Griseofulvin
GRIFULVIN
Pronunciation: gri-see-oe-FUL-vin
“Greasy fulcrum”
What it isAntifungal disrupting fungal microtubules; dermatophyte infections of hair and skin.
Why this oneMicrosporum tinea capitis is the niche where it can outperform terbinafine.
What limits itLong courses and hepatic enzyme induction complicate use; hormonal contraception and warfarin can lose effect.
Griseofulvin prescription history
Animated chart of estimated U.S. prescriptions per year, Antifungals (1947–2026). Griseofulvin enters in 1959 (estimated).
FDA-approved for
- dermatophyte infections (~1959)
Principal riskIt induces CYP3A4, so contraception fails
Classes and tags
Clinical profile
Legacy pregnancy categoryUnknown / historical label unavailable
Defining liabilityHepatotoxicity and clinically important CYP/QT interactions; organ toxicity varies markedly by agent.
FDA label
Read the full label on DailyMed ↗
NO BOXED WARNINGS
| FDA dosing | Population | Start | Target | Max |
|---|---|---|---|---|
| Dermatophyte infections of skin, hair, nails (tinea corporis, pedis, cruris, barbae, capitis, unguium) | Adults | 0.5 g/day (125 mg QID, 250 mg BID, or 500 mg QD); widespread lesions 0.75–1 g/day | Reduce gradually to 0.5 g/day or less after response | Undefined |
| Dermatophyte infections of skin, hair, nails | Pediatric >2 years | 10 mg/kg/day (30–50 lb: 125–250 mg/day; >50 lb: 250–500 mg/day, divided) | Individualized | Undefined (safety >10 mg/kg/day not established) |
Renal Undefined
Hepatic Contraindicated in hepatocellular failure
Safety is not established at higher doses than recommended. Not established in pediatric patients 2 years and younger.
Instructions
- Continue until organism eradicated: tinea capitis 4–6 wk, corporis 2–4 wk, pedis 4–8 wk, fingernails ≥4 mo, toenails ≥6 mo
- Appropriate topical agents usually also required, particularly in tinea pedis
Available strengths
- tab 125, 165, 250, 500 mg
- susp 125 mg/5 mL
Contraindications
- Porphyria
- Hepatocellular failure
- Women who are or may become pregnant (conjoined twins reported with first-trimester use)
Cautions
- Prophylactic use not established
- Serious skin reactions (SJS, TEN, erythema multiforme) — discontinue
- Hepatotoxicity (AST/ALT/bilirubin elevations, jaundice) — monitor
- Prolonged therapy: periodic renal, hepatic, hematopoietic monitoring
- Possible cross-sensitivity with penicillin
- Lupus erythematosus / lupus-like syndromes
- Photosensitivity — avoid intense or prolonged sunlight
- Interactions: warfarin, oral contraceptives (reduced efficacy), cyclosporine, salicylates, barbiturates, alcohol
Adverse reactions
- Skin rashes, urticaria (hypersensitivity type)
- Rarely angioneurotic edema, erythema multiforme
- Peripheral neuropathy, paresthesias of hands/feet
- Oral thrush
- Nausea, vomiting, epigastric distress, diarrhea
- Headache, fatigue, dizziness, insomnia, mental confusion
Pregnancy Contraindicated (Category X) — conjoined twins reported with first-trimester use; embryotoxic/teratogenic in animals
Lactation Unknown if excreted in human milk; decide whether to discontinue nursing or the drug (animal tumorigenicity)
Cost
Generic entry1982
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Memory aids: interaction avatars
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Self-check
- Which tinea capitis organism is a griseofulvin niche over terbinafine?
Microsporum. - How can griseofulvin affect hormonal contraception?
Reduce its effect through enzyme induction.