Ritonavir (Norvir)

Ritonavir (Norvir) is a protease inhibitor, an anti-HIV drug that reduces the amount of virus in the body. Anti-HIV drugs such as ritonavir slow down or prevent damage to the immune system, and reduce the risk of developing AIDS-related illnesses. Protease (or proteinase) is the enzyme that HIV uses to break up large viral proteins from which new HIV particles can be made. For more information about how protease inhibitors work, see Protease inhibitors.

Ritonavir was approved for use in combination with nucleoside reverse transcriptase inhibitors (NRTIs) for treating adults with advanced or progressing HIV disease in Europe and the United States in late 1996 .

Ritonavir is manufactured by Abbott, under the trade name Norvir. During early trials it was known as ABT-538 and A-84,538. A generic version of the drug is manufactured by Hetero/Genix under the trade name Ritovir.

Although it was originally developed for use as a protease inhibitor in its own right, today ritonavir is mainly used in low doses to boost the effect (blood levels) of one of the other protease inhibitors.