Ketoconazole
NIZORAL
What it isImidazole antifungal enzyme inhibitor; fungal infections, with systemic use now restricted.
Why this oneIts steroid-synthesis blockade makes oral ketoconazole useful for lowering cortisol in Cushing syndrome.
What limits itSystemic use can cause severe hepatotoxicity and QT prolongation; potent CYP3A4 inhibition drives major interactions.
FDA-approved for
- fungal infections (1981)
- Cushing syndrome (off-label)
FDA label
Read the full label on DailyMed ↗
BOXED WARNING Hepatotoxicity (some fatal); not for onychomycosis or skin/Candida infections—use only when other antifungals unavailable/not tolerated; QT prolongation with certain coadministered drugs
| FDA dosing | Population | Start | Target | Max |
|---|---|---|---|---|
| Systemic fungal infection | adult | 200 mg QD | 400 mg QD | |
| Systemic fungal infection | children >2 yr | 3.3-6.6 mg/kg QD |
Renal Undefined
Hepatic Undefined
Instructions
- Document infection (lab and clinical) before starting
- Usual duration for systemic infection is 6 months; continue until active infection subsides
- Not studied in children under 2 yr
Cautions
- Hepatotoxicity, including fatalities—monitor liver function
- QT prolongation/torsades with coadministered drugs
- Anaphylaxis/anaphylactoid reactions
- Adrenal insufficiency at higher doses (cortisol suppression)
Adverse reactions
- Nausea, vomiting, abdominal pain
- Hepatitis, jaundice, abnormal hepatic function
- Rash, pruritus, urticaria
- Headache, dizziness
- Gynecomastia
Pregnancy Undefined
Lactation Undefined
⚠ BOXED WARNINGS
- Hepatotoxicity
- QT prolongation and drug interactions
Cost, est. cash$5–$150/month
Generic entry1986
Classes and tags
Clinical profile
Legacy pregnancy categoryC
Defining liabilitySevere hepatotoxicity, adrenal suppression and strong CYP3A inhibition restrict systemic use.
Mechanism of action: Ketoconazole ballicule
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