GRISEOFULVIN

antibiotic produced by the molds Penicillium griseofulvum and P. janczewski. Although used to treat ringworm, athlete's foot, and diseases of the hair and nails, it is ineffective against conditions caused by other fungi, yeasts, or bacteria. Griseofulvin exerts its antimicrobial activity by altering the nucleic acid metabolism in those microorganisms against which it is effective.