When AIDS first surfaced in the United States, there were no medicines to combat the underlying immune deficiency and few treatments existed for the opportunistic diseases that resulted. During the past 10 years, however, researchers have developed drugs to fight both HIV infection and its associated infections and cancers.
The U.S. Food and Drug Administration (FDA) has approved a number of drugs for treating HIV infection. The first group of drugs used to treat HIV infection, called nucleoside reverse transcriptase (RT) inhibitors, interrupts an early stage of the virus making copies of itself. Included in this class of drugs (called nucleoside analogs) are AZT, ddC (zalcitabine), ddI (dideoxyinosine), d4T (stavudine), 3TC (lamivudine), abacavir (ziagen), and tenofovir (viread). These drugs may slow the spread of HIV in the body and delay the start of opportunistic infections.
Health care providers can prescribe non-nucleoside reverse transcriptase inhibitors (NNRTIs), such as delvaridine (Rescriptor), nevirapine (Viramune), and efravirenz (Sustiva), in combination with other antiretroviral drugs.
FDA also has approved a second class of drugs for treating HIV infection. These drugs, called protease inhibitors, interrupt virus replication at a later step in its life cycle. They include
- Ritonavir (Norvir)
- Saquinivir (Invirase)
- Indinavir (Crixivan)
- Amprenivir (Agenerase)
- Nelfinavir (Viracept)
- Lopinavir (Kaletra)
Because HIV can become resistant to any of these drugs, health care providers must use a combination treatment to effectively suppress the virus. When RT inhibitors and protease inhibitors are used in combination, it is referred to as highly active antiretroviral therapy, or HAART, and can be used by people who are newly infected with HIV as well as people with AIDS.
Researchers have credited HAART as being a major factor in significantly reducing the number of deaths from AIDS in this country. While HAART is not a cure for AIDS, it has greatly improved the health of many people with AIDS and it reduces the amount of virus circulating in the blood to nearly undetectable levels. Researchers, however, have shown that HIV remains present in hiding places, such as the lymph nodes, brain, testes, and retina of the eye, even in patients who have been treated.
Despite the beneficial effects of HAART, there are side effects associated with the use of antiviral drugs that can be severe. Some of the nucleoside RT inhibitors may cause a decrease of red or white blood cells, especially when taken in the later stages of the disease. Some may also cause inflammation of the pancreas and painful nerve damage. There have been reports of complications and other severe reactions, including death, to some of the antiretroviral nucleoside analogs when used alone or in combination. Therefore, health care experts recommend that people on antiretroviral therapy be routinely seen and followed by their health care providers. The most common side effects associated with protease inhibitors include nausea, diarrhea, and other gastrointestinal symptoms. In addition, protease inhibitors can interact with other drugs resulting in serious side effects.
A number of drugs are available to help treat opportunistic infections to which people with HIV are especially prone. These drugs include
- Foscarnet and ganciclovir to treat cytomegalovirus (CMV)eye infections
- Fluconazole to treat yeast and other fungal infections
- Trimethoprim/sulfamethoxazole (TMP/SMX) or pentamidine to treat Pneumocystis carinii pneumonia (PCP)
