Mechanism of griseic acid formation

Under the action of monocarboxylic acids with 1–5 carbon atoms, griseofulvin loses its methyl group from the 2’-methoxy group to become griseofulvic acid

【Category】 Antibiotic drugs. 　　【CAS】126-07-8 　　【Properties】 This product is a white or off-white fine powder ； Odorless, with a slightly bitter taste. 　　【Pharmacology and Toxicology】 This product exhibits strong antibacterial activity against superficial fungi such as Trichophyton, Microsporum, and Epidermophyton. It has no antibacterial effect on genera such as Candida, Cryptococcus, Histoplasma, Sporothrix, Blastomyces, and Coccidioides. This drug inhibits fungal growth by interfering with the synthesis of fungal nucleic acids. 　　【Indications】 This product is suitable for the treatment of various types of tinea, including tinea capitis, tinea barbae, tinea corporis, tinea cruris, tinea pedis, and onychomycosis. The aforementioned tinea diseases are caused by Trichophyton rubrum, Trichophyton tonsurans, Trichophyton mentagrophytes, Trichophyton interdigitale, as well as Microsporum audouinii, Microsporum canis, Microsporum gypseum, and Epidermophyton floccosum. This product is not suitable for mild, localized superficial fungal infections, or those in which topical antifungal agents are already effective. 　　Griseofulvin is ineffective against infections caused by Candida, Histoplasma, Actinomyces, Sporothrix, Blastomyces, Coccidioides, Nocardia, and Cryptococcus, as well as against tinea versicolor. 　　【Formulation】 Griseofulvin tablets 【Dosage and Administration】 The following are the dosages for the particulate form: Adults: For onychomycosis and tinea pedis, 500 mg once, every 12 hours ； For tinea capitis, tinea corporis, or tinea cruris: 250 mg once, every 12 hours, or 500 mg once daily. 　　Children: For those over 2 years of age with a weight of 14–23 kg, the dose is 62.5–125 mg once every 12 hours, or 125–250 mg once daily. For children whose body weight is greater than 23 kg, the dose is 125–250 mg once every 12 hours, or 250–500 mg once daily. 　　【Side Effects】 1 Gastrointestinal reactions include nausea, vomiting, diarrhea, headache, drowsiness, and loss of appetite. 　　2 Allergic reactions present as rashes and erythema, which resolve after discontinuing the drug; occasionally, angioedema or persistent urticaria occurs. 　　3 It may sometimes cause temporary leukopenia, granulocytopenia, transient proteinuria, elevated jaundice indices, and liver function impairment. 　　4 Neuropsychiatric symptoms may also occur, such as depression, insomnia, and delirium. 　　【Contraindications】 1. Alcohol consumption should be avoided during medication use, as it may lead to emotional abnormalities and neurological symptoms. 　　2 It is contraindicated in patients with porphyria, liver failure, pregnant women, and those allergic to this product. Contraindicated in patients with hepatic insufficiency. 　　3 It is not advisable to use it concurrently with phenobarbital, phenytoin sodium, monoamine drugs, and oral anticoagulants such as benzopiron during treatment. 　　【Drug Interactions】 1 Taking this product together with ethanol may cause tachycardia, sweating, and skin flushing; therefore, the two should not be used together. 　　2 When used in combination with anticoagulants such as warfarin and coumarins, this drug may enhance hepatic metabolism, thereby reducing the effectiveness of these anticoagulants; therefore, it is necessary to monitor the prothrombin time in order to adjust the dose. 　　When used in combination with phenytoin and barbiturate drugs, this agent’s antifungal effect is weakened. This may be due to the fact that barbiturates reduce the absorption of this drug, and they also accelerate its inactivation by inducing liver enzymes, thereby lowering its blood concentration; therefore, the use of such drugs in conjunction with this agent should be avoided. 　　4. The use of estrogen-based contraceptives in combination with this product can reduce the effectiveness of oral contraceptives; this may be due to this product accelerating the metabolism of such drugs in the liver, resulting in lower blood drug concentrations. Their concurrent use should be avoided.

The formation mechanism of griseic acid is a very practical topic; it’s a shame that so few posts have been published on it