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BackItraconazole Data - Uses, Dosage, Drug class, Brand name, Warnings, etc
| Pharmacology |
Itraconazole is a synthetic triazole antifungal agent, more active than ketoconazole or fluconazole against certain fungi, notably Aspergillus spp. Also active against Coccidioides, Cryptococcus, Candida, Histoplasma, Blastomyces, and Sporotrichosis spp. Inhibits fungal cytochrome P450-dependent enzymes, blocking ergosterol biosynthesis, disrupting membrane function, and affecting fungal cell growth/viability. |
|---|---|
| Adult Dosage |
PO for systemic fungal infections: - 200–600 mg/day, depending on site/severity; doses >200 mg/day in 2–3 divided doses PO for vulvovaginal candidiasis: - 200 mg twice daily for 1 day - OR 200 mg/day for 7 days PO for dermatomycoses: - 100 mg/day for 15 days - OR 200 mg/day for 7 days PO for pityriasis versicolor: - 200 mg/day for 7 days PO for plantar tinea pedis/palmar tinea manuum: - 100 mg/day for 30 days - OR 200 mg twice daily for 7 days PO for onychomycosis: - 200 mg once daily for 3 months IV for blastomycosis, histoplasmosis, aspergillosis: - 200 mg twice daily for 4 doses, then 200 mg/day |
| Pediatric Dosage | Safety and efficacy not established. |
| Geriatric Dosage | Same as adult dosage. |
| Other Conditions |
Hepatic impairment: - Dosage reduction may be needed; no specific guidelines Renal impairment: - No adjustment needed - IV not recommended if Clcr <30 mL/min |
| Dosage Forms |
- Capsule: 100 mg - Oral Solution: 10 mg/mL - Injection: 10 mg/mL |
| Patient Instructions |
- Take with food to maximize absorption - Avoid medications that reduce stomach acid (e.g., antacids, H2-blockers, omeprazole) - Report fatigue, loss of appetite, nausea, vomiting, yellowing of skin, dark urine, or pale stools |
| 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 |
Serum Levels: - <5 mg/L (<7 µmol/L) associated with treatment failure in Aspergillus infections Fate: - Capsule bioavailability: >70% vs. oral solution - Solubility enhanced by acidic environment, food - Peak concentration: 4–5 hr; fasting 20 µg/L (28 nmol/L) at 100 mg, 180 µg/L (0.26 µmol/L) with food - Protein binding: >99% (primarily albumin); 0.2% free drug - Highly lipid-soluble; tissue concentrations > serum - Hepatic metabolism; dose-dependent elimination - Active metabolite hydroxyitraconazole: Serum levels double itraconazole at steady state Half-life: - 24–42 hr; possibly longer with high doses |
| Adverse Reactions |
General: Well tolerated long-term Frequent: - Mild, transient transaminase elevations Occasional: - Rash, pruritus, nausea, vomiting, abdominal discomfort, headache, dizziness, decreased libido, hypertension Rare: - Hepatotoxicity (fatal cases reported) - Negative inotropic effect; may worsen CHF - No effects on testicular/adrenal steroidogenesis |
| Contraindications | Coadministration with astemizole, cisapride, oral midazolam, pimozide, quinidine, dofetilide, triazolam, or HMG-CoA reductase inhibitors metabolized by CYP3A4. |
| Precautions |
- Pregnancy - Lactation - Avoid for onychomycosis in ventricular dysfunction (e.g., CHF) |
| Drug Interactions |
- Inhibits CYP3A3/4, increasing levels of cyclosporine, warfarin, contraindicated drugs - Warfarin: May require dose reduction - Cyclosporine: Reduce dose by ~50% with itraconazole >100 mg/day - Avoid carbamazepine, phenytoin, rifampin (reduce itraconazole levels) |
| Parameters to Monitor |
- Prothrombin time with warfarin - Cyclosporine levels - Liver function tests in hepatic impairment - Serum itraconazole levels if poor absorption/increased metabolism suspected |
References
Hand of Clinical Drug Data