Maraviroc Ketoconazole

Atazanavir, atazanavir/ritonavir, lopinavir/ritonavir and saquinavir markedly increased the AUC of maraviroc by about three to fivefold in healthy subjects. Ritonavir-boosted saquinavir had an even greater effect (alraut tenfold). In contrast, tiprana-vir/ritonavir had no effect. Ketoconazole caused a fivefold increase. The manufacturer su ests that the dose of maraviroc should be halved when used with protease inhibitors. 

Ketoconazole 400 mg once daily increased the AUC and maximum level of maraviroc 100 mg twice daily by fivefold and 3.4-fold, respectively, in... 

Maraviroc is a substrate of the cytochrome P450 isoenzyme CYP3A4 of which most protease inhibitors and ketoconazole are potent inhibitors. 

Drug-drug interactions Maraviroc is a substrate of P glycoprotein and CYP3A4, by which it is about 65% metabolized. Maraviroc should therefore be used with caution when inhibitors of CYP3A4 are used concomitantly. Potent CYP 3A4 inhibitors, such as ketoconazole and protease inhibitors, except tipranavir + ritonavir, increase maraviroc exposure dosage reduction can compensate [246 ]. Conversely, enzyme inducers, such as rifampicin and efavirenz, reduce exposure [247 ]. In contrast, drugs... 

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