Use of postexposure prophylaxis against HIV infection following sexual exposure does not lead to increases in high-risk behavior.

Background: The effectiveness of postexposure prophylaxis (PEP) following occupational exposure to HIV has prompted advocacy for PEP following sexual or drug-use exposures.

Objective: To evaluate the concern that the availability of PEP for sexual or drug-use exposures might result in behavioral disinhibition.

Design: Non-randomized trial of 397 adults with high-risk sexual or drug-use exposures within the prior 72 h.

Interventions: Antiretroviral medication for 4 weeks and five counseling sessions.

Main Outcome Measurements: Participants were followed for 12 months for repeat request for PEP and for changes compared with pre-enrollment in overall high-risk behavior and the acquisition of sexually transmitted diseases (STD) and HIV.

Results: After 12 months following receipt of PEP, the majority of participants (83%) did not request a repeat course of PEP. At 12 months after exposure, 73% of participants reported a decrease compared with baseline in the number of times they had performed high-risk sexual acts; 13% reported no change, and 14% had an increase. Most participants (85%) had no change in the incidence of STD; 8.5% had a decrease and 6.8% an increase. Three homosexual men seroconverted for HIV (none associated with the presenting exposure) for a rate of 1.2/100 person-year, equivalent to rates in San Francisco among all homosexual men.

Conclusions: After receipt of PEP consisting of antiretroviral medication and behavioral counseling following a potential sexual exposure to HIV, most individuals do not increase high-risk behavior. Coupled with prior safety and feasibility data, this lack of behavioral disinhibition suggests that use of PEP should be routinely considered following high-risk sexual exposures.