API

Fluconazole

Drug classification

Dosage form

Capsule

API strength per dosage

50mg

Dose

Adults: 150 mg orally as a single dose for vaginal candidiasis; 200–400 mg once daily for systemic infections. Pediatrics: 6–12 mg/kg once daily (max 400 mg/day). Renal impairment: Reduce dose by 50% if creatinine clearance <50 mL/min (excluding single-dose therapy).

Mechanism of action

Inhibits fungal cytochrome P450 enzyme lanosterol 14α-demethylase (CYP51), blocking conversion of lanosterol to ergosterol, disrupting ergosterol synthesis, increasing fungal cell membrane permeability, and leading to cell death. Selectively targets fungal CYP51 with minimal effect on mammalian cytochrome P450 enzymes.

Indications

Oropharyngeal candidiasis, esophageal candidiasis, vaginal candidiasis, systemic candidiasis, cryptococcal meningitis, candidemia, urinary tract candidiasis, peritonitis due to Candida, prophylaxis of fungal infections in immunocompromised patients.

Side effects

Hepatotoxicity, QT prolongation, rash, Stevens-Johnson syndrome, nausea, vomiting, abdominal pain, diarrhea, headache, dizziness, anaphylaxis, blood dyscrasias (including agranulocytosis, leukopenia, thrombocytopenia).

Pregnancy category

Category D

Precautions

Hepatic impairment, renal impairment, QT prolongation, concurrent use with drugs affecting CYP3A4, hypersensitivity reactions, pregnancy (especially high doses), breastfeeding, electrolyte disturbances, history of arrhythmias, potential for drug interactions, monitor for signs of hepatotoxicity, monitor for skin reactions, adjust dose in renal dysfunction.

Contraindications

Hypersensitivity to fluconazole or azole antifungals, concomitant use with terfenadine (at high doses), concomitant use with cisapride, erythromycin, pimozide, or quinidine, acute porphyria.