Protease inhibitors are a class of antiviral drugs that block the action of proteases, enzymes that play a crucial role in the replication of viruses, particularly in the case of HIV. By inhibiting these enzymes, protease inhibitors prevent the virus from maturing and multiplying, helping to control the infection. These medications are often used in combination with other antiretroviral drugs to enhance their effectiveness. Common examples of protease inhibitors include Ritonavir, Lopinavir, and Atazanavir. They are an essential part of treatment regimens for individuals living with HIV/AIDS, improving their quality of life and reducing the risk of transmission.