Herpes simplex virus type 2 suppressive therapy with acyclovir or valacyclovir does not select for specific HIV-1 resistance in HIV-1/HSV-2 dually infected persons.

Recent in vitro studies suggest that acyclovir may directly inhibit HIV-1 replication and can select for a specific HIV-1 reverse transcriptase mutation (V75I) with concomitant loss of an anti-HIV-1 effect. We tested for HIV-1 genotypic resistance at reverse transcriptase codon 75 in plasma from 168 HIV-1-infected persons from Botswana, Kenya, Peru, and the United States taking daily acyclovir or valacyclovir for between 8 weeks and 24 months. No V75I cases were detected (95% confidence interval, 0%-2.2%). These prospective in vivo studies suggest that standard-dose acyclovir or valacyclovir does not select for HIV-1 resistance.