Ute I Schwarz
- Institute of Clinical Pharmacology, Medical Faculty, Technical University, and Medical Department I, Technical University Hospital, Dresden.
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Bailey DG. Sun drop citrus soda and cyclosporine interaction: comments on causality and recommendations. Transplantation 2005; 79:747. [PMID: 15785395 DOI: 10.1097/01.tp.0000148914.13844.d9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Dresser GK, Kim RB, Bailey DG. Effect of Grapefruit Juice Volume on the Reduction of Fexofenadine Bioavailability: Possible Role of Organic Anion Transporting Polypeptides*. Clin Pharmacol Ther 2005; 77:170-7. [PMID: 15735611 DOI: 10.1016/j.clpt.2004.10.005] [Citation(s) in RCA: 130] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVE The purpose of this study was to elucidate the potential clinical relevance and mechanism(s) of action of 2 different volumes of grapefruit juice on the reduction of bioavailability of fexofenadine, a substrate of organic anion transporting polypeptides. METHODS Grapefruit juice or water at normal (300 mL) or high (1200 mL) volume was ingested concomitantly with 120 mg fexofenadine by 12 healthy volunteers in a randomized 4-way crossover study, and fexofenadine pharmacokinetics were determined over a period of 8 hours. RESULTS The 300-mL volume of grapefruit juice decreased the mean area under the plasma drug concentration-time curve (AUC) and the peak plasma drug concentration of fexofenadine to 58% (P < .001) and 53% (P < .001), respectively, of those with the corresponding volume of water, and 1200 mL grapefruit juice reduced these parameters to 36% ( P < .001) and 33% ( P < .001), respectively, of those with the corresponding volume of water. The 300-mL volume of grapefruit juice diminished the AUC of fexofenadine variably among individuals. This decline correlated with baseline AUC of fexofenadine with water at equivalent volume (r(2) = 0.97, P < .0001). The 1200-mL volume of grapefruit juice decreased the AUC of fexofenadine more than the 300-mL volume of grapefruit juice compared with the corresponding volume of water in each subject by a constant amount. Grapefruit juice, 300 mL and 1200 mL, reduced the coefficient of variation of the AUC of fexofenadine by 2-fold compared with that with a matching volume of water. CONCLUSIONS Grapefruit juice at a commonly consumed volume diminished the oral bioavailability of fexofenadine sufficiently to be pertinent clinically, likely by direct inhibition of uptake by intestinal organic anion transporting polypeptide A (OATP-A; new nomenclature, OATP1A2). A much higher volume caused an additional modest effect, possibly from reduced intestinal concentration and transit time of fexofenadine. This food-drug interaction appears to be novel and may be relevant to other fruit juices and drugs.
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Affiliation(s)
- George K Dresser
- Lawson Health Research Institute, London Health Sciences Centre, UK
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Goosen TC, Cillié D, Bailey DG, Yu C, He K, Hollenberg PF, Woster PM, Cohen L, Williams JA, Rheeders M, Dijkstra HP. Bergamottin contribution to the grapefruit juice?felodipine interaction and disposition in humans. Clin Pharmacol Ther 2004; 76:607-17. [PMID: 15592332 DOI: 10.1016/j.clpt.2004.08.019] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
OBJECTIVES Our objectives were to evaluate the contribution of bergamottin to the grapefruit juice-felodipine interaction and to characterize bergamottin disposition. METHODS In this study 250 mL grapefruit juice; 2-, 6-, or 12-mg capsules of bergamottin plus water; or water was administered with 5 mg extended-release felodipine to 11 volunteers in a partially randomized, 5-way crossover study. Plasma concentrations of felodipine, its primary metabolite (dehydrofelodipine), bergamottin, and 6',7'-dihydroxybergamottin were determined. RESULTS Grapefruit juice (containing 1.7 mg bergamottin) increased peak plasma concentration (C max ) and area under the plasma concentration-time curve (AUC) of felodipine by 89% (P < .025) and 54% (P < .025), respectively, compared with water. With 2 mg bergamottin, felodipine C max increased by 33% (P < .05). The increase by bergamottin was markedly variable among individuals (range, -33% to 125%). With 6 mg bergamottin, felodipine C max was enhanced by 35% (P < .025), and with 12 mg bergamottin, felodipine C max increased by 40% (P < .05) and AUC increased by 37% (P < .05) compared with water. Bergamottin measured in plasma after administration of 6 and 12 mg produced C max values of 2.1 and 5.9 ng/mL, respectively, and times to reach C max of 0.8 and 1.1 hours, respectively. The bergamottin metabolite 6',7'-dihydroxybergamottin was detected in plasma of some subjects after bergamottin administration. CONCLUSIONS Bergamottin enhanced the oral bioavailability of felodipine and may cause a clinically relevant drug interaction in susceptible individuals. Grapefruit juice-drug interactions likely also involve other furanocoumarins, possibly acting in combination by additive or synergistic mechanisms. Bergamottin has systemic availability and is metabolized in vivo to 6',7'-dihydroxybergamottin.
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Affiliation(s)
- Theunis C Goosen
- Department of Pharmacology, North-West University, Potchefstroom.
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Affiliation(s)
- David G Bailey
- Lawson Health Research Institute, London Health Sciences Centre, and Department of Medicine, University of Western Ontario, London, Ont
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Abstract
Grapefruit juice can alter oral drug pharmacokinetics by different mechanisms. Irreversible inactivation of intestinal cytochrome P450 (CYP) 3A4 is produced by commercial grapefruit juice given as a single normal amount (e.g. 200-300 mL) or by whole fresh fruit segments. As a result, presystemic metabolism is reduced and oral drug bioavailability increased. Enhanced oral drug bioavailability can occur 24 hours after juice consumption. Inhibition of P-glycoprotein (P-gp) is a possible mechanism that increases oral drug bioavailability by reducing intestinal and/or hepatic efflux transport. Recently, inhibition of organic anion transporting polypeptides by grapefruit juice was observed in vitro; intestinal uptake transport appeared decreased as oral drug bioavailability was reduced. Numerous medications used in the prevention or treatment of coronary artery disease and its complications have been observed or are predicted to interact with grapefruit juice. Such interactions may increase the risk of rhabdomyolysis when dyslipidemia is treated with the HMG-CoA reductase inhibitors atorvastatin, lovastatin, or simvastatin. Potential alternative agents are pravastatin, fluvastatin, or rosuvastatin. Such interactions might also cause excessive vasodilatation when hypertension is managed with the dihydropyridines felodipine, nicardipine, nifedipine, nisoldipine, or nitrendipine. An alternative agent could be amlodipine. In contrast, the therapeutic effect of the angiotensin II type 1 receptor antagonist losartan may be reduced by grapefruit juice. Grapefruit juice interacting with the antidiabetic agent repaglinide may cause hypoglycemia, and interaction with the appetite suppressant sibutramine may cause elevated BP and HR. In angina pectoris, administration of grapefruit juice could result in atrioventricular conduction disorders with verapamil or attenuated antiplatelet activity with clopidrogel. Grapefruit juice may enhance drug toxicity for antiarrhythmic agents such as amiodarone, quinidine, disopyramide, or propafenone, and for the congestive heart failure drug, carvediol. Some drugs for the treatment of peripheral or central vascular disease also have the potential to interact with grapefruit juice. Interaction with sildenafil, tadalafil, or vardenafil for erectile dysfunction, may cause serious systemic vasodilatation especially when combined with a nitrate. Interaction between ergotamine for migraine and grapefruit juice may cause gangrene or stroke. In stroke, interaction with nimodipine may cause systemic hypotension. If a drug has low inherent oral bioavailability from presystemic metabolism by CYP3A4 or efflux transport by P-gp and the potential to produce serious overdose toxicity, avoidance of grapefruit juice entirely during pharmacotherapy appears mandatory. Although altered drug response is variable among individuals, the outcome is difficult to predict and avoiding the combination will guarantee toxicity is prevented. The elderly are at particular risk, as they are often prescribed medications and frequently consume grapefruit juice.
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Affiliation(s)
- David G Bailey
- Department of Medicine and Lawson Health Research Institute, London Health Sciences Centre, London, Ontario, Canada.
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McEvoy JM, Doherty AM, Sheridan JJ, Bailey DG, Blair IS, McDowell DA. The effects of treating bovine hide with steam at subatmospheric pressure on bacterial numbers and leather quality. Lett Appl Microbiol 2003; 37:344-8. [PMID: 12969501 DOI: 10.1046/j.1472-765x.2003.01406.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
AIMS To examine the effect of subatmospheric steam treatment on total viable counts (TVCs) on bovine hide and on the quality of derived leather. METHODS AND RESULTS Pieces of bovine hide were heated to 75 degrees C (+/-2 degrees C) (n = 3) or 80 degrees C (+/-2 degrees C) (n = 3) for periods of 1, 10 or 20 s by the application of steam at subatmospheric pressure in a laboratory scale apparatus. Treated hide pieces and untreated controls were tanned and the quality of leather was assessed. Treatment at 80 degrees C (T80) reduced the TVC on hide pieces by 2.95 (1 s), 3.33 (10 s) and 3.99 (20 s) log10 CFU cm-2 (P > 0.05). Treatment at 75 degrees C (T75) reduced the TVC on hide pieces by 1.87 (1 s), 2.51 (10 s) and 2.56 (20 s) log10 CFU cm-2 (P > 0.05). The grain on all treated hides was damaged resulting in sueding on derived leather. Sueding was observed on 100% of surfaces from T80-treated samples and on 18 (1 s) to 84% (20 s) of the surfaces of T75 samples. CONCLUSIONS The magnitude of TVC reductions achieved using T75 and T80 could limit the impact and scale of contamination transfer to the carcass during dehiding. However, because of the sueding observed on derived leather, it is unlikely that either T75 or T80 would be a commercially valid operation during routine slaughter operations. SIGNIFICANCE AND IMPACT OF THE STUDY Hide decontamination would provide an important critical control point for beef processing, however there are currently no commercially available treatments.
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Affiliation(s)
- J M McEvoy
- Teagasc, The National Food Centre, Ashtown, Dublin, Ireland.
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Abstract
Grapefruit juice produces mechanism-based inhibition of intestinal drug metabolism when consumed in normal quantities. This can produce clinically important increases in oral drug bioavailability when coadministered with substrates of cytochrome p450 3A4 (CYP3A4) that undergo high presystemic metabolism. Furanocoumarins such as bergamottin and 6',7'-dihydroxybergamottin have been identified as probable active constituents. Grapefruit juice may also inhibit intestinal P-glycoprotein-mediated efflux transport of drugs such as cyclosporine to increase its oral bioavailability. However, grapefruit juice does not enhance the absorption of digoxin, a prototypical P-glycoprotein substrate, likely because it has high inherent oral bioavailability. Grapefruit and other fruit juices have recently been shown to be potent in vitro inhibitors of a number of organic anion-transporting polypeptides (OATPs). These juices were also found to decrease the absorption of the nonmetabolized OATP substrate, fexofenadine. Taken together, the data support inhibition of intestinal uptake transporters by fruit juices to decrease drug bioavailability. This would represent a new mechanism for food-drug interactions. These findings with grapefruit and other fruit juices continue to enhance our understanding of the complex nature of food-drug interactions, and their possible influence on the clinical effects of medications.
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Affiliation(s)
- G K Dresser
- Department of Medicine, London Health Sciences Centre, and University of Western Ontario, London, Ontario, Canada.
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Bailey DG, Dresser GK, Bend JR. Bergamottin, lime juice, and red wine as inhibitors of cytochrome P450 3A4 activity: comparison with grapefruit juice. Clin Pharmacol Ther 2003; 73:529-37. [PMID: 12811362 DOI: 10.1016/s0009-9236(03)00051-1] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
OBJECTIVES Our objective was to assess the importance of bergamottin in drug interactions through comparisons between grapefruit juice and lime juice and the potential for drug interactions with red wine. METHODS Bergamottin content and in vitro reversible/irreversible inhibition of cytochrome P450 (CYP) 3A4 monooxygenase activities were determined for grapefruit and lime juices. The oral pharmacokinetics of felodipine and its primary metabolite (dehydrofelodipine) were determined with 250 mL of grapefruit juice, one quarter-strength lime juice, red wine, or water in a randomized crossover study. RESULTS Bergamottin concentrations in grapefruit and lime juices were 25 and 100 micromol/L, respectively. For reversible inhibition, log volume-residual CYP3A4 activity relationships for grapefruit and lime juices had negative linear slopes that were parallel. The curve for grapefruit juice was 4.0-fold right-shifted, as compared with that for lime juice. For irreversible inhibition, the curves for grapefruit and lime juices were 4.0- and 1.4-fold left-shifted, as compared with those for reversible inhibition, respectively. Grapefruit juice increased the mean felodipine area under the plasma concentration-time curve (AUC) (mean +/- SE, 55 +/- 9 nmol. h/L versus 29 +/- 6 nmol. h/L; P <.05) and the plasma peak drug concentration (16 +/- 3 nmol/L versus 8 +/- 2 nmol/L, P <.05) and decreased the dehydrofelodipine/felodipine AUC ratio compared with those of water. One quarter-strength lime juice did not alter mean values. However, the changes in individual felodipine AUC after grapefruit juice and lime juice correlated (r(2) = 0.95) with a low slope (0.36). One quarter-strength lime juice more than doubled felodipine AUC and plasma peak drug concentration in 2 subjects. Red wine prolonged mean felodipine time to plasma peak drug concentration. Felodipine concentrations were low and peaked abruptly in 4 subjects. Adverse effects occurred in 1 subject. CONCLUSIONS Bergamottin and reversible inhibition are not the primary substance and mechanism responsible for inhibition of CYP3A4 activity clinically. Red wine can cause dose dumping of extended-release felodipine in certain individuals.
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Affiliation(s)
- David G Bailey
- Department of Medicine, London Health Sciences Centre, Ontario, Canada.
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Gehring AG, Bailey DG, Caveng RF, Vreeland RH. A Rapid Method for the Estimation of Bile Salts in Complex Tanning Brines by RPHPLC. J LIQ CHROMATOGR R T 2003. [DOI: 10.1081/jlc-120020091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Andrew G. Gehring
- a Eastern Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture , 600 E. Mermaid Lane, Wyndmoor , Pennsylvania , 19038 , USA
| | - David G. Bailey
- a Eastern Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture , 600 E. Mermaid Lane, Wyndmoor , Pennsylvania , 19038 , USA
| | - Rocco F. Caveng
- a Eastern Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture , 600 E. Mermaid Lane, Wyndmoor , Pennsylvania , 19038 , USA
| | - Russell H. Vreeland
- b Department of Biology , West Chester University , West Chester , Pennsylvania , USA
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Dresser GK, Bailey DG. A basic conceptual and practical overview of interactions with highly prescribed drugs. Can J Clin Pharmacol 2003; 9:191-8. [PMID: 12584577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
Drug interactions are frequently the result of altered activity of the mechanism(s) responsible for drug elimination. These include drug metabolism mediated by a select group of cytochrome P450 enzymes (CYP3A4, CYP2D6, CYP2C9, CYP2C19, CYP1A2) and drug transporters (P-glycoprotein). Adverse drug interactions can result from induction (loss of therapeutic benefit) or inhibition (increased toxicity from excessive effect) of drug elimination. CYPs and P-glycoprotein are discussed individually with regards to their characteristics, frequently prescribed drug substrates, inducers and inhibitors, and important adverse drug events. The potential for important drug interactions can be predicted based on the properties of the causative agent (oral bioavailability, mechanism of elimination, seriousness of adverse event) and the interacting agent. Consequently, drug interactions can be prevented by avoiding concomitant administration of interacting substances or possibly implementing alternative therapeutic strategies. Furthermore, susceptibility to adverse events depends not only on the interacting substances, but also on the patient and the method of drug administration. Commonly prescribed drugs that are unlikely to cause a drug interaction involving CYPs or P-glycoprotein are also discussed.
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Affiliation(s)
- George K Dresser
- Department of Medicine, University of Western Ontario, Lawson Health Research Institute, London, Canada
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Dresser GK, Wacher V, Wong S, Wong HT, Bailey DG. Evaluation of peppermint oil and ascorbyl palmitate as inhibitors of cytochrome P4503A4 activity in vitro and in vivo. Clin Pharmacol Ther 2002; 72:247-55. [PMID: 12235445 DOI: 10.1067/mcp.2002.126409] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVES Our study was designed to determine the effect of peppermint oil and ascorbyl palmitate on cytochrome P4503A4 (CYP3A4) activity in vitro and oral bioavailability of felodipine in humans. METHODS Reversible and mechanism-based inhibitions of nifedipine oxidation were studied in human liver microsomes. The oral pharmacokinetics of felodipine and its dehydrofelodipine metabolite were determined in 12 healthy volunteers after administration of felodipine, 10-mg extended-release tablet, with grapefruit juice (300 mL), peppermint oil (600 mg), ascorbyl palmitate (500 mg), or water in a randomized 4-way crossover study. RESULTS Peppermint oil (inhibition constant [K(i)] = 35.9 +/- 3.3 microg/mL, mean +/- SEM) and 2 constituents, menthol (K(i) = 87.0 +/- 7.0 micromol/L), and menthyl acetate (K(i) = 124.0 +/- 7.0 micromol/L), produced reversible inhibition of nifedipine oxidation. Ascorbyl palmitate was more potent (K(i) = 12.3 +/- 0.5 micromol/L). None of these substances were mechanism-based inhibitors. Grapefruit juice and peppermint oil increased the area under the curve (AUC) values of felodipine to 173% (range, 94%-280%; P <.01) and 140% (range, 77%-262%; P <.05), respectively, of those with water. They augmented the peak plasma concentration (C(max)) of felodipine and the AUC and C(max) of dehydrofelodipine but did not alter the half-life (t(1/2)) of either substance. Grapefruit juice decreased the dehydrofelodipine/felodipine AUC ratio, but peppermint oil did not. Ascorbyl palmitate did not change the pharmacokinetics of felodipine or dehydrofelodipine compared with water. CONCLUSIONS Peppermint oil, menthol, menthyl acetate, and ascorbyl palmitate were moderately potent reversible inhibitors of in vitro CYP3A4 activity. Grapefruit juice increased the oral bioavailability of felodipine by inhibition of CYP3A4-mediated presystemic drug metabolism. Peppermint oil may also have acted by this mechanism. However, this requires further investigation. Ascorbyl palmitate did not inhibit CYP3A4 activity in vivo.
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Affiliation(s)
- George K Dresser
- Department of Medicine, London Health Sciences Centre, University of Western Ontario, London, Ontario, Canada
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Dresser GK, Bailey DG, Leake BF, Schwarz UI, Dawson PA, Freeman DJ, Kim RB. Fruit juices inhibit organic anion transporting polypeptide-mediated drug uptake to decrease the oral availability of fexofenadine. Clin Pharmacol Ther 2002; 71:11-20. [PMID: 11823753 DOI: 10.1067/mcp.2002.121152] [Citation(s) in RCA: 388] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVES Our objective was to examine the effect of different fruits and their constituents on P-glycoprotein and organic anion transporting polypeptide (OATP) activities in vitro and on drug disposition in humans. METHODS P-glycoprotein-mediated digoxin or vinblastine efflux was determined in polarized epithelial cell monolayers. OATP-mediated fexofenadine uptake was measured in a transfected cell line. The oral pharmacokinetics of 120 mg fexofenadine was assessed with water, 25%-strength grapefruit juice, or normal-strength grapefruit, orange, or apple juices (1.2 L over 3 hours) in a randomized 5-way crossover study in 10 healthy subjects. RESULTS Grapefruit juice and segments and apple juice at 5% of normal strength did not alter P-glycoprotein activity. Grapefruit extract reduced transport. 6',7'-Dihydroxybergamottin had modest inhibitory activity (50% inhibitory concentration [IC(50)], 33 micromol/L). In contrast, grapefruit, orange, and apple juices at 5% of normal strength markedly reduced human OATP and rat oatp activity. 6',7'-Dihydroxybergamottin potently inhibited rat oatp3 and oatp1 (IC(50), 0.28 micromol/L). Other furanocoumarins and bioflavonoids also reduced rat oatp3 activity. Grapefruit, orange, and apple juices decreased the fexofenadine area under the plasma concentration-time curve (AUC), the peak plasma drug concentration (C(max)), and the urinary excretion values to 30% to 40% of those with water, with no change in the time to reach C(max), elimination half-life, renal clearance, or urine volume in humans. Change in fexofenadine AUC with juice was variable among individuals and inversely dependent on value with water. CONCLUSIONS Fruit juices and constituents are more potent inhibitors of OATPs than P-glycoprotein activities, which can reduce oral drug bioavailability. Results support a new model of intestinal drug absorption and mechanism of food-drug interaction.
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Affiliation(s)
- George K Dresser
- Department of Medicine, University of Western Ontario, London, Ontario, Canada
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Abstract
OBJECTIVES Our objective was to compare the interactions of red wine and grapefruit juice with cisapride. METHODS The oral pharmacokinetics of cisapride, its norcisapride metabolite, and electrocardiographic QTc interval were determined over a 24-hour period after administration of cisapride 10 mg with 250 mL grapefruit juice, red wine (cabernet sauvignon), or water in a randomized 3-way crossover study in 12 healthy men. RESULTS The cisapride area under the concentration-time curve (AUC) and the maximum plasma drug concentration after single-dose administration (C(max)) with grapefruit juice were 151% (P <.01) and 168% (P <.001), respectively, of those with water. The increase in cisapride AUC and C(max) was variable among individuals; however, cisapride AUC and C(max) were enhanced by the same proportion. The time to reach maximum concentration after drug administration (t(max)) and the apparent elimination half-life (t((1/2)) for cisapride and the pharmacokinetics of norcisapride were not altered. Norcisapride/cisapride ratios were reduced. Cisapride AUC and C(max) with red wine were 115% (difference not statistically significant) and 107% (difference not statistically significant), respectively, of those with water. The cisapride t(max) was slightly longer. Cisapride t((1/2)) and norcisapride pharmacokinetics were not different. The norcisapride/cisapride ratio at cisapride C(max) was lower. One subject had a doubling in cisapride AUC and C(max) and a decrease in norcisapride/cisapride ratios with red wine and also had the largest interaction with grapefruit juice. QTc interval was unchanged in all treatment groups and individuals. CONCLUSIONS A single glass of grapefruit juice produced an individual-dependent variable increase in the systemic availability of cisapride by inhibition of intestinal cytochrome P450 3A4 (CYP3A4) activity. The identical volume of red wine caused only minor changes in cisapride pharmacokinetics despite some inhibition of CYP3A4 in most individuals. However, even this amount of red wine may cause a marked interaction similar to that for grapefruit juice in individuals with a preexisting high intestinal CYP3A4 content.
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Affiliation(s)
- E M Offman
- Departments of Medicine and Pharmacology and Toxicology, London Health Sciences Centre and the University of Western Ontario, Canada
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Malhotra S, Bailey DG, Paine MF, Watkins PB. Seville orange juice-felodipine interaction: comparison with dilute grapefruit juice and involvement of furocoumarins. Clin Pharmacol Ther 2001; 69:14-23. [PMID: 11180034 DOI: 10.1067/mcp.2001.113185] [Citation(s) in RCA: 140] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVE Our objective was to determine whether Seville orange juice produces a grapefruit juice-like interaction with felodipine and whether bergamottin, 6',7'-dihydroxybergamottin, or other furocoumarins are involved. METHODS In a randomized three-way crossover design, 10 volunteers received a felodipine 10-mg extended-release tablet with 240 mL of Seville orange juice, dilute grapefruit juice (that contained equivalent total molar concentrations of bergamottin plus 6',7'-dihydroxybergamottin), or common orange juice (negative control). The pharmacokinetics of felodipine and its dehydrofelodipine metabolite were determined. Juice concentrations of furocoumarins were measured. CYP3A4 inhibitory activity of newly identified furocoumarins was assessed. RESULTS The felodipine area under the plasma concentration-time curve was increased by 76% and 93% after Seville orange juice and grapefruit juice ingestion, respectively, compared with common orange juice. The effects of Seville orange juice and grapefruit juice were similar in that the felodipine maximum concentration was augmented while the terminal elimination half-life was unchanged and the dehydrofelodipine area under the plasma concentration time-curve was increased, but the dehydrofelodipine-felodipine area under the plasma concentration-time curve ratio was reduced. Bergamottin and 6',7'-dihydroxybergamottin concentrations were 5 and 36 micromol/L, respectively, in Seville orange juice and were 16 and 23 micromol/L, respectively, in dilute grapefruit juice. A newly identified furocoumarin, bergapten, was detected only in Seville orange juice (31 micromol/L), and it was found to be a mechanism-based inhibitor of recombinant CYP3A4. Relative to the control, 6',7'-dihydroxybergamottin (10 micromol/L) inhibited CYP3A4 activity in cultured intestinal epithelial cells by 93%, whereas bergapten (10 micromol/L) inhibited the activity by only 34%. CONCLUSIONS Seville orange juice and grapefruit juice interact with felodipine by a common mechanism, which is probably inactivation of intestinal CYP3A4. Bergamottin and 6',7'-dihydroxybergamottin may be "marker substances" in foods for this interaction. The lack of interaction between Seville orange juice and cyclosporine (INN, ciclosporin) suggests that grapefruit juice may also inhibit intestinal P-glycoprotein, whereas Seville orange juice may selectively "knock out" intestinal CYP3A4.
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Affiliation(s)
- S Malhotra
- Department of Pharmacology, University of Michigan, Ann Arbor, USA
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Bailey DG, Dresser GK, Kreeft JH, Munoz C, Freeman DJ, Bend JR. Grapefruit-felodipine interaction: effect of unprocessed fruit and probable active ingredients. Clin Pharmacol Ther 2000; 68:468-77. [PMID: 11103749 DOI: 10.1067/mcp.2000.110774] [Citation(s) in RCA: 110] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVES To determine whether unprocessed grapefruit can cause a drug interaction, whether the active ingredients are naturally occurring, and whether specific furanocoumarins or flavonoids are involved. METHODS The oral pharmacokinetics of felodipine and its dehydrofelodipine metabolite were determined after administration of felodipine 10 mg extended-release tablet with 250 mL commercial grapefruit juice, homogenized grapefruit segments, or extract of segment-free parts equivalent to one unprocessed fruit or water in a randomized four-way crossover study. Inhibition of recombinant CYP3A4 by furanocoumarins (bergamottin, 6',7'-epoxybergamottin, 6',7'-dihydroxybergamottin) and flavonoids (naringenin optical isomers) was determined. Furanocoumarin and naringenin precursor (naringin) concentrations were measured in each grapefruit treatment. RESULTS Felodipine AUC with commercial grapefruit juice, grapefruit segments, or grapefruit extract was on average 3-fold higher than that with water. Felodipine peak concentration was higher, but the half-life was unchanged. The dehydrofelodipine/felodipine AUC ratio was reduced. The furanocoumarins produced mechanism-based and competitive inhibition of CYP3A4. Bergamottin was the most potent mechanism-based inhibitor. Naringenin isomers produced only competitive inhibition. Bergamottin, 6',7'-dihydroxybergamottin, and naringin concentrations varied among grapefruit treatments but were sufficient to inhibit markedly in vitro CYP3A4 activity. CONCLUSIONS Unprocessed grapefruit can cause a drug interaction with felodipine. The active ingredients are naturally occurring in the grapefruit. Bergamottin is likely important in drug interactions with commercial grapefruit juice. 6',7'-Dihydroxybergamottin and naringin may be more important in grapefruit segments because they are present in higher concentrations. Any therapeutic concern for a drug interaction with commercial grapefruit juice should now be extended to include whole fruit and possibly confectioneries made from grapefruit peel.
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Affiliation(s)
- D G Bailey
- Department of Medicine, London Health Sciences Centre, University of Western Ontario, Canada.
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Abstract
BACKGROUND Grapefruit juice can increase the oral bioavailability of a broad range of medications. This interaction has not been assessed in the elderly. METHODS Twelve healthy elderly people (70 to 83 years of age) were administered 5 mg felodipine extended release with 250 mL grapefruit juice or water in a single-dose study. Subsequently, 6 of these people received 2.5 mg felodipine for 2 days, followed by 5 mg felodipine for 6 days with 250 mL grapefruit juice or water in a steady-state study. Plasma concentrations of felodipine and dehydrofelodipine metabolite, blood pressure, and heart rate were measured over 24 hours after single and final steady-state dose. RESULTS Mean felodipine area under the curve and maximum concentration were 2.9-fold and 4.0-fold greater, respectively, with grapefruit juice in both studies. Interindividual variability in the extent of the interaction was high. Felodipine apparent elimination half-life was not altered. Dehydrofelodipine area under the curve and maximum concentration were increased and dehydrofelodipine/felodipine area under the curve ratio was reduced. Systolic and diastolic blood pressures were lower with grapefruit juice in the single-dose study, whereas they were not different between treatments in the steady-state study. Curvilinear relationships existed between plasma felodipine concentration and changes in systolic and diastolic blood pressures. Heart rates were higher with grapefruit juice in both studies; however, this effect was greater and more prolonged at steady state. CONCLUSIONS A normal dietary amount of grapefruit juice produced a pronounced, unpredictable, and sustained pharmacokinetic interaction with felodipine by reducing its presystemic metabolism in the elderly. The different blood pressure results between the studies can be explained by felodipine concentration-blood pressure response relationships. The elderly should be particularly cautioned about concomitant grapefruit juice and felodipine ingestion.
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Affiliation(s)
- G K Dresser
- Department of Medicine and Pharmacology and Toxicology, London Health Sciences Centre and University of Western Ontario, Canada
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Bailey DG, Dresser GK. Grapefruit juice-lovastatin interaction. Clin Pharmacol Ther 2000; 67:690. [PMID: 10872652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
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Abstract
Drug interactions occur when the efficacy or toxicity of a medication is changed by administration of another substance. Pharmacokinetic interactions often occur as a result of a change in drug metabolism. Cytochrome P450 (CYP) 3A4 oxidises a broad spectrum of drugs by a number of metabolic processes. The location of CYP3A4 in the small bowel and liver permits an effect on both presystemic and systemic drug disposition. Some interactions with CYP3A4 inhibitors may also involve inhibition of P-glycoprotein. Clinically important CYP3A4 inhibitors include itraconazole, ketoconazole, clarithromycin, erythromycin, nefazodone, ritonavir and grapefruit juice. Torsades de pointes, a life-threatening ventricular arrhythmia associated with QT prolongation, can occur when these inhibitors are coadministered with terfenadine, astemizole, cisapride or pimozide. Rhabdomyolysis has been associated with the coadministration of some 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors ('statins') and CYP3A4 inhibitors. Symptomatic hypotension may occur when CYP3A4 inhibitors are given with some dihydropyridine calcium antagonists, as well with the phosphodiesterase inhibitor sildenafil. Excessive sedation can result from concomitant administration of benzodiazepine (midazolam, triazolam, alprazolam or diazepam) or nonbenzodiazepine (zopiclone and buspirone) hypnosedatives with CYP3A4 inhibitors. Ataxia can occur with carbamazepine, and ergotism with ergotamine, following the addition of a CYP3A4 inhibitor. Beneficial drug interactions can occur. Administration of a CYP3A4 inhibitor with cyclosporin may allow reduction of the dosage and cost of the immunosuppressant. Certain HIV protease inhibitors, e.g. saquinavir, have low oral bioavailability that can be profoundly increased by the addition of ritonavir. The clinical importance of any drug interaction depends on factors that are drug-, patient- and administration-related. Generally, a doubling or more in plasma drug concentration has the potential for enhanced adverse or beneficial drug response. Less pronounced pharmacokinetic interactions may still be clinically important for drugs with a steep concentration-response relationship or narrow therapeutic index. In most cases, the extent of drug interaction varies markedly among individuals; this is likely to be dependent on interindividual differences in CYP3A4 tissue content, pre-existing medical conditions and, possibly, age. Interactions may occur under single dose conditions or only at steady state. The pharmacodynamic consequences may or may not closely follow pharmacokinetic changes. Drug interactions may be most apparent when patients are stabilised on the affected drug and the CYP3A4 inhibitor is then added to the regimen. Temporal relationships between the administration of the drug and CYP3A4 inhibitor may be important in determining the extent of the interaction.
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Affiliation(s)
- G K Dresser
- Department of Medicine, London Health Sciences Centre and The University of Western Ontario, Canada
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Haas MJ, Bailey DG, Baker W, Berka TR, Cichowicz DJ, Derewenda ZS, Genuario RR, Joerger RD, Klein RR, Scott K, Woolf DJ. Biochemical and molecular biological characterization of a lipase produced by the fungusRhizopus delemar. ACTA ACUST UNITED AC 1999. [DOI: 10.1002/(sici)1521-4133(199910)101:10<364::aid-lipi364>3.0.co;2-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Hall SD, Thummel KE, Watkins PB, Lown KS, Benet LZ, Paine MF, Mayo RR, Turgeon DK, Bailey DG, Fontana RJ, Wrighton SA. Molecular and physical mechanisms of first-pass extraction. Drug Metab Dispos 1999; 27:161-6. [PMID: 9929497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023] Open
Abstract
This is a report of a symposium held at the March 1997 meeting of the American Society for Pharmacology and Therapeutics in San Diego. Our understanding of the events that control first-pass drug elimination in humans has increased tremendously by two sequential discoveries. First, cytochrome P-450s 3A4 and 5 are expressed at high concentrations in both hepatocytes and upper intestinal enterocytes, and therefore limit the systemic availability of many drugs. Second, P-glycoprotein is expressed at the lumenal surface of the intestinal epithelium and therefore also acts to oppose the absorption of unchanged drug. The following discussion brings together our current understandings of these interrelated phenomena to aid a more complete picture of how they may contribute both qualitatively and quantitatively to first-pass elimination.
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Affiliation(s)
- S D Hall
- Department of Medicine, Indiana University School of Medicine, Indianapolis, USA.
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Bailey DG, Kreeft JH, Munoz C, Freeman DJ, Bend JR. Grapefruit juice-felodipine interaction: effect of naringin and 6',7'-dihydroxybergamottin in humans. Clin Pharmacol Ther 1998; 64:248-56. [PMID: 9757148 DOI: 10.1016/s0009-9236(98)90173-4] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To test whether naringin or 6',7'-dihydroxybergamottin is a major active substance in grapefruit juice-felodipine interaction in humans. METHODS Grapefruit juice was separated by means of centrifugation and filtration into supernatant and particulate fractions, which were then assayed for naringin and 6',7'-dihydroxybergamottin. The effect of these fractions, grapefruit juice (containing comparable amounts of both fractions), and water on the pharmacokinetics of oral felodipine were assessed in 12 healthy men in a randomized, 4-way crossover study. RESULTS The amounts of naringin and 6',7'-dihydroxybergamottin in the supernatant fraction (148 mg and 1.85 mg) were greater than in the particulate fraction (7 mg and 0.60 mg). The area under the plasma concentration-time curve (AUC) and the peak concentration (Cmax) of felodipine were higher with supernatant fraction (81 nmol.h/L and 20 nmol/L), particulate fraction (117 nmol.h/L and 24 nmol/L), and grapefruit juice (130 nmol.h/L and 33 nmol/L) compared with water (53 nmol.h/L and 11 nmol/L). However, the supernatant fraction had a lower AUC for felodipine and a similar Cmax of felodipine relative to the particulate fraction. The supernatant fraction neither augmented the AUC of the primary metabolite dehydrofelodipine nor decreased the AUC ratio of dehydrofelodipine to felodipine compared with water. Individually the supernatant fraction consistently produced lower felodipine AUC and Cmax compared with grapefruit juice. In contrast, the particulate fraction had values ranging from more than grapefruit juice to less than supernatant fraction. CONCLUSIONS Naringin and 6',7'-dihydroxybergamottin are not the major active ingredients, although they may contribute to the grapefruit juice-felodipine interaction. The variable effect with the particulate fraction may result from erratic bioavailability of unidentified primary active substances. The findings show the importance of in vivo testing to determine the ingredients in grapefruit juice responsible for inhibition of cytochrome P450 3A4 in humans.
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Affiliation(s)
- D G Bailey
- Department of Medicine, London Health Sciences Centre, Ontario, Canada.
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Abstract
The novel finding that grapefruit juice can markedly augment oral drug bioavailability was based on an unexpected observation from an interaction study between the dihydropyridine calcium channel antagonist, felodipine, and ethanol in which grapefruit juice was used to mask the taste of the ethanol. Subsequent investigations showed that grapefruit juice acted by reducing presystemic felodipine metabolism through selective post-translational down regulation of cytochrome P450 3A4 (CYP3A4) expression in the intestinal wall. Since the duration of effect of grapefruit juice can last 24 h, repeated juice consumption can result in a cumulative increase in felodipine AUC and Cmax. The high variability of the magnitude of effect among individuals appeared dependent upon inherent differences in enteric CYP3A4 protein expression such that individuals with highest baseline CYP3A4 had the highest proportional increase. At least 20 other drugs have been assessed for an interaction with grapefruit juice. Medications with innately low oral bioavailability because of substantial presystemic metabolism mediated by CYP3A4 appear affected by grapefruit juice. Clinically relevant interactions seem likely for most dihydropyridines, terfenadine, saquinavir, cyclosporin, midazolam, triazolam and verapamil and may also occur with lovastatin, cisapride and astemizole. The importance of the interaction appears to be influenced by individual patient susceptibility, type and amount of grapefruit juice and administration-related factors. Although in vitro findings support the flavonoid, naringin, or the furanocoumarin, 6',7'-dihydroxybergamottin, as being active ingredients, a recent investigation indicated that neither of these substances made a major contribution to grapefruit juice-drug interactions in humans.
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Affiliation(s)
- D G Bailey
- Department of Medicine, London Health Sciences Centre, Ontario, Canada
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Lown KS, Bailey DG, Fontana RJ, Janardan SK, Adair CH, Fortlage LA, Brown MB, Guo W, Watkins PB. Grapefruit juice increases felodipine oral availability in humans by decreasing intestinal CYP3A protein expression. J Clin Invest 1997; 99:2545-53. [PMID: 9153299 PMCID: PMC508096 DOI: 10.1172/jci119439] [Citation(s) in RCA: 437] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The increase in oral availability of felodipine and other commonly used medications when taken with grapefruit juice has been assumed to be due to inhibition of CYP3A4, a cytochrome P450 that is present in liver and intestine. To evaluate the effect of repeated grapefruit juice ingestion on CYP3A4 expression, 10 healthy men were given 8 oz of grapefruit juice three times a day for 6 d. Before and after receiving grapefruit juice, small bowel and colon mucosal biopsies were obtained endoscopically, oral felodipine kinetics were determined, and liver CYP3A4 activity was measured with the [14C N-methyl] erythromycin breath test in each subject. Grapefruit juice did not alter liver CYP3A4 activity, colon levels of CYP3A5, or small bowel concentrations of P-glycoprotein, villin, CYP1A1, and CYP2D6. In contrast, the concentration of CYP3A4 in small bowel epithelia (enterocytes) fell 62% (P = 0.0006) with no corresponding change in CYP3A4 mRNA levels. In addition, enterocyte concentrations of CYP3A4 measured before grapefruit juice consumption correlated with the increase in Cmax when felodipine was taken with either the 1st or the 16th glass of grapefruit juice relative to water (r = 0. 67, P = 0.043, and r = 0.71, P = 0.022, respectively). We conclude that a mechanism for the effect of grapefruit juice on oral felodipine kinetics is its selective downregulation of CYP3A4 in the small intestine.
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Affiliation(s)
- K S Lown
- Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan 48109, USA
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Rau SE, Bend JR, Arnold MO, Tran LT, Spence JD, Bailey DG. Grapefruit juice-terfenadine single-dose interaction: magnitude, mechanism, and relevance. Clin Pharmacol Ther 1997; 61:401-9. [PMID: 9129557 DOI: 10.1016/s0009-9236(97)90190-9] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVE To investigate the single dose-response effects of grapefruit juice on terfenadine disposition and electrocardiographic measurements. METHODS Twelve healthy males received 250 ml water or regular- or double-strength grapefruit juice with 60 mg terfenadine in a randomized crossover trial. Plasma concentrations of the cardiotoxic agent terfenadine and the active antihistaminic metabolite terfenadine carboxylate were determined over 8 hours. The QTc interval was monitored. RESULTS Terfenadine concentrations were measurable (> 1 ng/ml) in 27 (20%; p < 0.001) and 39 (30%; p < 0.001) samples from individuals treated with regular- and double-strength grapefruit juice, respectively, compared to only four (3%) samples with water. Terfenadine plasma peak drug concentration (Cmax) was also higher. Terfenadine carboxylate area under the plasma drug concentration-time curve (AUC), Cmax, and time to reach Cmax (tmax) were increased by both strengths of juice. However, terfenadine carboxylate apparent elimination half-life (t1/2) was not altered. The magnitude of the interaction of terfenadine carboxylate AUC and Cmax ranged severalfold and correlated among individuals for regular-strength (r2 = 0.87; p < 0.0001) and double-strength (r2 = 0.78; p < 0.0001) grapefruit juice. No differences in the pharmacokinetics of terfenadine and terfenadine carboxylate were observed between the two strengths of grapefruit juice. QTc interval was not altered. CONCLUSIONS A normal amount of regular-strength grapefruit juice produced maximum single-dose effects on terfenadine and carboxylic acid metabolite pharmacokinetics. The mechanism likely involved reduced presystemic drug elimination by inhibition of more than one metabolic pathway. The extent of the interaction was not sufficient to produce electrocardiographic changes. However, the pharmacokinetic effects were highly variable among individuals. This study further enhances the awareness of the potential for a serious interaction between grapefruit juice and terfenadine.
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Affiliation(s)
- S E Rau
- Department of Pharmacology and Toxicology, University of Western Ontario, London, Canada
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Bailey DG, Bend JR, Arnold JM, Tran LT, Spence JD. Erythromycin-felodipine interaction: magnitude, mechanism, and comparison with grapefruit juice. Clin Pharmacol Ther 1996; 60:25-33. [PMID: 8689808 DOI: 10.1016/s0009-9236(96)90163-0] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
OBJECTIVE To investigate a potentially marked effect by erythromycin on felodipine pharmacokinetics, to characterize the mechanism, and to compare the interaction with that between grapefruit juice and felodipine. METHODS Felodipine, 10 mg extended release, was administered with 250 ml water, 250 mg erythromycin, or 250 ml grapefruit juice in a randomized crossover study of 12 healthy men. Erythromycin base, 250 mg four times a day, was started the day before and continued on that study day. Pharmacokinetic values of felodipine, the primary metabolite dehydrofelodipine, and the major secondary derivative M3 metabolite were studied. RESULTS Compared with water, erythromycin produced severalfold higher felodipine area under the plasma drug concentration-time profile (AUC), plasma peak drug concentration (Cmax), and apparent elimination half-life (t1/2); however, the effect was variable among individuals. Erythromycin augmented dehydrofelodipine AUC, Cmax, and t1/2 but decreased dehydrofelodipine/felodipine ratios. The AUC of the M3 metabolite and the M3 metabolite/dehydrofelodipine ratios were reduced. These findings support inhibition of both metabolic pathways likely mediated by CYP3A4. Grapefruit juice produced similar mean effects but did not prolong felodipine or dehydrofelodipine t1/2. Individually, felodipine AUC with erythromycin was greater than or similar to that with grapefruit juice. Relative felodipine AUC (erythromycin compared with grapefruit juice) correlated with relative felodipine Cmax but not with relative felodipine t1/2, suggesting felodipine AUC differed between these treatments, mainly from factors affecting presystemic drug elimination. CONCLUSIONS Erythromycin produced an important pharmacokinetic interaction with felodipine by inhibition of drug metabolism. Although erythromycin and grapefruit juice shared a common mechanism, erythromycin likely reduced felodipine biotransformation at the gut wall and liver, whereas single-dose grapefruit juice had an effect mainly at the gut wall.
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Affiliation(s)
- D G Bailey
- Victoria Hospital, University of Western Ontario
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Bailey DG, Arnold JM, Bend JR, Tran LT, Spence JD. Grapefruit juice-felodipine interaction: reproducibility and characterization with the extended release drug formulation. Br J Clin Pharmacol 1995; 40:135-40. [PMID: 8562295 PMCID: PMC1365172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
1. Felodipine 10 mg extended release was administered with 250 ml regular-strength grapefruit juice or water in a randomized crossover manner followed by a second grapefruit juice treatment in 12 healthy men. The pharmacokinetics of felodipine and primary oxidative metabolite, dehydrofelodipine, were evaluated. 2. Initial grapefruit juice treatment increased felodipine AUC (mean +/- s.d.; 56.6 +/- 21.9 vs 28.1 +/- 11.5 ng ml-1 h; P < 0.001) and Cmax (8.1 +/- 2.5 vs 3.3 +/- 1.2 ng ml-1; P < 0.001) compared with water. Felodipine tmax (median; 2.8 vs 3.0 h) and t1/2 (7.3 +/- 3.7 vs 6.9 +/- 3.6 h) were not altered. 3. Readministration of felodipine with grapefruit juice produced mean felodipine AUC (61.5 +/- 32.2 ng ml-1 h) and Cmax (8.4 +/- 4.8 ng ml-1) which were similar to the initial grapefruit juice treatment 1-3 weeks previously. Felodipine AUC (r = 0.73, P < 0.01) and Cmax (r = 0.69, P < 0.02) correlated between grapefruit juice treatments among individuals. 4. The % increase in felodipine AUC with the initial grapefruit juice treatment compared with water correlated with the % increase in felodipine Cmax among individuals (r = 0.80, P < 0.01). Dehydrofelodipine AUC (74.7 +/- 28.7 vs 48.5 +/- 16.3 ng ml-1 h; P < 0.01) and Cmax (12.1 +/- 2.9 vs 7.9 +/- 2.6 ng ml-1; P < 0.01) were augmented with grapefruit juice compared with water.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- D G Bailey
- Victoria Hospital, University of Western Ontario, London, Canada
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