Griseofulvin (Fulvicin P/G, Fulvicin U/F, Gris-Peg, Grisactin)


  • Antifungal


  • Systemic antifungal


  • Fungal infections of the skin, hair, and nails caused by susceptible organisms.

  • Antifungal spectrum usually includes: Trichophyton rubrum, T. tonsurans, T. mentagropytes, T. interdigitalis, T. verrucosum, T. megninii, T. gallinae, T. crateriform, T. sulphureum, T. schoenleinii, Microsporum audouinii, M. canis, M. gypseum, Epidermophyton floccosum


  • Porphyria

  • Hepatocellular failure


  • Pregnancy category C; avoid use during pregnancy; use caution in nursing mothers

  • Penicillin allergy (possible cross-sensitivity)

  • Lupus erythematosus

Adverse Reactions (Side Effects):

  • CNS: dizziness, fatigue, headache, insomnia, mental confusion, paresthesias

  • GI: diarrhea, epigastric distress, BI bleeding, hepatic toxicity, nausea, oral thrush, vomiting

  • GU: menstrual irregularities, proteinuria

  • HEME: granulocytopenia, leukopenia

  • SKIN: angioneurotic edema, photosensitivity, rash, urticaria  


Administered orally (microsize tablets, ultramicrosize tablets, suspension)

  • Adult: (microsize) PO 500-1000mg daily in single or divided doses; (ultramicrosize) 330-375mg daily in single or divided doses, max 750mg daily

  • Child: > or = 2 years: PO (microsize) 10-15 mg/kg/day in single or divided doses; (ultramicrosize) 5.5-7.3 mg/kg/day in single or divided dose

Duration of Treatment:

Condition Duration
Tinea corporis 2-4 weeks
Tinea capitis at least 4-6 weeks
Tinea pedis 4-8 weeks
Tinea unguium 3-6 months

Drug interactions:

  • Reduces the response of : Aspirin, Cyclosporine, Oral Contraceptives, Tacrolimus, and Warfarin

  • Phenobarbital: reduces plasma griseofulvin level

Special considerations:

  • Prior to therapy, the type of fungus responsible for infection should be identified

  • Response to therapy may not be apparent for some time; complete entire course of therapy

  • Avoid prolonged exposure to sunlight

  • Clinician should be notified if sore throat or skin rash occurs

  • Store suspension at room temperature in light-resistant container


Back to Medical Corps Pharmacy Page