Article written and medically reviewed by Dr. Sarah M. Patel, MD, FIDSA – Board-Certified Infectious Diseases Specialist, Fellow of the Infectious Diseases Society of America. Last updated: November 17, 2025
What is Nizoral (Ketoconazole) Used For?
FDA-approved indications (oral tablets):
- Blastomycosis
- Coccidioidomycosis
- Histoplasmosis
- Chromomycosis
- Paracoccidioidomycosis
- Serious chronic mucocutaneous candidiasis
Topical (2% cream/shampoo):
- Tinea corporis, tinea cruris, tinea pedis
- Tinea versicolor (pityriasis versicolor)
- Cutaneous candidiasis
- Seborrheic dermatitis
Off-label (2025 evidence-based):
- Cushing’s syndrome (adrenal blockade)
- Androgenetic alopecia (topical)
- Refractory dermatophytosis
Dosage and Treatment Regimens (2025 IDSA/ESCMID Guidelines)
Oral Ketoconazole – Systemic Mycoses
| Infection | Dose | Duration |
|---|---|---|
| Blastomycosis (non-CNS) | 400–800 mg/day | 6–12 months |
| Coccidioidomycosis | 400 mg/day | 12–18 months |
| Histoplasmosis (mild-moderate) | 400–800 mg/day | 6–12 months |
| Cushing’s syndrome | 600–1,200 mg/day (divided) | Titrate to cortisol control |
Topical 2% Cream & Shampoo
| Condition | Application | Frequency | Duration |
|---|---|---|---|
| Tinea corporis/cruris/pedis | Cream | Once daily | 4 weeks |
| Tinea versicolor | Cream or shampoo | Once daily | 5–7 days |
| Seborrheic dermatitis | Shampoo | Twice weekly | 4–8 weeks |
Comparative Table: Systemic Azole Antifungals (2025)
| Drug | Spectrum | Hepatotoxicity Risk | CYP3A4 Inhibition | QT Prolongation | Current Use |
|---|---|---|---|---|---|
| Ketoconazole | Broad (including dimorphic) | High (1:10,000) | Very strong | Moderate | Reserve / Cushing’s |
| Fluconazole | Candida, Cryptococcus | Low | Weak | Low | First-line |
| Itraconazole | Dimorphic, Aspergillus | Moderate | Strong | Moderate | First-line for many |
| Voriconazole | Aspergillus, Candida | Moderate | Strong | High | First-line invasive |
| Posaconazole | Mucorales, Aspergillus | Low | Strong | Low | Prophylaxis |
Mechanism of Action
Ketoconazole inhibits lanosterol 14α-demethylase (CYP51), blocking ergosterol synthesis and causing fungal cell membrane disruption. It also inhibits human steroidogenesis at high doses (useful in Cushing’s).
Hepatotoxicity & Monitoring (2025 FDA Black Box)
Oral ketoconazole carries a black-box warning for severe hepatotoxicity (including fatalities). LFTs required baseline and weekly × 6 weeks, then monthly.
Official Sources
- FDA Label – Nizoral Tablets (2024): FDA Nizoral Prescribing Information
- EMA – Ketoconazole oral suspension withdrawn (safety): EMA Ketoconazole Assessment
- PubMed – Ketoconazole for Cushing’s (2023 meta-analysis): PubMed 36884335
Real Patient Reviews (2024–2025)
“2% shampoo cleared my seborrheic dermatitis in 2 weeks. No more flakes!”
“Cushing’s – 800 mg/day dropped my cortisol perfectly. LFTs normal.”
“Tinea versicolor gone in 5 days with cream. Best ever.”
“Histoplasmosis resolved with 400 mg/day for 6 months. Mild nausea.”
“Shampoo twice weekly keeps my scalp clear forever.”
Frequently Asked Questions (FAQ)
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