Ritonavir, sold under the brand name Norvir, is an antiretroviral medication used along with other medications to treat HIV/AIDS. This combination treatment is known as highly active antiretroviral therapy (HAART). Ritonavir is a protease inhibitor and is used with other protease inhibitors. It may also be used in combination with other medications to treat hepatitis C. It is taken by mouth. Tablets of ritonavir are not bioequivalent to capsules, as the tablets may result in higher peak plasma concentrations.Common side effects include nausea, vomiting, loss of appetite, diarrhea, and numbness of the hands and feet. Serious side effects include liver problems, pancreatitis, allergic reactions, and arrythmias. Serious interactions may occur with a number of other medications including amiodarone and simvastatin. At low doses it is considered to be acceptable for use during pregnancy. Ritonavir is of the protease inhibitor class. Typically, however, it is used to inhibit the enzyme that metabolizes other protease inhibitors. This inhibition allows lower doses of these latter medications to be used.Ritonavir was patented in 1989 and came into medical use in 1996. It is on the World Health Organizations List of Essential Medicines. Ritonavir capsules were approved as a generic medication in the United States in 2020. Medical uses
Ritonavir is indicated in combination with other antiretroviral agents for the treatment of HIV-1-infected patients.In December 2021, the combination of nirmatrelvir and ritonavir was granted emergency use authorization by the US Food and Drug Administration (FDA) for the treatment of coronavirus disease COVID-19.
The compromised oral bioavailability of the drug led to temporary removal of the oral capsule formulation from the market. As a consequence of the fact that even a trace amount of form II can result in the conversion of the more bioavailable form I into form II, the presence of form II threatened the ruin of existing supplies of the oral capsule formulation of ritonavir; and indeed, form II was found in production lines, effectively halting ritonavir production. Abbott (now AbbVie) withdrew the capsules from the market, and prescribing physicians were encouraged to switch to a Norvir suspension. It has been estimated that Abbott lost more than $250 million USD as a result, and the incident is often cited as a high-profile example of disappearing polymorphs.The companys research and development teams ultimately solved the problem by replacing the capsule formulation with a refrigerated gelcap. In 2000, Abbott (now AbbVie) received FDA-approval for a tablet formulation of lopinavir/ritonavir (Kaletra) which contained a preparation of ritonavir that did not require refrigeration. Ritonavir produced in a solid dispersion by melt-extrusion was found to remain in form I, and was re-introduced commercially in 2010. Society and culture
Economics
In 2003, Abbott (AbbVie, Inc.) raised the price of a Norvir course from US$1.71 per day to US$8.57 per day, leading to claims of price gouging by patients groups and some members of Congress.