 Pravastatin Pravachol is approved by the Food and Drug Administration FDA and is used to treat high cholesterol. Darunavir Prezista and ritonavir Norvir are approved by the Food and Drug Administration FDA to treat HIV infection. When darunavir and ritonavir are given with pravastatin, they can increase the blood levels of pravastatin. The degree of this interaction varies from person to person. The way that darunavir and ritonavir interact with pravastatin may be affected by a persons genetic make-up. Genetic factors or DNA are those that people are born with and that make each person unique. Genetic differences are the reason why one persons body traits such as height and hair color are different from another persons body traits. Genetic differences can also affect the way a medication works in the body or the way two medications interact in the body. The purpose of this clinical study is to determine if a persons genetic make-up affects the way darunavir and ritonavir interact with pravastatin in the body. 