Itracanazol dosage
Itraconazole is an oral antifungal (triazole class) used for a wide range of fungal infections. Dosing varies by indication, formulation, and patient factors.
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itraconazole dosage indications 2025
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https://www.drugs.com/dosage/itraconazole.html
Here is a comprehensive breakdown of Itraconazole dosing by indication:
Itraconazole - Dosage Reference
Formulations
- Capsules: 100 mg (absorption enhanced by food and low gastric pH - take with a full meal)
- Oral solution (cyclodextrin-based, 10 mg/mL): absorption NOT affected by gastric acidity - take on an empty stomach
- IV formulation: avoid if creatinine clearance < 30 mL/min
- Overall dose range: 100-400 mg/day
Adult Dosing by Indication
| Indication | Dose | Duration |
|---|---|---|
| Blastomycosis / Histoplasmosis (non-severe) | 200-400 mg/day orally | 6-12 months |
| Histoplasmosis (life-threatening loading) | 200 mg TID x 3 days, then 200 mg BID | Continued |
| Aspergillosis | 200-400 mg/day (capsules) | Per response |
| Onychomycosis - toenail | 200 mg once daily | 12 consecutive weeks |
| Onychomycosis - fingernail (pulse) | 200 mg BID x 1 week/month | 2 pulses (months) |
| Onychomycosis - fingernail (continuous) | 200 mg/day | 6 weeks |
| Oropharyngeal candidiasis | 200 mg/day oral solution | 1-2 weeks |
| Esophageal candidiasis | 100 mg/day oral solution | ≥ 3 weeks + 2 weeks after symptom resolution |
| Sporotrichosis (lymphocutaneous) | 200 mg/day | Weeks after lesions resolve (typically 3-6 months) |
| Coccidioidomycosis | 200 mg BID | Long-term |
| Tinea corporis/cruris/pedis/PV | 100 mg BID x 5 days | 5 days |
| Paracoccidioidomycosis | 200 mg once daily | 9-18 months |
| Microsporidiosis (HIV) | 400 mg/day | Per response |
| Cryptococcosis (maintenance) | 200 mg/day | Lifelong or per immune status |
Dermatophyte Infections (Dermatology-Specific)
From Fitzpatrick's Dermatology:
- Tinea infections / Pityriasis versicolor: 100 mg BID x 5 days
- Onychomycosis - continuous: 200 mg/day x 6 weeks (fingernails) or 12 weeks (toenails)
- Onychomycosis - pulse: 400 mg/day x 1 week per month
Pediatric Dosing
- General dosing: 5 mg/kg/day (weight-based)
- Twice-daily scheduling is recommended in children (lower plasma concentrations vs. adults)
- Both continuous and pulse regimens can be followed for onychomycosis
- Oral solution is preferred due to better bioavailability
Special Populations
| Situation | Guidance |
|---|---|
| Renal impairment | Caution; no specific dose adjustment defined (avoid IV if CrCl < 30) |
| Hepatic impairment | Dose adjustment required in progressive liver disease (extensive CYP3A4 metabolism) |
| Elderly | Monitor for edema, hypertension, hypokalemia triad |
| Pregnancy | Contraindicated in 1st trimester; use amphotericin B instead |
Key Pharmacology Notes
- Mechanism: Inhibits 14α-demethylase (CYP51), blocking lanosterol → ergosterol conversion
- Half-life: ~21 hours
- Nail reservoir: Drug accumulates in nails for 6-9 months after stopping
- Strong CYP3A4 inhibitor - major drug interactions (e.g., with cisapride, pimozide, quinidine, methadone - contraindicated)
- Rifamycins (rifampin, rifabutin) significantly reduce itraconazole bioavailability
- Does NOT penetrate CSF well - not suitable for fungal meningitis
Boxed Warnings
- Congestive heart failure - negative inotropic effect; avoid in ventricular dysfunction or history of CHF (especially for onychomycosis)
- Cardiac dysrhythmias - life-threatening events with concomitant CYP3A4-metabolized drugs
- Drug interactions - strong CYP3A4 inhibitor
Sources: Katzung's Basic & Clinical Pharmacology (16th ed.), Fitzpatrick's Dermatology, Goldman-Cecil Medicine, Harrison's Principles of Internal Medicine (2025), Drugs.com (updated Jul 2025)
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