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In the early 1980s when the epidemic began, AIDS patients were not likely to live longer than a few years. With the development of safe and effective drugs, however, people infected with HIV now have longer and healthier lives.
The antiretroviral medications used to treat HIV/AIDS currently are organized into five major drug classes:
Reverse transcriptase (RT) inhibitors
These inhibitors interfere with the reverse transcriptase which converts HIV RNA to HIV DNA. There are two main types of RT inhibitors: nucleoside/nucleotide and non-nucleoside. The non-nucleoside RT inhibitor works by interfering with the enzyme's catalytic ability. The nucleoside/nucleotide RT inhibitors are analogues of the natural deoxynucleotides needed to synthesize the viral DNA. Their deoxyribose lacks a 3'-hydroxyl group, which is required to form the 5'-3' phosphodiester bond in a DNA chain. Therefore, after a nucleoside/nucleotide RT inhibitor is incorporated into the growing HIV DNA chain during the reverse transcription process, the DNA chain cannot be extended further. Without a complete DNA, HIV replication is blocked.
Protease is an enzyme that HIV uses to cut precursor proteins (gag and pol) into smaller functional proteins. The protease inhibitor works by binding to the enzyme's active center.
They interfere with the virus' ability to fuse with the cellular membrane, thereby blocking entry into the host cell.
They block integrase, the enzyme HIV uses to integrate genetic material of the virus into its target host cell.
Multidrug Combination Products
A single product contains more than one class of drugs. To combat virus strains from becoming resistant to specific antiretroviral drugs, healthcare providers recommend that people infected with HIV take a combination of antiretroviral drugs known as highly active antiretroviral therapy (HAART).