delavirdine + zidovudine

Delavirdine + zidovudine is a combination of two antiretroviral drugs used primarily in the treatment of HIV-1 infection. **Delavirdine** is a bisheteroarylpiperazine and acts as a non-nucleoside reverse transcriptase inhibitor (NNRTI) by binding directly to HIV-1 reverse transcriptase and inhibiting its activity, thus blocking viral RNA-dependent and DNA-dependent DNA polymerase activities. **Zidovudine** is a nucleoside reverse transcriptase inhibitor (NRTI) which is incorporated into viral DNA by reverse transcriptase, causing chain termination and inhibition of viral replication. The combination was studied for synergistic or additive antiviral activity against HIV-1. Resistance to delavirdine develops rapidly when used as monotherapy or in dual therapy, but the combination initially shows enhanced antiviral effects.