For many years, there was no effective treatment for human immunodeficiency virus (HIV) or AIDS (acquired immune deficiency syndrome). However, people who contract HIV today can use a variety of medications that can substantially improve their condition and quality of life. However, none of these drugs cure HIV or AIDS, some have substantial side effects and many are expensive.

Treatment aims to reduce the amount of virus in the blood to very low or even nondetectable levels. In most cases, a combination of three or more drugs – sometimes referred to as a “drug cocktail” – is used to achieve this effect, which suppresses – but does not eliminate – the virus. This suppression of the viral load will then slow down the progression to AIDS.

The main treatment for HIV and AIDS is use of anti-retroviral drugs. These are medications that inhibit the growth and replication of HIV. Such drugs include:

• Nucleoside analogue reverse transcriptase inhibitors (NRTIs). The first anti-retroviral drugs to be developed, they help keep an HIV enzyme (a protein produced by cells that acts as a catalyst in specific biochemical reactions) called reverse transcriptase from replicating.
  
  
• Protease inhibitors (PIs). Interrupt HIV replication by interfering with an enzyme known as HIV protease. Protease inhibitors cause HIV particles in the body to become structurally disorganized and noninfectious.
  
  
• Non-nucleoside reverse transcriptase inhibitors (NNRTIs). Bind directly to the enzyme reverse transcriptase.
  
  
• Nucleotide reverse transcriptase inhibitors (NtRTIs). Also interfere with the replication of reverse transcriptase and prevent the virus from inserting its genetic material into cells. NtRTIs act more quickly than NRTIs do.
  
  
• Fusion inhibitors. New drugs that appear effective against even the most drug-resistant forms of HIV. Fusion inhibitors prevent the membrane of an HIV-infected cell from fusing with the membrane surrounding healthy cells.

In certain cases, a physician may choose to change a patient’s treatment regimen. This often occurs when a patient’s drug regimen is not working well enough. Treatment changes may also be made when side effects make it difficult to take certain drugs (drug toxicity).

Since 1989, increasingly effective HIV/AIDS therapy – including a decade of highly active anti-retroviral drugs – has provided three million years of extended life to patients with AIDS in the United States, according to the National Institute of Allergy and Infectious Diseases (NIAID).