Simvastatin Rifampicin

Rifampicin greatly reduced the plasma concentrations of simvastatin and simvastatin acid in 10 healthy volunteers in a randomized, crossover study (57). Because the half-life of simvastatin was not affected by rifampicin, induction of CYP3A4-mediated first-pass metabolism of simvastatin in the intestine and liver probably explains this interaction. 

STATINS RIFAMPICIN Rifampicin may lower fluvastatin and simvastatin levels Uncertain Monitor lipid profile closely look for poor response to fluvastatin and simvastatin... 

In healthy snbjects taking rifampicin the and AUC of simvastatin were greatly rednced (127), presnmably by enzjmie indnction. It is likely that other HMG-CoA reductase inhibitors, inclnding lovastatin and... 

CYP3A4 alprazolam, calcium channel blockers, cisapride, clarithromycin, cyclosporin A, erythromycin, HIV protease inhibitors, lidocaine, midazolam, simvastatin, terfenadine carbamazepine, dexamethsone, phenobarbital, phenytoin, rifampicin, St John s wort cimetidine, erythromycin, grapefruit juice, HIV protease inhibitors, itraconazole, ketoconazole... 

Rifampicin lowers the serum levels of atorvastatin, fluvastatin, pravastatin, and simvastatin. 

Especially the inhibition or induction of cytochrome P450 subtype 3A4 (CYP 3A4) is clinically relevant, because a variety of active substances and food substances (e.g. grapefruit juice) are able to affect this enzyme. Substances inhibiting CYP 3A4 include ciclosporin, dihydropyridines, verapamil, midazolam, paclitaxel, simvastatin, lovastatin, atorvastatin, cimetidine, erythromycin, troleandomycin, ketoconazole (and other azoles). Substances inducing CYP 3A4 include steroids, rifampicin, phenobarbital and St John s wort. 

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