Indinavir is an antiretroviral drug used to treat human immunodeficiency virus (HIV) and acquired immunodeficiency syndrome (AIDS). This medication is of a type called a protease inhibitor, which means that it inhibits the activity of a viral enzyme called a protease. Indinavir is used in conjunction with other antiretroviral drugs in a type of therapy called highly active antiretroviral therapy (HAART). In addition to being used as an HIV treatment, HAART is used as a preventative measure for healthcare workers who are at risk of HIV exposure.
Proteases are enzymes that break down proteins, and they are naturally present in all life forms, including plants and single-cell organisms. For retroviruses such as the human immunodeficiency virus, they are essential for replication. When HIV protease activity is blocked, virus particles no longer can make new copies of themselves.
Indinavir can cause a range of common and rare side effects. The most common side effects are stomach pain and headaches. These normally are minor, but if they are severe, they should be reported to a doctor. Another common side effect is lipodystrophy, also known as body fat redistribution. This means that body fat can be reduced in some areas of the body, such as the face or breasts, and increased in other areas. Metabolic disorders such as high triglyceride or high cholesterol levels also can develop.
People who take this antiretroviral drug have an increased risk of developing kidney stones. To combat this risk, it is important for them to drink plenty of water — six or seven 8-ounce glasses per day (about 1.5 liters per day) is recommended. Many protease inhibitors also can increase the risk of developing diabetes. Symptoms of diabetes, such as unintended weight loss, excessive hunger and thirst, frequent urination and fatigue tend to develop two to three months after the medication is first taken.
One of the greatest drawbacks in using indinavir to treat HIV infection is that this medication has a very short half-life. This term refers to the rate at which the drug is metabolized by the body or excreted. The short half-life of this drug means that the timing of doses must be very precise; each dose must be taken at intervals of exactly eight hours. This is necessary to prevent the virus from mutating into a form that might be resistant to the drug.
The development of protease inhibitor drugs in the 1990s was a significant improvement in the field of HIV and AIDS treatment, improving the quality of life as well as the lifespan of people with AIDS. Although indinavir can suppress viral replication, however, it cannot eradicate the virus completely. Therefore, it is not able to cure the disease. In addition, someone who is infected with HIV still is capable of transmitting the virus even when taking the drug.