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BackFluconazole Data - Uses, Dosage, Drug class, Brand name, Warnings, etc
| Pharmacology | Fluconazole, a highly water-soluble triazole antifungal, inhibits fungal cytochrome P450-dependent enzymes, preventing lanosterol conversion to ergosterol, disrupting fungal cell membranes. It is active against Candida spp., Cryptococcus spp., Blastomyces dermatitidis, Coccidioides immitis, and Histoplasma capsulatum. |
|---|---|
| Administration and Adult Dosage |
- PO or IV for oropharyngeal/esophageal candidiasis: 200 mg on day 1, then 100 mg/day for 10–14 days; up to 400 mg/day for severe esophageal candidiasis - PO or IV for cryptococcal meningitis: • Short-term: 400 mg/day for 6–10 weeks • Maintenance (AIDS patients): 200 mg/day indefinitely; up to 1 g/day used - PO for uncomplicated vaginal candidiasis: 150 mg single dose - PO or IV for coccidioidal meningitis: 400 mg/day indefinitely; up to 800 mg/day used - PO or IV for candidiasis prophylaxis (bone marrow transplant): 400 mg/day, start days before neutropenia, continue 7 days after granulocyte count >1000/µL |
| Special Populations - Pediatric Dosage |
- PO or IV for candidiasis: 6 mg/kg loading dose, then 3 mg/kg/day for ≥2 weeks (oropharyngeal) or ≥3 weeks/2 weeks post-symptom resolution (esophageal); up to 12 mg/kg/day used - PO or IV for systemic candidiasis: 6–12 mg/kg/day - PO or IV for cryptococcal meningitis (treatment/prophylaxis): 12 mg/kg loading dose, then 6 mg/kg/day; treat ≥10–12 weeks post-negative CSF cultures; prophylaxis in HIV-infected children continues indefinitely |
| Special Populations - Geriatric Dosage | Same as adult dosage; adjustment usually unnecessary despite prolonged half-life (>65 yr), unless severe renal impairment (see Other Conditions). |
| Other Conditions |
- Renal impairment: • Clcr 20–50 mL/min: Usual dose every 48 hr • Clcr 10–19 mL/min: 50–200 mg every 48 hr • Clcr <10 mL/min: 50–100 mg every 48 hr • Hemodialysis: Full dose post-dialysis • Chronic ambulatory peritoneal dialysis: 50–200 mg/day |
| Dosage Forms |
- Tablet: 50, 100, 150, 200 mg - Suspension: 10, 40 mg/mL - Injection: 2 mg/mL |
| Patient Instructions |
- Take with a meal if stomach upset occurs - Report changes in appetite, dark urine, or light stools to your physician |
| Missed Doses | - Take missed dose as soon as remembered; if near next dose, take only that dose, leaving ≥12 hr between doses; do not double dose |
| Pharmacokinetics - Fate |
- Absorption: 90% oral bioavailability, unaffected by gastric pH - Peak Levels: 1.8–2.8 mg/L (5.9–9 µmol/L) 2–4 hr post 100–150 mg oral dose - Protein Binding: 11–12% - Distribution: Vd = 0.65 ± 0.2 L/kg; CSF penetration >60% of serum levels - Clearance: Cl = 0.015 ± 0.006 L/hr/kg - Excretion: 64–90% unchanged in urine |
| Pharmacokinetics - t¹⁄₂ | - 22 ± 4 hr (normal); 37 hr (>65 yr); up to 125 hr (renal impairment) |
| Adverse Reactions & Side Effects |
Occasional: - Nausea, vomiting, diarrhea, abdominal pain, elevated liver transaminases Rare: - Severe hepatitis, exfoliative skin reactions |
| Contraindications | - Hypersensitivity to fluconazole or triazoles |
| Precautions & Warnings |
- Monitor for worsening rash; discontinue if lesions progress - Use cautiously in patients with hepatic impairment - Risk of hepatotoxicity; monitor closely if transaminases elevated |
| Drug Interactions |
- Rifampin induces fluconazole metabolism, risking clinical failure - Inhibits metabolism of phenytoin, warfarin, cyclosporine (minor) - Increases levels of tolbutamide, glipizide, glyburide, possibly other sulfonylureas, enhancing hypoglycemic effects; may require dose adjustment |
| Parameters to Monitor |
- Liver function tests (ALT, AST) weekly initially, then monthly - Renal function weekly if abnormal at baseline - Monitor for signs of hepatitis in patients with elevated transaminases - Assess clinical/microbiologic response to infection |
| Class and Drug Brand Name |
- Class: Triazole Antifungals - Brand Name: Diflucan |
| Notes |
- Combination with flucytosine for cryptococcal meningitis may be superior to monotherapy; further studies with amphotericin B needed - Fluconazole-resistant Candida albicans reported; prophylactic use increases risk of resistant strains (e.g., Candida krusei) - Effective for a range of fungal infections, particularly cryptococcal and candidal infections |
References
Hand of Clinical Drug Data