KETOCONAZOLE AND FLUCONAZOLE DRUG-INTERACTIONS

This article reviews potential drug interactions that exist between ke toconazole or fluconazole and other drugs. English-language data sourc es included human subjects' computerized databases and published index es. Case reports and studies demonstrate decreased dosage requirements of cyclosporine sodium, methylprednisolone sodium succinate, and poss ibly anticoagulants and phenytoin after ketoconazole or fluconazole ad ministration, suggesting hepatic enzyme inhibition. Increased dosage r equirements of ketoconazole are necessary after rifampin administratio n, suggesting rifampin's induction of hepatic microsomal enzymes. Poss ibly a similar effect may occur with concomitant fluconazole and rifam pin. The effect of ketoconazole administration on prednisolone sodium phosphate and theophylline warrants further study. Fluconazole, a more selective agent for fungal P-450, seems to be of less concern regardi ng the potential for drug interactions than ketoconazole.