Griseofulvin isnot useful in one of the following:

HETEROCYCLIC BENZOFURAN Griseofulvin It was one of the early antibiotics extracted from Penicillium griseofulvum. However, because of lack of antibacterial activity, little attention was paid to it: clinical utility in dermatophytosis was demonstrated only around 1960. Griseofulvin is active against most dermatophytes, including Epidermophyton, Trichophyton, Microsporum, etc., but not against Candida and other fungi causing deep mycosis. Bacteria are also insensitive. Dermatophytes actively concentrate it: this feature probably accounts for its selective toxicity. Resistance can be induced in vitro and this is associated with loss of concentrating ability. However, emergence of resistance during clinical use is rare. Griseofulvin interferes with mitosis-multinucleated and stunted fungal hyphae result from its action. It also causes abnormal metaphase configurations. However, unlike the typical mitotic inhibitors (colchicine, vinca alkaloids), it does not cause metaphase arrest; rather the daughter nuclei fail to move apa or move only a sho distance. It does not inhibit polymerization of tubulin (microtubular protein which pulls the chromosomes apa), but binds to polymerized microtubules and somehow disorients them. ESSENTIALS OF MEDICAL PHARMACOLOGY K.D.TRIPATHI SIXTH EDITION PAGE NO:760