Adults

Dosage varies by indication. For vaginal candidiasis: 150 mg single oral dose. For oropharyngeal candidiasis: 50-100 mg once daily for 7-14 days. For esophageal candidiasis: 50-400 mg once daily for 14-30 days. For systemic candidiasis and cryptococcal meningitis: Loading dose of 400 mg on day 1, followed by 200-400 mg once daily.

Elderly

No dose adjustment is typically required in elderly patients with normal renal function. For patients with renal impairment, dose adjustment is necessary.

Renal_impairment

For creatinine clearance (CrCl) >50 mL/min, use usual dose. For CrCl 21-50 mL/min, administer 50% of the usual daily dose. For CrCl <20 mL/min, administer 25% of the usual daily dose. Hemodialysis patients should receive 100% of the recommended dose after each dialysis session.

Onset

Onset of action varies depending on the type and severity of infection, generally within hours to days.

Excretion

Primarily renal; about 80% of the administered dose is excreted unchanged in the urine, and about 11% is excreted as metabolites.

Half life

Approximately 30 hours, which allows for once-daily dosing.

Absorption

Well absorbed orally, with bioavailability of >90% compared to intravenous administration. Peak plasma concentrations are achieved within 1-2 hours.

Metabolism

Minimally metabolized; approximately 11% of the dose is metabolized. It is a potent inhibitor of CYP2C9 and a moderate inhibitor of CYP2C19 and CYP3A4.

Warfarin

Increased prothrombin time; monitor INR closely.

Phenytoin

Increased phenytoin levels; monitor levels and adjust dose.

Rifampicin

Decreased fluconazole levels; consider increasing fluconazole dose.

Hydrochlorothiazide

Increased plasma concentrations of fluconazole.

Oral Hypoglycemics (sulfonylureas)

Increased blood glucose lowering effect; monitor blood sugar.

Cyclosporine, Tacrolimus, Sirolimus

Increased levels of immunosuppressants; monitor levels.

Statins (e.g., Atorvastatin, Simvastatin)

Increased risk of myopathy/rhabdomyolysis.