HIV medications are always used in combination to reduce the amount of HIV in the blood (
viral load). They do this by helping to block or "inhibit" certain steps during the HIV
replication process.
The recommended treatment for HIV is a combination of three or more medications from two different
classes in a regimen called
Highly Active Antiretroviral Therapy (HAART). You and your healthcare provider will decide which medications are right for you.
There are four different classes or "families" of HIV medications:
- Nucleoside reverse transcriptase inhibitors (NRTIs), also called "nukes"
- Non-nucleoside reverse transcriptase inhibitors (NNRTIs), also called "non-nukes"
- Protease inhibitors (PIs)
- Fusion inhibitors (FIs), also called "entry inhibitors"
How each drug class works to fight HIV
Each class of HIV medications fights HIV in a different way. The primary difference between each class is the stage of HIV replication that the medications target.
NRTIs contain faulty versions of the building blocks (
nucleosides) used by
reverse transcriptase, an enzyme (protein) that HIV needs to make more copies of itself. When reverse transcriptase uses an NRTI instead of a normal building block, this helps to stop the replication of the virus.
NNRTIs also target reverse transcriptase, but in a different way than NRTIs do. NNRTIs help slow down HIV replication by attaching themselves to reverse transcriptase, preventing the enzyme from creating
DNA from viral
RNA.
PIs target the
protease enzyme, which cuts up long chains of genetic material into smaller pieces to complete viral replication. This is one of the final steps in the production of HIV. By helping to block protease, PIs can prevent new copies of HIV from being made.
FIs work by blocking an important step in the process of HIV entry into CD4 cells known as
fusion. By blocking fusion, FIs may prevent HIV from entering and infecting CD4 cells.
To learn more about specific HIV medications, talk to your healthcare provider.
