stavudine + didanosine + indinavir

This is a fixed combination regimen of three antiretroviral drugs: **stavudine**, **didanosine**, and **indinavir**. Each drug is a small molecule acting on HIV-1 replication via distinct targets: - **Stavudine** and **didanosine** are nucleoside reverse transcriptase inhibitors (NRTIs), which inhibit HIV-1 reverse transcriptase by incorporation into viral DNA and causing chain termination. - **Indinavir** is a protease inhibitor, which blocks the action of HIV-1 protease, preventing cleavage of viral polyproteins and resulting in the production of immature, noninfectious virus. This triple regimen has been studied for the treatment of HIV-1 infection, showing potent antiretroviral activity marked by reductions in plasma HIV RNA and increases in CD4+ lymphocyte counts in both adults and children[2][4][5][6]. However, significant toxicity, including fatal lactic acidosis (especially in pregnant individuals) and pancreatitis, has also been observed[1][3][4].