Amprenavir is primarily used in the treatment of HIV infection. It belongs to a class of drugs known as protease inhibitors, which work by blocking the activity of the HIV protease enzyme. This enzyme is essential for the virus to replicate and produce new viral particles. By inhibiting this enzyme, amprenavir helps to reduce the viral load in the body and slows the progression of the disease. It is often used in combination with other antiretroviral medications as part of highly active antiretroviral therapy (HAART) to enhance its effectiveness and reduce the risk of developing drug resistance. Amprenavir is particularly useful in managing both treatment-naïve and treatment-experienced patients, helping to improve their immune function and overall quality of life.