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Clinically Relevant Interactions with Anti-Infectives on Intensive Care Units-A Multicenter Delphi Study. Antibiotics (Basel) 2021; 10:antibiotics10111330. [PMID: 34827267 PMCID: PMC8614667 DOI: 10.3390/antibiotics10111330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 10/22/2021] [Accepted: 10/26/2021] [Indexed: 11/23/2022] Open
Abstract
Patients in intensive care units (ICUs) are at high risk of drug–drug interactions (DDIs) due to polypharmacy. Little is known about type and frequency of DDIs within German ICUs. Clinical pharmacists’ interventions (PI) recorded in a national database (ADKA-DokuPIK) were filtered for ICU patients. Binary DDIs involving ≥1 anti-infective agent with >1 database entry were selected. A modified two-step Delphi process with a group of senior hospital pharmacists was employed to evaluate selected DDIs for clinical relevance by using a five-point scale and to develop guidance for clinical practice. In total, 16,173 PI were recorded, including 1836 (11%) DDIs in the ICU setting. Of the latter, 41% (756/1836) included ≥1 anti-infective agent, 32% (590/1836) were binary DDIs, and 25% (455/1836) were listed at least twice. This translates into 88 different DDIs, 74% (65/88) of which were rated as being clinically relevant by our expert panel. The majority of DDIs (76% [67/88]) included macrolides, antifungals, or fluoroquinolones. This percentage was even higher in DDIs being rated as clinically relevant by the experts (85% [55/65]). It is noted that an inter-professional discussion and approach is needed in the individual patient management of DDIs. The guidance developed might be a tool for decision support.
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Yahwak JA, Fraser GL. Early Treatment with Fluconazole in Adult ICU Patients at High Risk for Severe Candidiasis. Hosp Pharm 2017. [DOI: 10.1177/001857870203700903] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
This feature examines the impact of pharmacologic interventions on the treatment of the critically ill patient–an area of health care that has become increasingly complex. It will review recent advances (including evolving and controversial data) in drug therapy for adult ICU patients and assess these new modalities in terms of clinical, humanistic, and economic outcomes.
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Affiliation(s)
- Jason A. Yahwak
- Department of Critical Care, Maine Medical Center, 22 Bramhall Street, Portland, ME 04102
| | - Gilles L. Fraser
- Department of Critical Care, Maine Medical Center, 22 Bramhall Street, Portland, ME 04102
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Bellmann R, Smuszkiewicz P. Pharmacokinetics of antifungal drugs: practical implications for optimized treatment of patients. Infection 2017; 45:737-779. [PMID: 28702763 PMCID: PMC5696449 DOI: 10.1007/s15010-017-1042-z] [Citation(s) in RCA: 203] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Accepted: 06/25/2017] [Indexed: 02/08/2023]
Abstract
Introduction Because of the high mortality of invasive fungal infections (IFIs), appropriate exposure to antifungals appears to be crucial for therapeutic efficacy and safety. Materials and methods This review summarises published pharmacokinetic data on systemically administered antifungals focusing on co-morbidities, target-site penetration, and combination antifungal therapy. Conclusions and discussion Amphotericin B is eliminated unchanged via urine and faeces. Flucytosine and fluconazole display low protein binding and are eliminated by the kidney. Itraconazole, voriconazole, posaconazole and isavuconazole are metabolised in the liver. Azoles are substrates and inhibitors of cytochrome P450 (CYP) isoenzymes and are therefore involved in numerous drug–drug interactions. Anidulafungin is spontaneously degraded in the plasma. Caspofungin and micafungin undergo enzymatic metabolism in the liver, which is independent of CYP. Although several drug–drug interactions occur during caspofungin and micafungin treatment, echinocandins display a lower potential for drug–drug interactions. Flucytosine and azoles penetrate into most of relevant tissues. Amphotericin B accumulates in the liver and in the spleen. Its concentrations in lung and kidney are intermediate and relatively low myocardium and brain. Tissue distribution of echinocandins is similar to that of amphotericin. Combination antifungal therapy is established for cryptococcosis but controversial in other IFIs such as invasive aspergillosis and mucormycosis.
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Affiliation(s)
- Romuald Bellmann
- Clinical Pharmacokinetics Unit, Division of Intensive Care and Emergency Medicine, Department of Internal Medicine I, Medical University of Innsbruck, Anichstrasse 35, 6020, Innsbruck, Austria.
| | - Piotr Smuszkiewicz
- Department of Anesthesiology, Intensive Therapy and Pain Treatment, University Hospital, Poznań, Poland
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Alzghari SK, Seago SE, Cable CT, Herrington JD. Severe palmar-plantar erythrodysesthesia and aplasia in an adult undergoing re-induction treatment with high-dose cytarabine for acute myelogenous leukemia: a possible drug interaction between posaconazole and cytarabine. J Oncol Pharm Pract 2016; 23:476-480. [PMID: 27530244 DOI: 10.1177/1078155216664204] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
High-dose cytarabine is recommended for re-induction chemotherapy in patients less than 60 years of age with acute myelogenous leukemia. This case describes a patient receiving high-dose cytarabine for re-induction and subsequently developed tingling and numbness in her hands and feet followed by severe pain, swelling, and erythema consistent with a diagnosis of palmar-plantar erythrodysesthesia. Furthermore, the patient's hemoglobin, platelets, and neutrophils did not recover after over 30 days post high-dose cytarabine. The patient was concurrently receiving posaconazole for fungal prophylaxis which was initiated after the induction therapy. We speculate that posaconazole may inhibit the cytarabine efflux through P-glycoprotein inhibition leading to the patient's palmar-plantar erythrodysesthesia and subsequent aplasia. Future pharmacokinetic studies need to be conducted to ascertain if posaconazole does influence the pharmacokinetics of cytarabine.
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Zhang S, Pillai VC, Mada SR, Strom S, Venkataramanan R. Effect of voriconazole and other azole antifungal agents on CYP3A activity and metabolism of tacrolimus in human liver microsomes. Xenobiotica 2011; 42:409-16. [PMID: 22106961 DOI: 10.3109/00498254.2011.631224] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Azole antifungal agents are known to inhibit cytochrome P450 3A (CYP3A) enzymes. Limited information is available regarding the effect of voriconazole on CYP3A activity. We examined the effect of voriconazole on CYP3A activity in human liver microsomes as measured by the formation of 6β-hydroxytestosterone from testosterone. We also evaluated the interaction between voriconazole and tacrolimus, an immunosuppressive drug, using human liver microsomes. The effect of voriconazole on CYP3A activity and tacrolimus metabolism was compared to that of other azole antifungal agents. CYP3A4 activity and the metabolism of tacrolimus were measured in the absence and in the presence of various concentrations of voriconazole (0-1.43 mM), fluconazole (0-1.63 mM), itraconazole (0-14 µM) and ketoconazole (0-0.19 µM). At a concentration of 21.2 ± 15.4 µM and 29.8 ± 12.3 µM, voriconazole inhibited the formation of 6β-hydroxytestosterone from testosterone and the metabolism of tacrolimus by 50%, respectively. The rank order of inhibition of 6β-hydroxytestosterone formation from testosterone and the metabolism of tacrolimus, is ketoconazole > itraconazole > voriconazole > fluconazole. Our observations suggest that voriconazole at clinically relevant concentrations will inhibit the hepatic metabolism of tacrolimus and increase the concentration of tacrolimus more than two-fold. Close monitoring of the blood concentrations and adjustment in the dose of tacrolimus are warranted when transplant patients receiving tacrolimus are treated with voriconazole.
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Affiliation(s)
- Shimin Zhang
- Department of Pharmaceutical Sciences, University of Pittsburgh, Pittsburgh, PA 15261, USA
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Bellmann R, Weiler S. Treatment of invasive fungal infections. MEMO-MAGAZINE OF EUROPEAN MEDICAL ONCOLOGY 2011. [DOI: 10.1007/s12254-011-0290-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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Abstract
Blastomycosis is endemic in regions of North America that border the Great Lakes and the St. Lawrence River, as well as in the Mississippi River and Ohio River basins. Men are affected more often than women and children because men are more likely to participate in activities that put them at risk for exposure to Blastomyces dermatitidis. Human infection occurs when soil containing microfoci of mycelia is disturbed and airborne conidia are inhaled. If natural defenses in the alveoli fail to contain the infection, lymphohematogenous dissemination ensues. Normal host responses generate a characteristic pyogranulomatous reaction. The most common sites of clinical disease are the lung and skin; osseous, genitourinary, and central nervous system manifestations follow in decreasing order of frequency. Blastomycosis is one of the great mimickers in medicine; verrucous cutaneous blastomycosis resembles malignancy, and mass-like lung opacities due to B. dermatitidis often are confused with cancer. Blastomycosis may be clinically indistinguishable from tuberculosis. Diagnosis is based on culture and direct visualization of round, multinucleated yeast forms that produce daughter cells from a single broad-based bud. Although a long course of amphotericin B is usually curative, itraconazole is also highly effective and is the mainstay of therapy for most patients with blastomycosis.
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Kohno S, Masaoka T, Yamaguchi H, Mori T, Urabe A, Ito A, Niki Y, Ikemoto H. A Multicenter, Open-Label Clinical Study of Micafungin (FK463) in the Treatment of Deep-seated Mycosis in Japan. ACTA ACUST UNITED AC 2009; 36:372-9. [PMID: 15287383 DOI: 10.1080/00365540410020406] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The efficacy and safety of micafungin (FK463), which is a new lipopeptide antifungal agent of the echinocandin class and is active against both Aspergillus and Candida species, were investigated in patients with deep-seated mycosis in this study. 70 patients were treated with micafungin 12.5-150 mg/d intravenously for up to 56 d. The overall clinical response rates were 60% (6/10) in invasive pulmonary aspergillosis, 67% (6/9) in chronic necrotizing pulmonary aspergillosis, 55% (12/22) in pulmonary aspergilloma, 100% (6/6) in candidemia, and 71% (5/7) in esophageal candidiasis. The response rates for patients with prior antifungal treatment which was considered ineffective or toxic, were similar to rates for patients without prior treatment. Mycological eradication was observed in patients infected with Aspergillus fumigatus, Aspergillus flavus, Aspergillus terreus, Aspergillus niger, Candida albicans, Candida glabrata, or Candida krusei. Adverse events related to micafungin were reported in 21 patients (30%), and there was no dose-related occurrence of any adverse event. It is concluded that treatment with micafungin as monotherapy seems to be effective and safe in patients with deep-seated mycosis.
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Affiliation(s)
- Shigeru Kohno
- Section of Molecular and Clinical Microbiology, Department of Microbiology and Immunology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
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Gubbins PO, Amsden JR. Drug-drug interactions of antifungal agents and implications for patient care. Expert Opin Pharmacother 2007; 6:2231-43. [PMID: 16218884 DOI: 10.1517/14656566.6.13.2231] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Drug interactions in the gastrointestinal tract, liver and kidneys result from alterations in pH, ionic complexation, and interference with membrane transport proteins and enzymatic processes involved in intestinal absorption, enteric and hepatic metabolism, renal filtration and excretion. Azole antifungals can be involved in drug interactions at all the sites, by one or more of the above mechanisms. Consequently, azoles interact with a vast array of compounds. Drug-drug interactions associated with amphotericin B formulations are predictable and result from the renal toxicity and electrolyte disturbances associated with these compounds. The echinocandins are unknown cytochrome P450 substrates and to date are relatively devoid of significant drug-drug interactions. This article reviews drug interactions involving antifungal agents that affect other agents and implications for patient care are highlighted.
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Affiliation(s)
- Paul O Gubbins
- Department of Pharmacy Practice, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
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Irani S, Fattinger K, Schmid-Mahler C, Achermann E, Speich R, Boehler A. Blood Concentration Curve of Cyclosporine: Impact of Itraconazole in Lung Transplant Recipients. Transplantation 2007; 83:1130-3. [PMID: 17452906 DOI: 10.1097/01.tp.0000259724.44008.9d] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Although the influence of cytochrome P450 inhibitory drugs on the area under the curve (AUC) of cyclosporine (CsA) has been described, data concerning the impact of these substances on the shape of the blood concentration curve are scarce. By assessment of CsA blood levels before and 1, 2, and 4 hr after oral intake (C0, C1, C2, and C4, respectively) CsA profiling examinations were performed in 20 lung transplant recipients taking 400 mg, 200 mg, and no itraconazole, respectively. The three groups showed comparable results for C0, C2, and AUC(0-12). Greater values were found for Cmax, Cmax-C0, peak-trough fluctuation and rise to Cmax in favor of the non-itraconazole group. Additionally, tmax was shorter in the non-itraconazole group. Comedication with the metabolic inhibitor itraconazole is associated with a flattening of the CsA blood concentration profile in lung transplant recipients. These changes cannot be assessed by isolated C0, C2, or AUC(0-12) values alone.
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Affiliation(s)
- Sarosh Irani
- Clinic of Pulmonary Medicine, University Hospital Zurich, Zurich, Switzerland
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12
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Saad AH, DePestel DD, Carver PL. Factors Influencing the Magnitude and Clinical Significance of Drug Interactions Between Azole Antifungals and Select Immunosuppressants. Pharmacotherapy 2006; 26:1730-44. [PMID: 17125435 DOI: 10.1592/phco.26.12.1730] [Citation(s) in RCA: 212] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The magnitude of drug interactions between azole antifungals and immunosuppressants is drug and patient specific and depends on the potency of the azole inhibitor involved, the resulting plasma concentrations of each drug, the drug formulation, and interpatient variability. Many factors contribute to variability in the magnitude and clinical significance of drug interactions between an immunosuppressant such as cyclosporine, tacrolimus, or sirolimus and an antifungal agent such as ketoconazole, fluconazole, itraconazole, voriconazole, or posaconazole. By bringing similarities and differences among these agents and their potential interactions to clinicians' attention, they can appreciate and apply these findings in a individualized patient approach rather than follow only the one-size-fits-all dosing recommendations suggested in many tertiary references. Differences in metabolism and in the inhibitory potency of cytochrome P450 3A4 and P-glycoprotein influence the onset, magnitude, and resolution of drug interactions and their potential effect on clinical outcomes. Important issues are the route of administration and the decision to preemptively adjust dosages versus intensive monitoring with subsequent dosage adjustments. We provide recommendations for the concomitant use of these agents, including suggestions regarding contraindicated combinations, those best avoided, and those requiring close monitoring of drug dosages and plasma concentrations.
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Affiliation(s)
- Aline H Saad
- Department of Pharmacy Services, University of Michigan Health System, Ann Arbor, Michigan 48109-1065, USA
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Shakeri-Nejad K, Stahlmann R. Drug interactions during therapy with three major groups of antimicrobial agents. Expert Opin Pharmacother 2006; 7:639-51. [PMID: 16556082 DOI: 10.1517/14656566.7.6.639] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
This review focuses on drug-drug interactions with three major groups of antimicrobial agents: macrolides (including azalides and ketolides), quinolones, which are widely used for the treatment of bacterial infections, and azoles, which are used for antifungal therapy. Macrolides and the ketolide telithromycin are potent inhibitors of CYP3A4 and thus interfere with the pharmacokinetics of many other drugs that are metabolised by this enzyme. In contrast, although closely related, azithromycin is not a cytochrome inhibitor. All quinolones form complexes with di- and trivalent cations and, therefore, the absorption of quinolones can be dramatically reduced when given concomitantly with mineral antacids, zinc or iron preparations. Ciprofloxacin exhibits an inhibitory potential for the cytochrome isoenzyme 1A2, resulting in an inhibition of theophylline metabolism. Other quinolones, such as levofloxacin or moxifloxacin, do not interfere with theophylline metabolism. The systemic azoles, such as ketoconazole, itraconazole, fluconazole and voriconazole, are inhibitors of CYP isoenzymes, such as CYP3A4, CYP2C9 and CYP2C19, to varying degrees. In addition, some are substrates of the MDR-1 gene product, P-glycoprotein. These features are the basis for most of the interactions occurring during azole therapy (e.g., in severely ill patients in the hospital who are treated with multiple drugs).
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Affiliation(s)
- Kasra Shakeri-Nejad
- PAREXEL International GmbH, Institute of Clinical Pharmacology, Clinical Operations, Spandauer Damm 130, Haus 18, 14050 Berlin, Germany
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Gupta AK, Kogan N, Batra R. Pityriasis versicolor: a review of pharmacological treatment options. Expert Opin Pharmacother 2006; 6:165-78. [PMID: 15757415 DOI: 10.1517/14656566.6.2.165] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Pityriasis versicolor is a common disorder of the skin, which is characterised by scaly hypo- or hyperpigmented lesions on the body. The lipophilic yeast, Malassezia, is considered to be the aetiological agent of this disease. A number of treatment options, both topical and systemic, have been shown to be effective. A critical evaluation of treatment options is presented.
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Affiliation(s)
- Aditya K Gupta
- University of Toronto, and the Sunnybrook and Womens' College Health Sciences Center (Sunnybrook site), Toronto, Ontario, Canada.
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Yu DT, Peterson JF, Seger DL, Gerth WC, Bates DW. Frequency of potential azole drug-drug interactions and consequences of potential fluconazole drug interactions. Pharmacoepidemiol Drug Saf 2005; 14:755-67. [PMID: 15654717 DOI: 10.1002/pds.1073] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To assess the frequency of potential azole-drug interactions and consequences of interactions between fluconazole and other drugs in routine inpatient care. METHODS We performed a retrospective cohort study of hospitalized patients treated for systemic fungal infections with an oral or intravenous azole medication between July 1997 and June 2001 in a tertiary care hospital. We recorded the concomitant use of medications known to interact with azole antifungals and measured the frequency of potential azole drug interactions, which we considered to be present when both drugs were given together. We then performed a chart review on a random sample of admissions in which patients were exposed to a potential moderate or major drug interaction with fluconazole. The list of azole-interacting medications and the severity of interaction were derived from the DRUGDEX System and Drug Interaction Facts. RESULTS Among the 4,185 admissions in which azole agents (fluconazole, itraconazole or ketoconazole) were given, 2,941 (70.3%) admissions experienced potential azole-drug interactions, which included 2,716 (92.3%) admissions experiencing potential fluconazole interactions. The most frequent interactions with potential moderate to major severity were co-administration of fluconazole with prednisone (25.3%), midazolam (17.5%), warfarin (14.7%), methylprednisolone (14.1%), cyclosporine (10.7%) and nifedipine (10.1%). Charts were reviewed for 199 admissions in which patients were exposed to potential fluconazole drug interactions. While four adverse drug events (ADEs) caused by fluconazole were found, none was felt to be caused by a drug-drug interaction (DDI), although in one instance fluconazole may have contributed. CONCLUSIONS Potential fluconazole drug interactions were very frequent among hospitalized patients on systemic azole antifungal therapy, but they had few apparent clinical consequences.
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Affiliation(s)
- D Tony Yu
- Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Division of General Medicine, Boston, MA, USA
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Fernandez-Obregon AC, Rohrback J, Reichel MA, Willis C. Current use of anti-infectives in dermatology. Expert Rev Anti Infect Ther 2005; 3:557-91. [PMID: 16107197 DOI: 10.1586/14787210.3.4.557] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Dermatologic diseases encompass a broad category of pathologic situations. Infection remains a significant aspect of the pathology faced in patient encounters, and it is natural to expect that anti-infectives play a major element in the armamentarium utilized by dermatologists. Aside from the treatment of the classic bacterial and fungal infections, there are now new uses for antiviral agents to help suppress recurrent disease, such as herpes simplex. There is also the novel approach of using anti-infectives, or agents that have been thought to have antimicrobial activity, to treat inflammatory diseases. This review describes anti-infectives, beginning with common antibiotics used to treat bacterial infections. The discussion will then cover the current use of antivirals. Finally, the description of antifungals will be separated, starting with the oral agents and ending with the topical antimycotics. The use of anti-infectives in tropical dermatology has been purposefully left out, and perhaps should be the subject of a separate review. Cutaneous bacterial infections consist chiefly of those microorganisms that colonize the skin, such as species of staphylococcus and streptococcus. Propionibacterium acnes and certain other anaerobes can be involved in folliculitis, pyodermas and in chronic conditions such as hidradenitis suppurativa.
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Park JY, Kim KA, Shin JG, Lee KY. Effect of ketoconazole on the pharmacokinetics of rosiglitazone in healthy subjects. Br J Clin Pharmacol 2005; 58:397-402. [PMID: 15373932 PMCID: PMC1884597 DOI: 10.1111/j.1365-2125.2004.02161.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
AIMS Fungal infection is a significant comorbidity in patients with diabetes mellitus, and ketoconazole, an antifungal agent, causes a number of drug interactions with coadministered drugs. Rosiglitazone is a novel thiazolidinedione antidiabetic drug, mainly metabolized by CYP2C8 and to a lesser extent CYP2C9. We investigated the possible effect of ketoconazole on the pharmacokinetics of rosiglitazone in humans. METHODS Ten healthy Korean male volunteers were treated twice daily for 5 days with 200 mg ketoconazole or with placebo, using a randomized, open-label, two-way crossover study. On day 5, a single dose of 8 mg rosiglitazone was administered orally, and plasma rosiglitazone concentrations were measured. RESULTS Ketoconazole increased the mean area under the plasma concentration-time curve for rosiglitazone by 47%[P = 0.0003; 95% confidence interval (CI) 23, 70] and the mean elimination half-life from 3.55 to 5.50 h (P = 0.0003; 95% CI in difference 1.1, 2.4). The peak plasma concentration of rosiglitazone was increased by ketoconazole treatment by 17% (P = 0.03; 95% CI 5, 29). The apparent oral clearance of rosiglitazone decreased by 28% after ketoconazole treatment (P = 0.0005; 95% CI 18, 38). CONCLUSIONS This study revealed that ketoconazole affected the disposition of rosiglitazone in humans, probably by the inhibition of CYP2C8 and CYP2C9, leading to increasing rosiglitazone concentrations that could increase the efficacy of rosiglitazone or its adverse events.
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Affiliation(s)
- Ji-Young Park
- Department of Pharmacology, Gachon Medical School and Clinical Trial Centre, Gil Medical Centre, Incheon, Korea.
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Fradette C, Yamaguchi N, du Souich P. 5-Hydroxytryptamine is biotransformed by CYP2C9, 2C19 and 2B6 to hydroxylamine, which is converted into nitric oxide. Br J Pharmacol 2004; 141:407-14. [PMID: 14718257 PMCID: PMC1574215 DOI: 10.1038/sj.bjp.0705632] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
There is circumstantial evidence suggesting that 5-hydroxytryptamine (5-HT) could be biotransformed by enzymatic systems other than monoamino oxidase A, and that the isoforms of cytochrome P450 may be a source of nitric oxide. This study aimed to assess whether cytochrome P450 contributes to 5-HT biotransformation, and to provide evidence that 5-HT metabolism generates nitric oxide. Addition of 5-HT to cultured hepatocytes yielded 5-hydroxyindol acetic acid, a formation modulated by cytochrome P450 enzyme inducers and inhibitors. Recombinant human CYP2B6, 2C9 and 2C19 biotransformed 5-HT in 5-hydroxyindol acetic acid, but not CYP1A2, 2D6 or 3A4. Cultured hepatocytes with 5-HT generated nitric oxide, the amount of which was altered by cytochrome P450 enzyme inducers and inhibitors. In the presence of CYP2B6, 2C9 and 2C19, 5-HT relaxed precontracted isolated aortic rings, with or without endothelium, an effect prevented by the addition of methylene blue and an inhibitor of catalase, but not by myoglobin. In the absence of catalase, hydroxylamine was always assayed as a byproduct of 5-HT metabolism. In conclusion, CYP2B6, 2C9 and 2C19 biotransform 5-HT, yielding hydroxylamine, which is converted to nitric oxide in the presence of catalase. British Journal of Pharmacology (2004) 141, 407-414. doi:10.1038/sj.bjp.0705632
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Affiliation(s)
- Caroline Fradette
- Department of Pharmacology, Faculty of Medicine, University of Montréal, P.O. Box 6128, Stat. Centre-Ville, Montréal, Québec, Canada H3C 3J7
| | - Nobuharu Yamaguchi
- Faculty of Pharmacy, University of Montréal, P.O. Box 6128, Stat. Centre-Ville, Montréal, Québec, Canada H3C 3J7
| | - Patrick du Souich
- Department of Pharmacology, Faculty of Medicine, University of Montréal, P.O. Box 6128, Stat. Centre-Ville, Montréal, Québec, Canada H3C 3J7
- Author for correspondence:
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Panomvana Na Ayudhya D, Thanompuangseree N, Tansuphaswadikul S. Effect of Rifampicin on the Pharmacokinetics of Fluconazole in Patients with AIDS. Clin Pharmacokinet 2004; 43:725-32. [PMID: 15301576 DOI: 10.2165/00003088-200443110-00003] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
OBJECTIVE To study the effect of rifampicin on the pharmacokinetics of fluconazole and on clinical outcomes of fluconazole treatment in patients with AIDS-related cryptococcal meningitis. PATIENTS Forty Thai patients with AIDS and cryptococcal meningitis, of whom 20 had been receiving oral rifampicin for at least 2 weeks to treat tuberculosis. METHODS Patients were treated for cryptococcal meningitis with amphotericin 0.7 mg/kg/day for 14 days followed by fluconazole 400 mg/day, which was reduced to 200 mg/day once culture of cerebrospinal fluid (CSF) became negative. Patients with tuberculosis received oral rifampicin 600 mg/day at night. Blood samples were collected from the first 12 patients in each group and pharmacokinetic parameters for fluconazole were calculated. CSF samples were collected by lumbar puncture and monitored for eradication of Cryptococcus neoformans. RESULTS Concomitant administration of rifampicin with fluconazole resulted in significant changes in the pharmacokinetic parameters of fluconazole, including a 39% increase in elimination rate constant, 28% shorter elimination half-life, 22% decrease in area under the concentration-time curve, 17% decrease in maximum concentration and 30% increase in clearance (p < 0.05). Different fluconazole regimens did not affect the extent of change in the elimination rate constant. Although serum concentrations of fluconazole during the time that patients received rifampicin concomitantly with fluconazole 200 mg/day were generally lower than the minimum inhibitory concentration for C. neoformans, there were no significant differences in clinical outcomes between the two groups to date (p = 0.792). CONCLUSIONS Coadministration of rifampicin with fluconazole caused significant changes in the pharmacokinetic parameters of fluconazole. Long-term monitoring for recurrence rates of cryptococcal meningitis is required to assess the clinical significance of this interaction.
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Slavik RS, Jewesson PJ. Selecting antibacterials for outpatient parenteral antimicrobial therapy : pharmacokinetic-pharmacodynamic considerations. Clin Pharmacokinet 2003; 42:793-817. [PMID: 12882587 DOI: 10.2165/00003088-200342090-00002] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Some infectious diseases require management with parenteral therapy, although the patient may not need hospitalisation. Consequently, the administration of intravenous antimicrobials in a home or infusion clinic setting has now become commonplace. Outpatient parenteral antimicrobial therapy (OPAT) is considered safe, therapeutically effective and economical. A broad range of infections can be successfully managed with OPAT, although this form of treatment is unnecessary when oral therapy can be used. Many antimicrobials can be employed for OPAT and the choice of agent(s) and regimen should be based upon sound clinical and microbiological evidence. Assessments of cost and convenience should be made subsequent to these primary treatment outcome determinants. When designing an OPAT treatment regimen, the pharmacokinetic and pharmacodynamic characteristics of the individual agents should also be considered. Pharmacokinetics (PK) is the study of the time course of absorption, distribution, metabolism and elimination of drugs (what the body does to the drug). Clinical pharmacokinetic monitoring has been used to overcome the pharmacokinetic variability of antimicrobials and enable individualised dosing regimens that attain desirable antimicrobial serum concentrations. Pharmacodynamics (PD) is the study of the relationship between the serum concentration of a drug and the clinical response observed in a patient (what the drug does to the body). By combining pharmacokinetic properties (peak [C(max)] or trough [C(min)] serum concentrations, half-life, area under the curve) and pharmacodynamic properties (susceptibility results, minimum inhibitory concentrations [MIC] or minimum bactericidal concentrations [MBC], bactericidal or bacteriostatic killing, post-antibiotic effects), unique PK/PD parameters or indices (t > MIC, C(max)/MIC, AUC(24)/MIC) can be defined. Depending on the killing characteristics of a given class of antimicrobials (concentration-dependent or time-dependent), specific PK/PD parameters may predict in vitro bacterial eradication rates and correlate with in vivo microbiologic and clinical cures. An understanding of these principles will enable the clinician to vary dosing schemes and design individualised dosing regimens to achieve optimal PK/PD parameters and potentially improve patient outcomes. This paper will review basic principles of useful PK/PD parameters for various classes of antimicrobials as they may relate to OPAT. In summary, OPAT has become an important treatment option for the management of infectious diseases in the community setting. To optimise treatment course outcomes, pharmacokinetic and pharmacodynamic properties of the individual agents should be carefully considered when designing OPAT treatment regimens.
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Affiliation(s)
- Richard S Slavik
- Clinical Service Unit Pharmaceutical Sciences, Vancouver Hospital and Health Sciences Centre, and Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia, Canada
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Crouch MA, Limon L, Cassano AT. Clinical relevance and management of drug-related QT interval prolongation. Pharmacotherapy 2003; 23:881-908. [PMID: 12885102 DOI: 10.1592/phco.23.7.881.32730] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Much attention recently has focused on drugs that prolong the QT interval, potentially leading to fatal cardiac dysrhythmias (e.g., torsade de pointes). We provide a detailed review of the published evidence that supports or does not support an association between drugs and their risk of QT prolongation. The mechanism of drug-induced QT prolongation is reviewed briefly, followed by an extensive evaluation of drugs associated with QT prolongation, torsade de pointes, or both. Drugs associated with QT prolongation are identified as having definite, probable, or proposed associations. The role of the clinician in the prevention and management of QT prolongation, drug-drug interactions that may occur with agents known to affect the QT interval, and the impact of this adverse effect on the regulatory process are addressed.
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Affiliation(s)
- Michael A Crouch
- Department of Pharmacy, Virginia Commonwealth University, Medical College of Virginia, Richmond, Virginia 23298-0533, USA.
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Venkataramanan R, Zang S, Gayowski T, Singh N. Voriconazole inhibition of the metabolism of tacrolimus in a liver transplant recipient and in human liver microsomes. Antimicrob Agents Chemother 2002; 46:3091-3. [PMID: 12183280 PMCID: PMC127452 DOI: 10.1128/aac.46.9.3091-3093.2002] [Citation(s) in RCA: 116] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The purpose of this study was to assess the effect of voriconazole on the blood tacrolimus concentration in a liver transplant recipient and to examine the interaction between voriconazole and tacrolimus by using human liver microsomes. Two subjects were enrolled in the clinical study: one received voriconazole, and the other received a placebo. Tacrolimus metabolism was evaluated in human liver microsomes at various concentrations in the absence and presence of various concentrations of voriconazole. Coadministration of voriconazole and tacrolimus resulted in elevated (nearly 10-fold-higher) trough tacrolimus blood concentrations in the liver transplant patient. In the in vitro study, voriconazole at a concentration of 10.4 +/- 4.3 micro g/ml inhibited the metabolism of tacrolimus by 50%. Clinically relevant concentrations of voriconazole inhibited the metabolism of tacrolimus in human liver microsomes. Close monitoring of the blood concentration and adjustment in the dose of tacrolimus are warranted in transplant recipients treated with voriconazole.
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Affiliation(s)
- Raman Venkataramanan
- School of Pharmacy, University of Pittsburgh, and Veterans Affairs Medical Center, Pittsburgh, Pennsylvania 15240, USA
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23
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Georgopapadakou NH. Antifungals targeted to protein modification: focus on protein N-myristoyltransferase. Expert Opin Investig Drugs 2002; 11:1117-25. [PMID: 12150705 DOI: 10.1517/13543784.11.8.1117] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Invasive fungal infections have increased dramatically in recent years to become important causes of morbidity and mortality in hospitalised patients. Currently available antifungal drugs for such infections essentially have three molecular targets: 14 alpha demethylase (azoles), ergosterol (polyenes) and beta-1,3-glucan synthase (echinocandins). The first is a fungistatic target vulnerable to resistance development; the second, while a fungicidal target, is not sufficiently different from the host to ensure high selectivity; the third, a fungistatic (Aspergillus) or fungicidal (Candida) target, has limited activity spectrum (gaps: Cryptococcus, emerging fungi) and potential host toxicity that might preclude dose escalation. Drugs aimed at totally new targets are thus needed to increase our chemotherapeutic options and to forestall, alone or in combination chemotherapy, the emergence of drug resistance. Protein N-myristoylation, the cotranslational transfer of the 14-carbon saturated fatty acid myristate from CoA to the amino-terminal glycine of several fungal proteins such as the ADP-ribosylation factor (ARF), presents such an attractive new target. The reaction, catalysed by myristoyl-CoA:protein N-myristoyltransferase (NMT), is essential for viability, is biochemically tractable and has proven potential for selectivity. In the past five years, a number of selective inhibitors of the fungal enzyme, some with potent, broad spectrum antifungal activity, have been reported: myristate analogues, myristoylpeptide derivatives, histidine analogues (peptidomimetics), aminobenzothiazoles, quinolines and benzofurans. A major development has been the publication of the crystal structure of Candida albicans and Saccharomyces cerevisiae NMTs, which has allowed virtual docking of inhibitors on the enzyme and refinement of structure-activity relationships of lead compounds.
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Abstract
In 1992, the Food and Drug Administration (FDA) issued new guidelines governing stereoisomerism in new-drug development. The guidelines strongly encourage the development of single isomers and discourage stereoisomeric (eg, racemic) mixtures. As a result, most new chiral drugs are being developed as single enantiomers (ie, single isomers). There are three mechanisms for the identification and development of new single-isomer drugs: chiral switches (CS), chiral metashifts (CM), and new single-isomer chemical entities (NSICEs). In a CS, one of the two enantiomers of an established racemate is developed as a new drug, with the expectation that the single-isomer form has advantages over the racemic parent in terms of efficacy and/or adverse effects. Many new CS drugs are in development, eg, (S)-oxybutynin for urinary incontinence and escitalopram for depression. In a CM, a chiral metabolite of a drug is developed, in single-isomer form, as an agent with advantages over the parent. Among the current CM drugs in development are (+)-norcisapride (safer GI prokinetic agent than the racemic parent cisapride) and (S)-desmethylzopiclone (antianxiety agent, metabolite of the sedative-hypnotic zopiclone). Many NSICEs are in development, eg, rosuvastatin as an antihypercholesterolemic, posaconazole as an antifungal, sitafloxacin as a fluoroquinolone antibacterial, pregabalin as an anticonvulsant, abarelix as an antineoplastic, etc. As in the development of any new drug, not every single-isomer candidate will reach the clinic, but there is no doubt that the move to single-isomer agents is an important step forward in the search for better and safer drugs.
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Affiliation(s)
- Joseph Gal
- Division of Clinical Pharmacology, University of Colorado School of Medicine, Denver, Colorado, USA
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Pea F, Furlanut M. Pharmacokinetic aspects of treating infections in the intensive care unit: focus on drug interactions. Clin Pharmacokinet 2002; 40:833-68. [PMID: 11735605 DOI: 10.2165/00003088-200140110-00004] [Citation(s) in RCA: 112] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Pharmacokinetic interactions involving anti-infective drugs may be important in the intensive care unit (ICU). Although some interactions involve absorption or distribution, the most clinically relevant interactions during anti-infective treatment involve the elimination phase. Cytochrome P450 (CYP) 1A2, 2C9, 2C19, 2D6 and 3A4 are the major isoforms responsible for oxidative metabolism of drugs. Macrolides (especially troleandomycin and erythromycin versus CYP3A4), fluoroquinolones (especially enoxacin, ciprofloxacin and norfloxacin versus CYP1A2) and azole antifungals (especially fluconazole versus CYP2C9 and CYP2C19, and ketoconazole and itraconazole versus CYP3A4) are all inhibitors of CYP-mediated metabolism and may therefore be responsible for toxicity of other coadministered drugs by decreasing their clearance. On the other hand, rifampicin is a nonspecific inducer of CYP-mediated metabolism (especially of CYP2C9, CYP2C19 and CYP3A4) and may therefore cause therapeutic failure of other coadministered drugs by increasing their clearance. Drugs frequently used in the ICU that are at risk of clinically relevant pharrmacokinetic interactions with anti-infective agents include some benzodiazepines (especially midazolam and triazolam), immunosuppressive agents (cyclosporin, tacrolimus), antiasthmatic agents (theophylline), opioid analgesics (alfentanil), anticonvulsants (phenytoin, carbamazepine), calcium antagonists (verapamil, nifedipine, felodipine) and anticoagulants (warfarin). Some lipophilic anti-infective agents inhibit (clarithromycin, itraconazole) or induce (rifampicin) the transmembrane transporter P-glycoprotein, which promotes excretion from renal tubular and intestinal cells. This results in a decrease or increase, respectively, in the clearance of P-glycoprotein substrates at the renal level and an increase or decrease, respectively, of their oral bioavailability at the intestinal level. Hydrophilic anti-infective agents are often eliminated unchanged by renal glomerular filtration and tubular secretion, and are therefore involved in competition for excretion. Beta-lactams are known to compete with other drugs for renal tubular secretion mediated by the organic anion transport system, but this is frequently not of major concern, given their wide therapeutic index. However, there is a risk of nephrotoxicity and neurotoxicity with some cephalosporins and carbapenems. Therapeutic failure with these hydrophilic compounds may be due to haemodynamically active coadministered drugs, such as dopamine, dobutamine and furosemide, which increase their renal clearance by means of enhanced cardiac output and/or renal blood flow. Therefore, coadministration of some drugs should be avoided, or at least careful therapeutic drug monitoring should be performed when available. Monitoring may be especially helpful when there is some coexisting pathophysiological condition affecting drug disposition, for example malabsorption or marked instability of the systemic circulation or of renal or hepatic function.
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Affiliation(s)
- F Pea
- Institute of Clinical Pharmacology and Toxicology, Department of Experimental and Clinical Pathology and Medicine, Medical School, University of Udine, Italy.
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Damle B, Hess H, Kaul S, Knupp C. Absence of clinically relevant drug interactions following simultaneous administration of didanosine-encapsulated, enteric-coated bead formulation with either itraconazole or fluconazole. Biopharm Drug Dispos 2002; 23:59-66. [PMID: 11932960 DOI: 10.1002/bdd.296] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
This open-label, two-way crossover study was undertaken to determine whether the enteric formulation of didanosine influences the pharmacokinetics of itraconazole or fluconazole, two agents frequently used to treat fungal infections that occur with HIV infection, and whose bioavailability may be influenced by changes in gastric pH. Healthy subjects were randomized to Treatment A (200-mg itraconazole or 200-mg fluconazole) or Treatment B (same dose of itraconazole or fluconazole with 400 mg of didanosine as an encapsulated, enteric-coated bead formulation). In the itraconazole study, a lack of interaction was concluded if the 90% confidence interval (CI) of the ratio of the geometric means of log-transformed C(max) and AUC(0-T) values of itraconazole and hydroxyitraconazole, the active metabolite of itraconazole, were contained entirely between 0.75 and 1.33. In the fluconazole study, the equivalence interval for C(max) and AUC(0-T) was 0.80-1.25. The data showed that for itraconazole the point estimate and 90% CI of the ratios of C(max) and AUC(0-T) values were 0.98 (0.79, 1.20) and 0.88 (0.71, 1.09), respectively; for hydroxyitraconazole the respective values were 0.91 (0.76, 1.08) and 0.85 (0.68, 1.06). In the fluconazole study, the point estimate and 90% CI of the ratios of C(max) and AUC(0-T) values were 0.98 (0.93, 1.03) and 1.01 (0.99, 1.03), respectively. The T(max) for itraconazole, hydroxyitraconazole, and fluconazole were similar between treatments. Both studies indicated a lack of clinically significant interactions of the didanosine formulation with itraconazole or fluconazole. These results showed that the encapsulated, enteric-coated bead formulation of didanosine can be concomitantly administered with drugs, such as the azole antifungal agents, whose bioavailability may be influenced by interaction with antacids.
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Affiliation(s)
- B Damle
- Clinical Discovery, Bristol-Myers Squibb Pharmaceutical Research Institute, Princeton, NJ 08543, USA.
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Abstract
A 60-year-old man with advanced gastric cancer achieved good pain control on a stable dose of methadone for 10 days. However, he developed respiratory depression 2 days after intravenous fluconazole was administrated for refractory oral candidiasis. Intravenous naloxone effectively reversed the respiratory depression. This case illustrates a significant interaction between methadone and fluconazole, and highlights the need for awareness of potential interactions between drugs used in palliative care.
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Affiliation(s)
- Yoko Tarumi
- Palliative Care Program, Grey Nuns Community Hospital, Edmonton, Alberta, Canada
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Kuroha M, Azumano A, Kuze Y, Shimoda M, Kokue E. Effect of multiple dosing of ketoconazole on pharmacokinetics of midazolam, a cytochrome P-450 3A substrate in beagle dogs. Drug Metab Dispos 2002; 30:63-8. [PMID: 11744613 DOI: 10.1124/dmd.30.1.63] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
To evaluate effects of multiple dosing of ketoconazole (KTZ) on hepatic CYP3A, the pharmacokinetics of intravenous midazolam (MDZ, 0.5 mg/kg) before and during multiple dosing of KTZ were investigated in beagle dogs. KTZ tablets were given orally to dogs (n = 4) for 30 days (200 mg b.i.d.). With coadministration of KTZ, t(1/2beta) of MDZ were significantly increased both on day 1 (2-fold) and on day 30 (3-fold). Total body clearance (CL(tot)) of MDZ declined gradually during the first 5 days after the start of KTZ treatment, and thereafter CL(tot) appeared to reach a plateau phase (one-fourth), depending on plasma KTZ concentrations. The effects of KTZ on the biotransformation of MDZ were also investigated using dog liver microsomes (n = 5). The K(i) values of KTZ for MDZ 1'-hydroxylation and 4-hydroxylation were 0.0237 and 0.111 microM, respectively, indicating that KTZ extensively inhibits hepatic CYP3A activity in dogs. CL(tot) values estimated from in vitro K(i) values corrected by unbound fraction of KTZ and unbound concentrations of the drug in plasma were consistent with in vivo CL(tot) of MDZ. The results in this study suggest that KTZ treatment is necessary until plasma concentrations of the drug reach a steady state to evaluate the effect of multiple dosing of the drug on hepatic CYP3A in vivo. In addition, it is suggested that K(i) values corrected by unbound fraction of KTZ and unbound concentrations of the drug in plasma enable precise in vitro-in vivo scaling.
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Affiliation(s)
- Masanori Kuroha
- Department of Veterinary Medicine, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-0054, Japan
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Koks CH, Crommentuyn KM, Hoetelmans RM, Burger DM, Koopmans PP, Mathôt RA, Mulder JW, Meenhorst PL, Beijnen JH. The effect of fluconazole on ritonavir and saquinavir pharmacokinetics in HIV-1-infected individuals. Br J Clin Pharmacol 2001; 51:631-5. [PMID: 11422025 PMCID: PMC2014488 DOI: 10.1046/j.0306-5251.2001.01409.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
AIMS To study the effect of fluconazole on the steady-state pharmacokinetics of the protease inhibitors ritonavir and saquinavir in HIV-1-infected patients. METHODS Five subjects treated with saquinavir and three with ritonavir received the protease inhibitor alone (saquinavir 1200 mg three times daily, ritonavir 600 mg twice daily) on day 1, and the same protease inhibitor in combination with fluconazole (400 mg on day 2 and 200 mg on days 3 to 8). Pharmacokinetic parameters were determined on days 1 and 8. RESULTS In the saquinavir group, the median increase in the area under the plasma concentration vs time curve was 50% from 1800 microg l(-1) h to 2700 microg l(-1) h (P = 0.04, median increase: 900 microg l(-1) h; 2.5 and 97.5 percentile: 500-1300), and 56% for the peak concentration in plasma (from 550 to 870 microg l(-1), P = 0.04; median increase: 320 microg l(-1) h, 2.5 and 97.5 percentile: 60-450 microg l(-1)). In the ritonavir group, there were no detectable changes in the pharmacokinetic parameters on addition of fluconazole. CONCLUSIONS Because of the favourable safety profile of saquinavir, dose adjustments are probably not necessary with concomitant use of fluconazole, as is the case for ritonavir.
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Affiliation(s)
- C H Koks
- Department of Pharmacy and Pharmacology, Slotervaart Hospital, Amsterdam, The Netherlands.
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Wimberley SL, Haug MT, Shermock KM, Qu A, Maurer JR, Mehta AC, Schilz RJ, Gordon SM. Enhanced cyclosporine-itraconazole interaction with cola in lung transplant recipients. Clin Transplant 2001; 15:116-22. [PMID: 11264638 DOI: 10.1034/j.1399-0012.2001.150206.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND Invasive aspergillosis is a major cause of morbidity and mortality in lung transplant recipients (LTR), occurring in up to 15% of patients post-transplant. The 14% aspergillus incidence at the Cleveland Clinic Foundation prompted institution of universal prophylaxis with oral itraconazole (ICZ) in 1997. We report our experience with two protocols of ICZ administration in non-cystic fibrosis LTR and the interaction with cyclosporine (CSA). METHODS Group 1 patients (n=12) were administered ICZ capsules in a fasting or fed state, with or without a histamine-2 (H-2) receptor antagonist or proton pump inhibitor. Group 2 patients (n=12) received the same protocol as group I, but in a fed state with a carbonated beverage (cola) to increase acidity in the stomach to enhance absorption of ICZ. The ICZ dose was 200 mg/d, given as one daily dose. A historical control group (n=10) did not receive chemoprophylaxis with ICZ. CSA daily doses, dose intervals, concentration, cost, and random ICZ levels were documented over a 4-month period of time and compared using generalized estimating equations. RESULTS The daily CSA mg/kg/d dose decreased over time in all three groups, but no differences were found between the three groups. The CSA dosing interval over time was significantly prolonged in group 2 compared to group 1 or the control group (p< or =0.003). Over time, there was no difference in CSA concentration between all groups. There was no difference in cost over time between the three groups; however, the mean cost of CSA therapy was significantly lower in group 2 compared to the control group (p=0.025). Group 2 administered ICZ with cola had greater random blood concentrations of ICZ (p=0.019). CONCLUSIONS ICZ capsules administered in a fed state with a cola resulted in greater random levels of ICZ, a decrease in cost/d of CSA, and a prolongation of CSA dosing interval. Although daily CSA dosage trended lower in group 2, it did not reach statistical significance. We believe these changes in CSA dosing over time reflect increased absorption of ICZ and recommend verifying ICZ absorption with an itraconazole level, especially when CSA intervals are not prolonged.
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Affiliation(s)
- S L Wimberley
- Department of Pharmacy, Loyola University Medical Center, Maywood, IL, USA
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Georgopapadakou NH. Update on antifungals targeted to the cell wall: focus on beta-1,3-glucan synthase inhibitors. Expert Opin Investig Drugs 2001; 10:269-80. [PMID: 11178340 DOI: 10.1517/13543784.10.2.269] [Citation(s) in RCA: 103] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Currently available antifungal drugs for serious infections are either fungistatic and vulnerable to resistance (azoles) or fungicidal but toxic to the host (polyenes). Cell wall-acting antifungals are inherently selective and fungicidal, features that make them particularly attractive for clinical development. Three classes of such compounds, targeted respectively to chitin synthase (nikkomycins), beta-1,3-glucan synthase (echinocandins) and mannoproteins (pradimicins/benanomicins), have entered clinical development. While nikkomycins and pradimicins/benanomicins are no longer in development, echinocandins have emerged as potentially clinically useful and three compounds, caspofungin (MK-991, L-743,872), micafungin (FK-463) and anidulafungin (LY-303366) are in late clinical development (Phase II and III).
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Affiliation(s)
- N H Georgopapadakou
- DuPont Pharmaceuticals, Experimental Station, E400/3456A, P.O. Box 80400, Wilmington, DE 19880-0400, USA.
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Tiberghien F, Kurome T, Takesako K, Didier A, Wenandy T, Loor F. Aureobasidins: structure-activity relationships for the inhibition of the human MDR1 P-glycoprotein ABC-transporter. J Med Chem 2000; 43:2547-56. [PMID: 10891114 DOI: 10.1021/jm990955w] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Cyclic depsipeptide cyclo-[D-Hmp(1)-L-MeVal(2)-L-Phe(3)-L-MePhe(4)-L-Pro(5)-L-aIle+ ++(6)-L-MeVal(7)-L-Leu(8)-L-betaHOMeVal(9)], the antifungal antibiotic aureobasidin A (AbA), was reported to interfere with ATP-binding cassette (ABC) transporters in yeast and mammalian cells, particularly the MDR1 P-glycoprotein (Pgp), a transmembrane phospholipid flippase or "hydrophobic vacuum cleaner" that mediates multidrug resistance (MDR) of cancer cells. In a standardized assay that measures Pgp function by the Pgp-mediated efflux of the calcein-AM Pgp substrate and uses human lymphoblastoid MDR-CEM (VBL(100)) cells as highly resistant Pgp-expressing cells and the cyclic undecapeptide cyclosporin A (CsA) as a reference MDR-reversing agent (IC(50) of 3.4 microM), AbA was found to be a more active Pgp inhibitor (IC(50) of 2.3 microM). Out of seven natural analogues and 18 chemical derivatives of AbA, several were shown to display even more potent Pgp-inhibitory activity. The Pgp-inhibitory activity was increased about 2-fold by some minor modifications such as those found in the naturally occurring aureobasidins AbB ([D-Hiv(1)]-AbA), AbC ([Val(6)]-AbA), and AbD [gammaHOMeVal(9)]-AbA). The replacement of the [Phe(3)-MePhe(4)-Pro(5)] tripeptide by an 8-aminocaprylic acid or the N(7)()-desmethylation of MeVal(7) led to only a 3.3-fold decreased capacity to inhibit Pgp function, suggesting that the Pgp inhibitory potential of aureobasidins, though favored by the establishment of an antiparallel beta-sheet between the [D-Hmp(1)-L-MeVal(2)-L-Phe(3)] and [L-aIle(6)-L-MeVal(7)-L-Leu(8)-] tripeptides, does not critically depend on the occurrence of the [L-Phe(3)-L-MePhe(4)-L-Pro(5)-L-aIle(6)] type II' beta-turn secondary structure. In contrast, the most potent Pgp inhibitors were found among AbA analogues with [betaHO-MeVal(9)] residue alterations, with some data suggesting a negative impact of the [L-Leu(8)-L-betaHOMeVal(9)-D-Hmp(1)] gamma-turn secondary structure on Pgp inhibitory potential. The [2,3-dehydro-MeVal(9)]-AbA was the most potent Pgp inhibitory aureobasidin, being 13-fold more potent than AbA and 19-fold more potent (on a molar basis) than CsA. Finally, there was no correlation between the SAR for the human MDR1 Pgp inhibition and the SAR for Saccharomyces cerevisiae antifungal activity, which is mediated by an inositol phosphoceramide synthase activity.
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Affiliation(s)
- F Tiberghien
- Laboratory of Immunology, Strasbourg 1 University, Illkirch, France
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Venkatakrishnan K, von Moltke LL, Greenblatt DJ. Effects of the antifungal agents on oxidative drug metabolism: clinical relevance. Clin Pharmacokinet 2000; 38:111-80. [PMID: 10709776 DOI: 10.2165/00003088-200038020-00002] [Citation(s) in RCA: 367] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
This article reviews the metabolic pharmacokinetic drug-drug interactions with the systemic antifungal agents: the azoles ketoconazole, miconazole, itraconazole and fluconazole, the allylamine terbinafine and the sulfonamide sulfamethoxazole. The majority of these interactions are metabolic and are caused by inhibition of cytochrome P450 (CYP)-mediated hepatic and/or small intestinal metabolism of coadministered drugs. Human liver microsomal studies in vitro, clinical case reports and controlled pharmacokinetic interaction studies in patients or healthy volunteers are reviewed. A brief overview of the CYP system and the contrasting effects of the antifungal agents on the different human drug-metabolising CYP isoforms is followed by discussion of the role of P-glycoprotein in presystemic extraction and the modulation of its function by the antifungal agents. Methods used for in vitro drug interaction studies and in vitro-in vivo scaling are then discussed, with specific emphasis on the azole antifungals. Ketoconazole and itraconazole are potent inhibitors of the major drug-metabolising CYP isoform in humans, CYP3A4. Coadministration of these drugs with CYP3A substrates such as cyclosporin, tacrolimus, alprazolam, triazolam, midazolam, nifedipine, felodipine, simvastatin, lovastatin, vincristine, terfenadine or astemizole can result in clinically significant drug interactions, some of which can be life-threatening. The interactions of ketoconazole with cyclosporin and tacrolimus have been applied for therapeutic purposes to allow a lower dosage and cost of the immunosuppressant and a reduced risk of fungal infections. The potency of fluconazole as a CYP3A4 inhibitor is much lower. Thus, clinical interactions of CYP3A substrates with this azole derivative are of lesser magnitude, and are generally observed only with fluconazole dosages of > or =200 mg/day. Fluconazole, miconazole and sulfamethoxazole are potent inhibitors of CYP2C9. Coadministration of phenytoin, warfarin, sulfamethoxazole and losartan with fluconazole results in clinically significant drug interactions. Fluconazole is a potent inhibitor of CYP2C19 in vitro, although the clinical significance of this has not been investigated. No clinically significant drug interactions have been predicted or documented between the azoles and drugs that are primarily metabolised by CYP1A2, 2D6 or 2E1. Terbinafine is a potent inhibitor of CYP2D6 and may cause clinically significant interactions with coadministered substrates of this isoform, such as nortriptyline, desipramine, perphenazine, metoprolol, encainide and propafenone. On the basis of the existing in vitro and in vivo data, drug interactions of terbinafine with substrates of other CYP isoforms are unlikely.
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Affiliation(s)
- K Venkatakrishnan
- Department of Pharmacology and Experimental Therapeutics, Tufts University School of Medicine, Boston, Massachusetts 02111, USA
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Auclair B, Berning SE, Huitt GA, Peloquin CA. Potential interaction between itraconazole and clarithromycin. Pharmacotherapy 1999; 19:1439-44. [PMID: 10600094 DOI: 10.1592/phco.19.18.1439.30907] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Three patients negative for human immunodeficiency virus infection were admitted for pulmonary Mycobacterium avium complex (MAC) and aspergillosis infections. They were treated with different drug combinations, but all regimens included clarithromycin for MAC and itraconazole for aspergillosis. All patients experienced an increase in clarithromycin concentrations and clarithromycin: 14-OH-clarithromycin ratio compared with expected range values. They had no clinical side effects. The time course suggested a possible interaction between clarithromycin and itraconazole, presumably through itraconazole's effects on cytochrome P450 3A4 activity. A bidirectional interaction cannot be ruled out. The data suggest that, when necessary, these two drugs can be administered together safely. Further investigation is necessary to determine the extent and clinical consequences of coadministration in humans.
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Affiliation(s)
- B Auclair
- Department of Medicine, National Jewish Center for Immunology and Respiratory Medicine, University of Colorado, Denver 80206, USA
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