Saquinavir, sold under the brand name Invirase among others, is an antiretroviral medication used together with other medications to treat or prevent HIV/AIDS. Typically it is used with ritonavir or lopinavir/ritonavir to increase its effect. It is taken by mouth. Common side effects include nausea, vomiting, diarrhea, and feeling tired. More serious side effects include problems with QT prolongation, heart block, high blood lipids, and liver problems. It appears to be safe in pregnancy. It is in the protease inhibitor class and works by blocking the HIV protease. Saquinavir was patented in 1988 and first sold in 1995. Source: Wikipedia (en)