Define Fluconazole
It is a weaker inhibitor of CYP3A4 than itraconazole or ketoconazole but may still increase serum concentrations of drugs metabolized by 3A4, like cyclosporine, simvastatin (Zocor) and lovastatin (Mevacor, and others). Fluconazole is a strong inhibitor of CYP2C9 and can therefore enhance serum concentrations of tacrolimus, phenytoin (Dilantin, and others), zidovudine (Retrovir), warfarin (Coumadin, and others) and other drugs metabolized by 2C9. Concomitant administration of rifampin (Rifadin, and others) can lower serum concentrations of fluconazole.