Pre-exposure prophylaxis involves the use of antiviral treatments regularly or before and after possible HIV exposure events to decrease the risk of acquiring HIV infection.
Studies show that in populations at increased HIV infection risk, preexposure chemoprophylaxis for HIV is associated with decreased risk of acquiring HIV infection, and the results vary according to the level of adherence.
In trials in which adherence to PREP was 70% or greater, the reduction in risk is approximately 75%.
In a randomly assigned group of 2499 HIV seronegative men or trans gender women to receive the combination of emtricitabine and tenofovir disoproxil fumarate or placebo daily: subjects followed for 3324 person-years, resulted in a 44% reduction in the incidence of HIV in the treatment group, And detectable blood levels strongly correlated with prophylactic effect (Grant RM et al).
Daily preexposure prophylaxis with 300 mg of tenofovir disoproxil fumatate alone or in combination with 200 mg of emitricitabine reduces the risk of acquisition of HIV BY 50% or more among infividuals with high adherence to the treatment.
Effective in preventing HIV infection in men who have sex with men, as well as heterosexual men and women.
Reduces infections between 44 and 75%, and is much is 90% when analysis of patients had detectable drug levels, indicating compliance.
Studies find 100% protection for patient’s with sustained adherence at a level of four or more doses per week.
In 2017 the CDC estimated that 1.1 million people in the US met the criteria for preexposure chemoprophylaxis for for HIV, yet only about 100,000 used preexposre prophylaxis.
HIV pre-exposure prophylaxis is highly effective in reducing HIV acquisition risk among gay and bisexual men who have high medication adherence.
Patients with use of HIV pre-exposure prophylaxis is associated with an increased risk of sexually transmitted infections among individuals with high risk HIV infection.