Pharmacological interactions with darunavir

Darunavir is a new HIV protease inhibitor that has been shown to be highly useful in HIV-infected patients. This drug is primarily metabolized by the liver through the cytochrome P450 3A4 (CYP3A4) isozyme and consequently coadministration with low doses of ritonavir markedly increases exposure and allows both daily doses and pill burden to be reduced. Both darunavir and ritonavir act as inhibitors and substrates of CYP3A4 and may therefore present pharmacological interactions with a large number of drugs commonly used in HIV-infected patients. The present review aims to summarize the main studies that have evaluated drug interactions and to provide recommendations on treatment with darunavir/ritonavir in clinical practice.