Crixivan is an oral medication available in 400 mg capsules, specifically designed to treat human immunodeficiency virus (HIV) infection. It can be used alone or in combination with other antiretroviral drugs. The active ingredient, indinavir, is a protease inhibitor that works by inhibiting the protease enzyme, thereby preventing the HIV virus from multiplying and spreading within the body. Crixivan is known to be effective in managing HIV and contributing to improved immune function.