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Liu S, Frye RF, Branch RA, Venkataramanan R, Fung JJ, Burckart GJ. Effect of Age and Postoperative Time on Cytochrome P450 Enzyme Activity Following Liver Transplantation. J Clin Pharmacol 2013; 45:666-73. [PMID: 15901748 DOI: 10.1177/0091270005276202] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
This study evaluates the changes in cytochrome P450 (CYP) enzyme activity in orthotopic liver transplant (OLTx) patients in relation to recipient age and postoperative time. Thirty-eight stable OLTx patients, separated into younger and older age groups, and 21 healthy subjects were given a 5-drug cocktail including chlorzoxazone (CYP2E1), caffeine (CYP1A2), dapsone (CYP3A4), mephenytoin (CYP2C19), and debrisoquin (CYP2D6). The phenotypic indexes were determined for each associated enzyme. Compared to young healthy subjects, the CYP2E1 capacity was significantly increased in younger and older OLTx patients (P < .001), while the CYP2C19 capacity was decreased significantly in younger and older OLTx patients within 30 days postoperatively (P < .01). The CYP2D6 capacity was significantly lower after 30 days postoperatively in older OLTx patients (P < .05). The authors conclude that within 30 days postoperatively, CYP2E1 capacity was markedly elevated in OLTx patients, while 2C19 function was significantly reduced. CYP2D6 capacity was impaired after 30 days postoperatively. Younger and older OLTx patients experienced similar changes in major CYP450 enzyme capacity following liver transplantation.
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Affiliation(s)
- Shanshan Liu
- School of Pharmacy, University of Southern California, 1985 Zonal Ave, PSC 100, Los Angeles, CA 90033, USA
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Karunathilake NP, Frye RF, Stavropoulos MF, Herman MA, Hastie BA. A Preliminary Study on the Effects of Self-Reported Dietary Caffeine on Pain Experience and Postoperative Analgesia. JOURNAL OF CAFFEINE RESEARCH 2012; 2:159-166. [PMID: 24761271 DOI: 10.1089/jcr.2012.0016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
BACKGROUND Caffeine reduces the amount of analgesic medications necessary to provide postoperative pain (POP) relief and augments treatments for headaches and dental pain. Despite considerable evidence of its beneficial effects, little is understood about the role of dietary caffeine consumption on baseline pain sensitivity or POP following oral surgery. METHOD Baseline experimental pain testing (quantitative sensory testing [QST]) using four stimulus modalities was conducted on 30 healthy adults (53% females) before surgical extraction of four third molars. Self-reported caffeine ingestion was reported before QST, and on the day of surgery, preoperative and postoperative caffeine plasma concentrations (CPC) were measured by mass spectrometry. POP ratings were obtained at timed intervals. RESULTS In QST, compared to subjects who self-reported no caffeine intake, those who self-reported caffeine ingestion demonstrated a higher pain sensitivity, particularly, on ramp and hold sustained heat at 44°C and 46°C, as well as a lower heat pain threshold and tolerance (p=0.05). Differences approached significance (p=0.06) in POP between subjects with CPC above 300 ng/mL and those with CPC below 300 ng/mL. Specifically, those with >300 ng/mL CPC had a slightly lower POP (mean 2.43, range 0-5) compared to those with <300 ng/mL CPC whose POP ratings were slightly higher (mean 2.89) with a greater variability (range 0-9.5). CONCLUSIONS Self-reported, dietary caffeine intake was associated with higher QST ratings with lower threshold and tolerance particularly on heat pain modalities. External factors (i.e., analgesic dosage) may have played a role in the analgesic effects of caffeine on POP in oral surgery, especially in individuals with CPC exceeding 300 ng/mL who reported lower pain.
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Affiliation(s)
- Nirmani P Karunathilake
- Community Dentistry & Behavioral Science, College of Dentistry, University of Florida , Gainesville, Florida
| | - Reginald F Frye
- Department of Pharmacotherapy & Translational Research, College of Pharmacy, University of Florida , Gainesville, Florida
| | - Mary F Stavropoulos
- Oral & Maxillofacial Surgery, College of Dentistry, University of Florida , Gainesville, Florida
| | - Mary A Herman
- Department of Anesthesiology, College of Medicine, University of Florida , Gainesville, Florida
| | - Barbara A Hastie
- Community Dentistry & Behavioral Science, College of Dentistry, University of Florida , Gainesville, Florida
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Sachse KT, Jackson EK, Wisniewski SR, Gillespie DG, Puccio AM, Clark RSB, Dixon CE, Kochanek PM. Increases in cerebrospinal fluid caffeine concentration are associated with favorable outcome after severe traumatic brain injury in humans. J Cereb Blood Flow Metab 2008; 28:395-401. [PMID: 17684518 PMCID: PMC3714395 DOI: 10.1038/sj.jcbfm.9600539] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Caffeine, the most widely consumed psychoactive drug and a weak adenosine receptor antagonist, can be neuroprotective or neurotoxic depending on the experimental model or neurologic disorder. However, its contribution to pathophysiology and outcome in traumatic brain injury (TBI) in humans is undefined. We assessed serial cerebrospinal fluid (CSF) concentrations of caffeine and its metabolites (theobromine, paraxanthine, and theophylline) by high-pressure liquid chromatography/ultraviolet in 97 ventricular CSF samples from an established bank, from 30 adults with severe TBI. We prospectively selected a threshold caffeine level of > or = 1 micromol/L (194 ng/mL) as clinically significant. Demographics, Glasgow Coma Scale (GCS) score, admission blood alcohol level, and 6-month dichotomized Glasgow Outcome Scale (GOS) score were assessed. Mean time from injury to initial CSF sampling was 10.77+/-3.13 h. On initial sampling, caffeine was detected in 24 of 30 patients, and the threshold was achieved in 9 patients. Favorable GOS was seen more often in patients with CSF caffeine concentration > or = versus < the threshold (55.6 versus 11.8%, P=0.028). Gender, age, admission CGS score, admission blood alcohol level, and admission systolic arterial blood pressure did not differ between patients with CSF caffeine concentration > or = versus < the threshold. Increases in CSF concentrations of the caffeine metabolites theobromine and paraxanthine were also associated with favorable outcome (P=0.018 and 0.056, respectively). Caffeine and its metabolites are commonly detected in CSF in patients with severe TBI and in an exploratory assessment are associated with favorable outcome. We speculate that caffeine may be neuroprotective by long-term upregulation of adenosine A1 receptors or acute inhibition of A2a receptors.
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Affiliation(s)
- Kathleen T Sachse
- Department of Critical Care Medicine, Safar Center for Resuscitation Research, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15260, USA
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Ohta A, Lukashev D, Jackson EK, Fredholm BB, Sitkovsky M. 1,3,7-trimethylxanthine (caffeine) may exacerbate acute inflammatory liver injury by weakening the physiological immunosuppressive mechanism. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2007; 179:7431-8. [PMID: 18025187 DOI: 10.4049/jimmunol.179.11.7431] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The genetic elimination of A2A adenosine receptors (A2AR) was shown to disengage the critical immunosuppressive mechanism and cause the dramatic exacerbation of acute inflammatory tissue damage by T cells and myeloid cells. This prompted the evaluation of the proinflammatory vs the anti-inflammatory effects of the widely consumed behavioral drug caffeine, as the psychoactive effects of caffeine are mediated largely by its antagonistic action on A2AR in the brain. Because caffeine has other biochemical targets besides A2AR, it was important to test whether the consumption of caffeine during an acute inflammation episode would lead to the exacerbation of immune-mediated tissue damage. We examined acute and chronic treatment with caffeine for its effects on acute liver inflammation. It is shown that caffeine at lower doses (10 and 20 mg/kg) strongly exacerbated acute liver damage and increased levels of proinflammatory cytokines. Because caffeine did not enhance liver damage in A2AR-deficient mice, we suggest that the potentiation of liver inflammation was mediated by interference with the A2AR-mediated tissue-protecting mechanism. In contrast, a high dose of caffeine (100 mg/kg) completely blocked both liver damage and proinflammatory cytokine responses through an A2AR-independent mechanism. Furthermore, caffeine administration exacerbated liver damage even when mice consumed caffeine chronically, although the extent of exacerbation was less than in "naive" mice that did not consume caffeine before. This study suggests an unappreciated "man-made" immunological pathogenesis whereby consumption of the food-, beverage-, and medication-derived adenosine receptor antagonists may modify an individual's inflammatory status and lead to excessive organ damage during acute inflammation.
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Affiliation(s)
- Akio Ohta
- New England Inflammation and Tissue Protection Institute at Northeastern University, Boston, MA 02115, USA.
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O'Connell MB, Frye RF, Matzke GR, St Peter JV, Willhite LA, Welch MR, Kowal P, LaValleur J. Effect of conjugated equine estrogens on oxidative metabolism in middle-aged and elderly postmenopausal women. J Clin Pharmacol 2007; 46:1299-307. [PMID: 17050794 DOI: 10.1177/0091270006292249] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The effects of conjugated equine estrogens (CEE) 0.625 mg daily on cytochrome P450 (CYP) were quantified in 12 middle-aged and 13 elderly postmenopausal women at baseline and 6 months later. CYP phenotype was characterized by caffeine (CYP1A2), chlorzoxazone (CYP2E1), dapsone (CYP, N-acetyltransferase 2), dextromethorphan (CYP2D6), and mephenytoin (CYP2C19) metabolism. CEE significantly decreased CYP1A2 (caffeine metabolic ratio: 0.57 +/- 0.20 before, 0.40 +/- 0.20 after, P = .001) and significantly increased CYP2D6 (dextromethorphan/dextrorphan ratio: 0.0116 +/- 0.0143 before, 0.0084 +/- 0.0135 after, P = .022) metabolism. CEE had no overall effect on CYP2C19, CYP2E1, CYP-mediated dapsone metabolism, and N-acetyltransferase 2. The dextromethorphan metabolic ratio decreased only in the seniors. The dapsone recovery ratio decreased in the middle-aged group and increased in the seniors. CEE significantly influenced CYP1A2, CYP2D6, and CYP-mediated dapsone oxidative metabolism but not CYP2C19, CYP2E1, or N-acetyltransferase 2 metabolism in postmenopausal women. Age influenced CYP2D6 metabolism and dapsone hydroxylation.
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Affiliation(s)
- Mary Beth O'Connell
- Pharmacy Practice Department Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, MI 48201-2427, USA.
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Georga KA, Samanidou VF, Papadoyannis IN. IMPROVED MICRO-METHOD FOR THE HPLC ANALYSIS OF CAFFEINE AND ITS DEMETHYLATED METABOLITES IN HUMAN BIOLOGICAL FLUIDS AFTER SPE. J LIQ CHROMATOGR R T 2006. [DOI: 10.1081/jlc-100100432] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- K. A. Georga
- a Laboratory of Analytical Chemistry, Department of Chemistry , Aristotle University of Thessaloniki , Thessaloniki, GR-54006, Greece
| | - V. F. Samanidou
- a Laboratory of Analytical Chemistry, Department of Chemistry , Aristotle University of Thessaloniki , Thessaloniki, GR-54006, Greece
| | - I. N. Papadoyannis
- a Laboratory of Analytical Chemistry, Department of Chemistry , Aristotle University of Thessaloniki , Thessaloniki, GR-54006, Greece
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Haas CE, Brazeau D, Cloen D, Booker BM, Frerichs V, Zaranek C, Frye RF, Kufel T. Cytochrome P450 mRNA expression in peripheral blood lymphocytes as a predictor of enzyme induction. Eur J Clin Pharmacol 2005; 61:583-93. [PMID: 16041547 DOI: 10.1007/s00228-005-0971-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2005] [Accepted: 06/16/2005] [Indexed: 01/21/2023]
Abstract
OBJECTIVE Previous reports have supported the concept that messenger ribonucleic acid (mRNA) concentrations for cytochrome P450 (CYP) enzymes in peripheral blood mononuclear cells may be predictive of systemic enzyme activity. We investigated whether changes in mRNA expression for CYP1A2,CYP2C19, CYP2D6 and CYP3A4 in peripheral blood lymphocytes (PBLs) may serve as surrogate markers for changes in CYP enzyme activity following the administration of rifampin. METHODS On day 1 and day 9 of the study, 12 healthy volunteers were administered caffeine 100 mg, debrisoquine 10 mg and omeprazole 40 mg orally, along with midazolam 0.025 mg/kg intravenously. Blood samples and urine were collected for 8 h after drug administration. The subjects took rifampin 300 mg (n = 6) or 600 mg (n = 6) daily on days 2-8. Total RNA was isolated from PBLs on day 1 and day 9, and mRNA expression for the CYP enzymes and hGAPDH were determined by means of quantitative, real-time, reverse-transcriptase polymerase chain reaction. CYP1A2 activity was estimated by calculating the plasma paraxanthine to caffeine AUC ratio (caffeine metabolic ratio; CMR), CYP2C19 activity by the 2-h omeprazole hydroxylation index (HI), CYP2D6 activity by the urinary debrisoquine recovery ratio (DBRR) and CYP3A4 activity by midazolam clearance. RESULTS Median midazolam clearance (0.362 to 0.740 l/kg/h), omeprazole HI (0.752 to 0.214), CMR (0.365 to 0.450) and DBRR (0.406 to 0.479) all changed significantly following rifampin, consistent with the expected enzyme induction. CYP1A2,CYP2D6 and CYP3A4 mRNA content were measurable in all samples. CYP2C19 mRNA was inconsistently detectable. There were no significant correlations between changes in enzyme activity and mRNA expression by Spearman's rank order correlation. CONCLUSION The results do not support the use of mRNA expression assays for CYP1A2, CYP2C19, CYP2D6 and CYP3A4 enzymes in PBLs as surrogates for quantifying changes in systemic enzyme activity in the setting of enzyme induction.
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Affiliation(s)
- Curtis E Haas
- School of Pharmacy and Pharmaceutical Sciences, University at Buffalo, 311 Hochstetter Hall, Buffalo, NY 14260, USA.
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Tracy TS, Venkataramanan R, Glover DD, Caritis SN. Temporal changes in drug metabolism (CYP1A2, CYP2D6 and CYP3A Activity) during pregnancy. Am J Obstet Gynecol 2005; 192:633-9. [PMID: 15696014 DOI: 10.1016/j.ajog.2004.08.030] [Citation(s) in RCA: 277] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
OBJECTIVE The purpose of this study was to determine whether drug metabolism (CYP1A2, CYP2D6 and CYP3A) activity varies in the pregnant state compared with the nonpregnant state. STUDY DESIGN Subjects were studied at 14 to18 weeks of gestation, 24 to 28 weeks of gestation, and 36 to 40 weeks of gestation and again at 6 to 8 weeks after the delivery. Twenty-five subjects completed all 4 study periods and had evaluable data. Salivary caffeine clearance was used as a measure of CYP1A2 activity; dextromethorphan O- and N-demethylation were used to assess CYP2D6 and CYP3A activity, respectively. RESULTS CYP1A2 activity was significantly reduced at all periods of the pregnancy as compared with the postpartum period during the first (-32.8% +/- 22.8%), second (-48.1% +/- 27%), and third periods (-65.2% +/- 15.3%), respectively. In contrast, CYP2D6 activity was increased significantly throughout the pregnancy (25.6% +/- 58.3% at 14-18 weeks of gestation, 34.8% +/- 41.4% at 24-28 weeks of gestation, and 47.8% +/- 24.7% at 36-40 weeks of gestation) as compared with the postpartum period. CYP3A activity was consistently, significantly increased (35%-38%) during all stages of the pregnancy. CONCLUSION Opposing changes in drug metabolism occur during pregnancy, with CYP1A2 activity decreased and CYP2D6 and CYP3A activities increased. The direction of dosing adjustments during pregnancy will depend on the drug and the enzyme that is responsible for its metabolism.
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Affiliation(s)
- Timothy S Tracy
- Department of Experimental and Clinical Pharmacology and Center of Excellence in Women's Health, University of Minnesota, Minneapolis, Minn, USA.
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Yin OQP, Lam SSL, Lo CMY, Chow MSS. Rapid determination of five probe drugs and their metabolites in human plasma and urine by liquid chromatography/tandem mass spectrometry: application to cytochrome P450 phenotyping studies. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2004; 18:2921-2933. [PMID: 15529418 DOI: 10.1002/rcm.1704] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
A liquid chromatography/mass spectrometry method, for rapid determination of five cytochrome P450 (CYP) probe drugs and their relevant metabolites in human plasma and urine, is described. The five specific probe substrates/metabolites, caffeine/paraxanthine (CYP1A2), tolbutamide/4-hydroxytolbutamide/carboxytolbutamide (CYP2C9), omeprazole/5-hydroxyomeprazole (CYP2C19), debrisoquine/5-hydroxydebrisoquine (CYP2D6) and midazolam/1'-hydroxymidazolam (CYP3A), together with the internal standards (phenacetin and paracetamol), in plasma and urine, were extracted using solid-phase extraction. The chromatography was performed using a C18 column with an isocratic mobile phase consisting of acetonitrile and 0.1% formic acid in water (70:30). The triple-quadrupole mass spectrometer was operated in both positive and negative modes, and multiple reaction monitoring was used for quantification. The method was validated over the concentration ranges 0.05-5 microg/mL for caffeine and paraxanthine, 0.02-2 microg/mL for tolbutamide, 0.1-20 microg/mL for 4-hydroxytolbutamide, carboxytolbutamide, debrisoquine and 5-hydroxydebrisoquine, 5-2500 ng/mL for omeprazole and 5-hydroxyomeprazole, and 1-100 ng/mL for midazolam and 1'-hydroxymidazolam. The intra- and inter-day precision were 0.3-13.7% and 1.9-14.3%, respectively, and the accuracy ranged from 93.5-107.2%. The lower limit of quantification varied between 1 and 100 ng/mL. The present method provides a robust, fast and sensitive analytical tool for the five-probe drug cocktail, and has been successfully applied to a clinical phenotyping study in 16 subjects.
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Affiliation(s)
- Ophelia Q P Yin
- School of Pharmacy, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong.
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Frye RF, Branch RA. Effect of chronic disulfiram administration on the activities of CYP1A2, CYP2C19, CYP2D6, CYP2E1, and N-acetyltransferase in healthy human subjects. Br J Clin Pharmacol 2002; 53:155-62. [PMID: 11851639 PMCID: PMC1874301 DOI: 10.1046/j.1365-2125.2002.01522.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
AIMS Short-term disulfiram administration has been shown to selectively inhibit CYP2E1 activity but the effects of chronic disulfiram administration on the activities of drug metabolizing enzymes is unclear. The purpose of this study was to evaluate the effects of disulfiram given for 11 days on selected drug metabolizing enzyme activities. METHODS Seven healthy volunteers were given disulfiram 250 mg daily for 11 days. Activities of the drug metabolizing enzymes CYP1A2, CYP2C19, CYP2D6, CYP2E1 and N-acetyltransferase were determined using the probe drugs caffeine, mephenytoin, debrisoquine, chlorzoxazone, and dapsone, respectively. Chlorzoxazone was administered before disulfiram administration and after the second and eleventh doses of disulfiram, while the other probe drugs were given before disulfiram administration and after the eleventh disulfiram dose. RESULTS Disulfiram administration markedly inhibited chlorzoxazone 6-hydroxylation by more than 95%, but did not affect metabolism of debrisoquine or mephenytoin. Caffeine N3-demethylation was decreased by 34% (P < 0.05). Monoacetyldapsone concentrations were markedly elevated by disulfiram administration resulting in a nearly 16-fold increase in the dapsone acetylation index, calculated as the plasma concentration ratio of monoacetyldapsone to dapsone. CYP-mediated dapsone N-hydroxylation was not significantly altered. CONCLUSIONS These data suggest that disulfiram-mediated inhibition is predominantly selective for CYP2E1. The magnitude of CYP2E1 inhibition was similar after both acute and chronic disulfiram administration. The effects on caffeine N3-demethylation (CYP1A2) and dapsone metabolism suggest that chronic disulfiram administration may affect multiple drug metabolizing enzymes, which could potentially complicate the use of chronically administered disulfiram as a diagnostic inhibitor of CYP2E1.
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Affiliation(s)
- Reginald F Frye
- Department of Pharmaceutical Sciences, School of Pharmacy, 807 Salk Hall, University of Pittsburgh, Pittsburgh, PA 15261, USA.
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Georgia KA, Samanidou VF, Papadoyannis IN. Use of novel solid-phase extraction sorbent materials for high-performance liquid chromatography quantitation of caffeine metabolism products methylxanthines and methyluric acids in samples of biological origin. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 2001; 759:209-18. [PMID: 11499474 DOI: 10.1016/s0378-4347(01)00251-1] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
An automated reversed-phase high-performance liquid chromatographic (RP-HPLC) method, using a linear gradient elution, is described for the simultaneous analysis of caffeine and metabolites according to their elution order: 7-methyluric acid, 1-methyluric acid, 7-methylxanthine, 3-methylxanthine, 1-methylxanthine, 1,3-dimethyluric acid, theobromine, 1,7-dimethyluric acid, paraxanthine and theophylline. The analytical column, an MZ Kromasil C4, 250 x 4 mm, 5 microm, was operated at ambient temperature with back pressure values of 80-110 kg/cm2. The mobile phase consisted of an acetate buffer (pH 3.5)-methanol (97:3, v/v) changing to 80:20 v/v in 20 min time, delivered at a flow-rate of 1 ml/min. Paracetamol was used as internal standard at a concentration of 6.18 ng/microl. Detection was performed with a variable wavelength UV-visible detector at 275 nm, resulting in detection limits of 0.3 ng per 10-microl injection, while linearity held up to 8 ng/microl for most of analytes, except for paraxanthine and theophylline, for which it was 12 ng/microl and for caffeine for which it was 20 ng/microl. The statistical evaluation of the method was examined performing intra-day (n=6) and inter-day calibration (n=7) and was found to be satisfactory, with high accuracy and precision results. High extraction recoveries from biological matrices: blood serum and urine ranging from 84.6 to 103.0%, were achieved using Nexus SPE cartridges with hydrophilic and lipophilic properties and methanol-acetate buffer (pH 3.5) (50:50, v/v) as eluent, requiring small volumes, 40 microl of blood serum and 100 microl of urine.
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Affiliation(s)
- K A Georgia
- Department of Chemistry, Aristotle University of Thessaloniki, Greece
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Matzke GR, Frye RF, Early JJ, Straka RJ, Carson SW. Evaluation of the influence of diabetes mellitus on antipyrine metabolism and CYP1A2 and CYP2D6 activity. Pharmacotherapy 2000; 20:182-90. [PMID: 10678296 DOI: 10.1592/phco.20.3.182.34775] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
STUDY OBJECTIVE To evaluate the metabolism of antipyrine, a general metabolic probe, caffeine, a probe for cytochrome P450 (CYP) 1A2 and N-acetyltransferase activity, and dextromethorphan, a specific probe for CYP2D6 activity in patients with type 1 or 2 diabetes mellitus. DESIGN Prospective, controlled study. SETTING Research facility. Patients. Fifteen patients with type 1 and 16 with type 2 diabetes, and 16 healthy controls. INTERVENTION Each subject simultaneously received antipyrine 10 mg/kg, caffeine 100 mg, and dextromethorphan 30 mg. MEASUREMENTS AND MAIN RESULTS The pharmacokinetics of antipyrine and its primary metabolites were determined from saliva and urine samples. Type 1 diabetes had marked effects on antipyrine metabolism whereas type 2 disease did not alter the metabolism of any of the probe drugs. The apparent oral clearance of antipyrine was increased 72% in patients with type 1 disease compared with controls (p=0.0001). In addition, formation clearances of 4-hydroxyantipyrine and 3-hydroxymethylantipyrine were increased by 74% and 137% in those patients relative to controls. The caffeine metabolic index (paraxanthine/caffeine) was increased 34% (p=0.11), and N-acetylation and CYP2D6 phenotype were not altered. CONCLUSION The metabolism of antipyrine is increased in patients with type 1 diabetes. Based on in vitro reports of antipyrine metabolism and current caffeine metabolic index data, the predominant effect of type 1 diabetes appears to be an increase in CYP1A2 activity. Assessment of the effect of the disease on other specific CYP metabolic pathways is warranted.
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Affiliation(s)
- G R Matzke
- Department of Pharmaceutical Sciences, School of Pharmacy, and Center for Clinical Pharmacology, University of Pittsburgh, Pennsylvania 15261, USA
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