Derived from a species of
Penicillium. Believed to interfere with cell division (metaphase) or DNA replication. When taken systemically, the drug is deposited in the newly formed skin and nails, which are then resistant to reinfection by the tinea. Absorbed from the duodenum.
Peak plasma concentration: 0.5-2 mcg/mL after 4 hr.
1/2: 9-24 hr. Levels may be increased by giving the drug with a high-fat diet. GI absorption of the ultramicrosize products is about 1.5 times that of the microsize products; is no evidence this causes any difference in the safety and effectiveness of the drug compared with the microsize form.
Tinea (ringworm) infections of skin (including athlete's foot), scalp, groin, and nails. Effective against tinea corporis, tinea pedis, tinea barbae, tinea unguium, tinea cruris, tinea capitis due to
Microsporum audouinii, M. canis, M. gypseum and
Epidermophyton floccosum. It is the only PO drug effective against dermatophytid (tinea ringworm) infections. Not effective against
Candida. Establish susceptibility of the infectious agent before treatment is begun.
Pregnancy. Porphyria or history thereof, hepatocellular failure, and hypersensitivity to drug. Exposure to artificial light or sunlight. Use for infections due to bacteria, candidiasis, actinomycosis, sporotrichosis, tinea versicolor, histoplasmosis, chromoblastomycosis, coccidioidomycosis, cryptococcosis, and North American blastomycosis.
Cross sensitivity with penicillin is possible.
Hypersensitivity: Rashes, urticaria,
angioneurotic edema allergic reactions.
GI: N&V, diarrhea, epigastric pain,
CNS: Dizziness, headache, confusion, mental fatigue, insomnia.
Miscellaneous: Oral thrush, acute intermittent porphyria, paresthesias of extremities after long-term therapy, proteinuria, leukopenia, photosensitivity, worsening of lupus erythematosus, menstrual irregularities, hepatic toxicity, granulocytopenia.
Laboratory Test Alterations:
ALT, AST, alkaline phosphatase, BUN, and creatinine level values.
Alcohol, ethyl / Tachycardia and flushing
Anticoagulants, oral /
Anticoagulant effect R/T
Effect of griseofulvin R/T
GI tract absorption
Plasma cyclosporine levels
Oral contraceptives /
Oral contraceptive effect
breakthrough bleeding, pregnancy, or amenorrhea
Serum salicylate levels
Capsule: 250 mg;
Suspension: 125 mg/5 mL;
Tablet: 250 mg, 500 mg.
Tablet: 125 mg; 165 mg; 250 mg; 330 mg
?Capsules, Oral Suspension, Tablets
Tinea corporis, cruris, or capitis.
Adults: 0.5 g griseofulvin microsize daily in a single dose or divided dose (or 330-375 mg ultramicrosize).
Tinea pedis or unguium.
Adults: 0.75-1 g/day of griseofulvin microsize (or 660-750 mg ultramicrosize). After response, decrease dose of microsize to 0.5 g/day.
Pediatric, 13.6-22.7 kg: 125-250 mg griseofulvin microsize daily (or 82.5-165 mg ultramicrosize);
pediatric, over 22.7 kg: 250-500 mg microsize daily (or 165-330 mg ultramicrosize).
NOTE: Dose has not been determined in children less than 2 years of age.