Protease inhibitors are a type of antiviral pharmaceutical designed to fight HIV/AIDS and hepatitis C. Protease inhibitors prevent the virus from replicating by binding to the virus’ proteases and blocking the proteins responsible for virus replication.
The first protease inhibitor approved by the FDA in 1995 was Saquinavir, known by the trade names Fortovase and Invirase. Other protease inhibitors include Norvir, Cirixivan, Viracept, Agenarase, Kaletra, Aptivus, and Prezista. As with any drugs that specifically target a virus, much like antibiotics, there is a risk of drug-resistance developing. In order to reduce this risk, these drugs are usually given in combination, called a drug cocktail.
A protease is an enzyme, found in animals, plants, bacteria, archea and viruses. They initiate protein catabolism, breaking down molecules into smaller units in order to release energy. HIV is a retrovirus that attacks the human immune system, largely through CD4+ T cells.
It was David Ho who pioneered the use of protease inhibitors in combatting HIV/AIDS. There are known side effects to protease inhibitors, including lipodystrophy (loss of fat cells in the face), hyperlipidaemia (elevated lipids in the blood), type 2 diabetes, and kidney stones. However, protease inhibitors are also being employed to fight cancer, Chagas disease and malaria.