Nucleoside reverse transcriptase inhibitors (NRTI drugs) interfere with the production of new viruses. This is achieved by inhibiting the enzyme, reverse transcriptase. This enzyme allows the virus to copy its own RNA to produce viral DNA, which is then used to produce the virus. Without this enzyme, the virus cannot reproduce. In order to increase the effectiveness, these drugs are used in combination with one or more of the non-nucleoside reverse transcriptase inhibitors.

Examples include:

• Lamivudine (Epivir)
• Abacavir (Ziagen)
• Zidovudine (Retrovir)
• Stavudine (Zerit)
• Zalcitabine (Hivid)
• Didanosine (Videx)

Drugs that combine a nucleotide reverse transcriptase inhibitor and a protease inhibitor include:

• Emtricitabine and tenofovir disoproxil (Truvada)