Can Anti-HIV Medications Prevent HIV Infection in Heterosexuals?
The study was conducted in Botswana to evaluate if pretreatment with Anti-HIV medications tenofovir disoproxil fumarate and emtricitabine reduced the transmission of HIV in a heterosexual population. Botswana has the second highest prevalence of HIV in the world. Thus, any additional preventive measure could play an important role in controlling HIV infection in this country.
The 1219 participants included in the study were sexually active adults between 18 to 39 years of age who tested negative for HIV and hepatitis B infection. Most of the participants had only one sexual partner in the previous month. They were provided either tenofovir disoproxil fumarate and emtricitabine, or a placebo for comparison of effect. The participants were not aware whether they received an active medication or placebo. They were also provided HIV preventive services like counseling and free condoms and were followed up monthly.
The study found that the combination of tenofovir disoproxil fumarate and emtricitabine decreased HIV infection by 62.2% when it was administered as part of a comprehensive package of HIV-prevention services. Ten participants were infected with HIV among those taking the medication and 26 among those on placebo. The patients who developed HIV despite the medication had lower drug levels compared to those who did not develop the infection. This suggests that they possibly were not strictly compliant with their medication intake.
Side effects like nausea, vomiting and dizziness were more common in the group that took medication. Bone mineral density appeared to be significantly decreased in some individuals on the medication.
Drug resistance was noted in a participant who had unrecognized HIV infection and was administered the medication. Hence, it is necessary to screen people carefully before they are administered preventive Anti-HIV medication.
People taking medication to prevent HIV could possibly become more promiscuous. Though this was not observed in the current study, this fact should be borne in mind when a person is put on preventive medications for HIV.
The study thus concluded that a combination of the Anti-HIV medications, tenofovir disoproxil fumarate and emtricitabine, prevented HIV infection among heterosexual men and women. Further studies are necessary to establish the use of these medications for preventing HIV infection.
Antiretroviral Preexposure Prophylaxis for Heterosexual HIV Transmission in Botswana; Michael Thigpen et al; July 11, 2012 (10.1056/NEJMoa1110711)