Fluconazole drug interactions

Mootha W, Schluter ML, Das A Intraocular hemorrfiages due to warfarin-fluconazole drug interaction in a patient with presumed Candida endophthalmitis Arch Oj tdiabmA (2002) 120,94-5. 

Levin TT, Cortes-Ladino A, Weiss M, Palomba ML. Life-threatening serotonin toxicity due to a citalopram-fluconazole drug interaction case reports and discussion. Gen Hosp Psychiatry 2008 30 372-7. 

If immunocompromised patients experience frequent or severe recurrences, particularly of esophageal candidiasis, chronic maintenance therapy with fluconazole 100 to 200 mg daily should be considered. In patients with infrequent or mild cases, secondary prophylaxis is not recommended. The rationale for not giving prophylaxis includes availability of effective treatments for acute episodes, risk of developing resistant organisms, potential for drug interactions, and the cost of therapy. 

Itraconazole and ketoconazole (200-800 mg/day orally for 1 year) are effective in 74% to 86% of cases, but relapses are common fluconazole 200-400 mg daily is less effective (64%) than ketoconazole or itraconazole, and relapses are seen in 29% of responders Severe disease Amphotericin B 0.7 mg/kg/day for a minimum total dose of 35 mj kg is effective in 59% to 100% of cases and should be used in patients who require hospitalization or are unable to take itraconazole because of drug interactions, allergies, failure to absorb drug or failure to improve clinically after a minimum of 12 weeks of itiaconazole therapy... 

Black DJ, Kunze KL, Wienkers LC, et al. Warfarin-fluconazole. II.A metabolically based drug interaction in vivo studies. Drug Metab Dispos 1996 24(4) 422-428. 

Because trimetrexate is metabolized by a P450 enzyme system, drugs that induce or inhibit this drug metabolizing enzyme system may elicit important drug interactions that may alter trimetrexate plasma concentrations, which include erythromycin, rifampin, rifabutin, ketoconazole, fluconazole, cimetidine, nitrogen substituted imidazole drugs (eg, clotrimazole, ketoconazole, miconazole). 

The importance of these enzymes for drug interactions is that enzyme inducers and inhibitors may preferentially affect certain isoforms and consequently may only affect the metabolism of selected drugs. For example, ketoconazole has the potential to inhibit the metabolism of drugs metabolised to a great extent by the sub-family 3A (e.g. midazolam) but not of those metabolised by sub-family 1A (e.g. theophylline), 2C (e.g. diazepam), or 2D (e.g. metaprolol). In contrast, although fluconazole is a weaker inhibitor of the sub-family 3A than ketoconazole, it also inhibits the sub-family 2C, and so the interactions of fluconazole differ from those of ketoconazole. 

The adverse effects that most frequently result in discontinuation of rifabutin include GI intolerance, rash, and neutropenia. Rifabutin levels will be increased with concurrent administration of fluconazole and clarithromycin, resulting in anterior uveitis, polymyalgia syndrome, and a yellowish-tan discoloration of the skin (pseudojaundice). Other adverse reactions are similar to those of rifampin, such as hepatitis, red-orange discoloration of body fluids, and drug interactions due to effects on the hepatic P450 cytochrome enzyme system. 

Since indinavir is a substrate as well as an inhibitor of CYP3 A4, numerous and complex drug interactions can occur as described above. Indinavir levels decrease with concurrent use of rifabutin, fluconazole, St. John s wort, and rifampin. Caution is advised with other 3 A4 inducers also, including phenobarbital, phenytoin, carbamezepine, and dexamethasone. Dose reduction of indinavir should be considered if coadministered with delavirdine, ketoconazole, or itraconazole, while an increase in the dose of indinavir is indicated if the drug is coadministered with efavirenz or rifabutin. 

Kunze KL, Trager WF. Warfarin-fluconazole. 3. A rational approach to management of a metabolically based drug-interaction. Drug Metab Dispos 1996 24 429-435. 

ITRACONAZOLE, FLUCONAZOLE, MICONAZOLE, VORICONAZOLE SULPHONYLUREAS t risk of hypoglycaemic episodes Inhibition of CYP2C9-mediated metabolism of these sulphonylureas Watch for and warn patients about symptoms of hypoglycaemia >- For signs and symptoms of hypoglycaemia, see Clinical Features of Some Adverse Drug Interactions, Hypoglycaemia... 

Fluconazole is contraindicated in patients who have shown hypersensitivity to fluconazole or to any of its components. There is no information regarding crosshypersensitivity between fluconazole and other azole antifungal agents. Caution should be used in prescribing fluconazole to patients with hypersensitivity to other azoles. Refer to Table 11-14 for drug interactions. 

Gupta AK, Katz HI, Shear NH. Drug interactions with itraconazole, fluconazole, and terbinafine and their management. J Am Acad Dermatol 1999 41(2 Pt l) 237-49. 

Lazar JD, Wilner KD. Drug interactions with fluconazole. Rev Infect Dis 1990 12(Suppl 3) S327-33. 

Osowski CL, Dix SP, Lin LS, Mullins RE, Geller RB, Wingard JR. Evaluation of the drug interaction between intravenous high-dose fluconazole and cyclosporine or... 

Tarumi Y, Pereira J, Watanabe S. Methadone and fluconazole respiratory depression by drug interaction. J Pain Symptom Manage 2002 23(2) 148-53. 

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