Delavirdine, a bisheteroarylpiperazine derivative, is a potent nonnucleoside RT inhibitor of activity specific for HIV-1. The U.S. FDA has approved this drug for use in combination with other anti-HIV agents. In Phase I/II study trials, it demonstrated sustained improvements in CD4 cell counts, p24 antigen levels, and RNA viral load. Promising results were obtained when the drug was used in two- or three-drug combinations with nucleoside drugs. Combination of delavirdine with ddI, ddC, or ZDV demonstrated additive or synergistic effects. Delavirdine with ZDV, however, was more beneficial in early HIV infection. Combinations of nevirapine and delavirdine had an antagonistic effect on HIV-1 RT inhibition.
