There is no cure for human immunodeficiency virus (HIV) infection or acquired immunodeficiency syndrome (AIDS), but medication can prevent or slow the virus from progressing. There are several types of medications that block the virus. Each stops HIV from replicating in different ways.
NYU Langone doctors prescribe a combination of at least three medications from two or more medication classes to avoid creating strains of HIV that are resistant to treatment. This is called antiretroviral therapy.
HIV destroys CD4 cells, which are white blood cells that fight disease and infection. When the virus invades a CD4 cell, the cell is used to create new copies of HIV.
HIV does this by copying its own genetic code into the CD4 cell. The virus stores its genetic material in the form of ribonucleic acid (RNA), a molecule that transmits genetic information from deoxyribonucleic acid (DNA) to proteins produced by the cell. To infect CD4 cells, HIV must first convert its RNA into DNA. An enzyme in HIV called reverse transcriptase is necessary for this conversion.
There are three enzymes used by HIV to replicate: reverse transcriptase, protease, and integrase. The major classes of medications used to inhibit HIV replication do so by inhibiting one of these enzymes.
The following classes of antiretroviral medications can help prevent this conversion process.
Non-nucleoside reverse transcriptase inhibitors stop HIV from multiplying. They prevent the enzyme reverse transcriptase from converting RNA to DNA, which is needed for HIV to infect CD4 cells.
These medications contain faulty versions of the building blocks that HIV uses to infect CD4 cells. When the HIV enzyme reverse transcriptase uses these faulty building blocks, HIV’s genetic material cannot be inserted into the healthy cell. Interrupting this process prevents the virus from replicating in CD4 cells.
Protease inhibitors block the production of protease, a protein that HIV needs to make copies of itself in a CD4 cell.
Fusion inhibitors block HIV from entering CD4 cells. They include enfuvirtide and maraviroc.
Integrase inhibitors are given to stop the production of integrase, another protein HIV uses to insert its genetic material into CD4 cells.
People using antiretroviral therapy take these medications for the rest of their lives. They may remain in the clinical latency phase of HIV—meaning they have no symptoms or only mild ones—for several decades, because treatment suppresses the virus.
Long-term use of these medications, however, increases a person’s risk of heart attack. Doctors monitor people on antiretroviral therapy for this and other possible side effects, such as nausea, vomiting, diarrhea, and skin rashes.
You doctor conducts blood testing every three months to measure your CD4 levels and viral load, which are used to determine the amount of HIV in the blood. The goal of treatment is to return CD4 levels to normal, improving the immune system’s ability to fight infection, and to suppress the amount of virus in the blood to the point where it can’t be detected.
After HIV levels are undetectable, the doctor continues to use blood tests to check your CD4 levels every three months. Just because the viral load is undetectable, however, doesn’t mean HIV infection is cured. The virus can still be transmitted to others.
Your doctor may prescribe other medications to prevent opportunistic infections, which are infections that can result from a weakened immune system. These include pneumocystis pneumonia; cytomegalovirus disease, a common virus related to the one that causes chickenpox; and nontuberculous mycobacterial infections, a group of lung infections.
NYU Langone doctors also treat any problems related to HIV infection, such as anemia, which is caused by low levels of red blood cells, and dangerously low white blood cell levels, which may lead to infection or cancer.