Voriconazole NNRTIs

FLUCONAZOLE, VORICONAZOLE NNRTIs Possible 1 efficacy of azole t CYP3A4-mediated metabolism Avoid co-administration... 

Drugs affected by voriconazole include the following benzodiazepines, calcium channel blockers, cisapride, coumarin anticoagulants, cyclosporine, ergot alkaloids, HMG-CoA reductase inhibitors, NNRTIs, phenytoin, protease inhibitors, pimozide, proton pump inhibitors, quinidine, prednisolone, rifabutin, sirolimus, sulfonylureas, tacrolimus, vinca alkaloids. 

Coadministration with rifampin, rifabutin, or ritonavir is contraindicated because of accelerated voriconazole metabolism. Efavirenz and perhaps other normucleoside reverse transcriptase inhibitors (NNRTIs) significantly increase voriconazole metabolism and slow the metabolism of the NNRTI. When given with phenytoin, the voriconazole dose should be doubled. Drugs that significantly accumulate in patients receiving voriconazole include cyclosporine,... 

The metabolism of voriconazole by the cytochrome P450 isoenzyme C YP3A4 is induced by efavirenz. Nevirapine is predicted to interaet similarly, whereas delavirdine is predicted to inhibit the metabolism of voriconazole. All the NNRTIs are substrates of CYP3A4, which is inhibited by voriconazole. 

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