Fusidic acid, metabolic effects

FUSIDIC ACID ANTIVIRALS-PROTEASE INHIBITORS Possibly t adverse effects Inhibition of CYP3A4-mediated metabolism of fusidic acid Avoid co-administration... 

Activation of the CYP450 enzyme system, demonstrated by an increase in the metabolism of phenazone (antipyr-ine), has been found in 30 HIV-positive drug abusers (24). This activating effect was demonstrated after 28 but not after 14 days of treatment with fusidic acid 500 mg/day, suggesting time dependency. 

Investigation of the metabolic effects of fusidic acid in man [334] have shown that, like the tetracycline group, it has a mild catabolic effect upon protein metabolism. It also shows a hypocalciuric effect and a moderate reduc-tion in bromsulphthalein excretion, with the latter probably arising from a competition between the metabolites of fusidic acid and the bromsulphthalein for a common transport mechanism involved in the excretion into the bile. Seven such metabohtes of fusidic acid have been isolated from human bile [335]. 

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