Characterization of oxyphenarsine as a potential antiviral agent for AIDS.

The historical antisyphilis drug oxyphenarsine has been tested for antiviral activity and for cytotoxicity to characterize it as a potential therapy for treatment of HIV infections. These data show that the compound demonstrates marginal antiviral activity against the HTLV-IIIB strain of HIV-1, two clinical isolates of HIV-1 (one sensitive to AZT and one resistant), and the MS strain of HIV-2. However, treatment with concentrations of oxyphenarsine showing optimal anti-HIV activity resulted in significant cytotoxicity. The drug's selectivity index was not significantly improved when tested against H9 cells chronically infected with the HTLV-IIIB strain of HIV-1. Thus, despite a previous report suggesting significant antiviral activity and low cytotoxicity for oxyphenarsine, the data presented here do not provide support for further development of this drug as an anti-HIV agent.