Griseofulvin

Griseofulvin is an antifungal medication used to treat a number of types of dermatophytoses (ringworm). This includes fungal infections of the nails and scalp, as well as the skin when antifungal creams have not worked. It is taken by mouth. Common side effects include allergic reactions, nausea, diarrhea, headache, trouble sleeping, and feeling tired. It is not recommended in people with liver failure or porphyria. Use during or in the months before pregnancy may result in harm to the baby. Griseofulvin works by interfering with fungal mitosis. Griseofulvin was discovered in 1939 from the soil fungus Penicillium griseofulvum. It is on the World Health Organization's List of Essential Medicines. Griseofulvin is used orally only for dermatophytosis. It is ineffective topically. It is reserved for cases in which topical treatment with creams is ineffective. Terbinafine given for 2 to 4 weeks is at least as effective as griseofulvin given for 6 to 8 weeks for treatment of Trichophyton scalp infections. However, griseofulvin is more effective than terbinafine for treatment of Microsporum scalp infections. The drug binds to tubulin, interfering with microtubule function, thus inhibiting mitosis. It binds to keratin in keratin precursor cells and makes them resistant to fungal infections. The drug reaches its site of action only when hair or skin is replaced by the keratin-griseofulvin complex. Griseofulvin then enters the dermatophyte through energy-dependent transport processes and binds to fungal microtubules. This alters the processing for mitosis and also underlying information for deposition of fungal cell walls. It is produced industrially by fermenting the fungus Penicillium griseofulvum. The first step in the biosynthesis of griseofulvin by P. griseofulvin is the synthesis of the 14-carbon poly-β-keto chain by a type I iterative polyketide synthase (PKS) via iterative addition of 6 malonyl-CoA to an acyl-CoA starter unit.