What nucleoside reverse transcriptase inhibitor is included in the drug Combivir?

Combivir is a fixed-dose combination antiretroviral medication that is primarily used in the treatment of HIV infection. It contains two active ingredients: zidovudine (AZT), a nucleoside reverse transcriptase inhibitor (NRTI), and lamivudine (3TC), which is also an NRTI. Lamivudine is specifically recognized for its effectiveness in inhibiting the reverse transcriptase enzyme of the HIV virus, thereby preventing the virus from replicating and reducing viral load in patients.

The mechanism of action of lamivudine involves its incorporation into the viral DNA chain during the replication process, which leads to premature termination of the DNA strand. This action is crucial for the management of HIV infection, as it helps to suppress the viral load and improve immune function in infected individuals.

Considering the other options, rifampin and isoniazid are antibiotics used primarily for treating bacterial infections, such as tuberculosis, and do not have any role in HIV treatment. Tenofovir, while another NRTI used in HIV therapy, is not a component of Combivir; it is usually part of other combination regimens. Therefore, lamivudine stands out as the correct answer precisely because it is one of the