adefovir dipivoxil + indinavir + zidovudine + lamivudine

This is a **four-drug oral antiretroviral combination** comprised of adefovir dipivoxil, indinavir, zidovudine, and lamivudine. - **Adefovir dipivoxil** is a prodrug of adefovir, an acyclic nucleotide analog that is intracellularly converted to adefovir diphosphate, which inhibits viral DNA polymerase and causes DNA chain termination. It is active against hepatitis B virus (HBV) and shows activity against HIV and several other viruses[1][3][5]. - **Indinavir** is a protease inhibitor that inhibits HIV-1 and HIV-2 proteases, resulting in production of immature, noninfectious viral particles[2][4]. - **Zidovudine (AZT)** is a nucleoside reverse transcriptase inhibitor (NRTI), acting as a thymidine analog, competitively inhibiting viral reverse transcriptase and causing DNA chain termination[2][4]. - **Lamivudine (3TC)** is a cytidine analog NRTI, inhibiting reverse transcriptase by both competitive inhibition and chain termination[2][4]. This combination targets multiple steps in HIV replication, providing synergistic suppression and lowering resistance risk. Triple therapy with indinavir, zidovudine, and lamivudine has shown durable suppression of HIV RNA and improved CD4 counts in clinical studies; adefovir has documented anti-HIV activity but is not a standard HIV therapy[2][4][1]. The combination, as listed, is not a marketed fixed-dose product but represents a multi-agent regimen for research or off-label use.