Taking pre-exposure prophylaxis (PrEP) “as needed” still cuts rates of HIV transmission by 86% in men who have sex with men, a study of 400 men has found. Although the medication is not currently TGA approved in Australia for indication as a prophylaxis, studies have shown that a once daily dose is highly effective […]
Taking pre-exposure prophylaxis (PrEP) “as needed” still cuts rates of HIV transmission by 86% in men who have sex with men, a study of 400 men has found.
Although the medication is not currently TGA approved in Australia for indication as a prophylaxis, studies have shown that a once daily dose is highly effective in preventing the transmission of the virus.
The research has been growing to the extent that last month, the US Centers for Disease Control and Prevention said that one in four sexually active gay and bisexual men should be on PrEP.
Surprisingly, this new study showed that even when participants were instructed to only take two ‘loading’ pills 2-24 hours prior to sex, followed by a third pill 24 hours after and another pill 24 hours later again, had almost the same level of protection as those taking it daily.
Only two participants taking PrEP as needed contracted HIV compared to 14 in the placebo group, which is “among the highest risk reductions that have been reported to date”, the authors wrote.
The findings of this study and others that have found protection when participants have detectable levels of tenofovir suggest that participants might not need continuous exposure to antiretrovirals, “especially when they are not exposed to HIV-1”.
Participants were men who were HIV-negative but considered ‘high risk’, by having unprotected anal sex with at least two partners in the last six months.
The Intervention Préventive de l’Expostion aux Risque avec et pour les Gays (IPERGAY) trial randomised participants into either a treatment group, which was given a combination of tenofovir disoproxil fumarate and emtricitabine (TDF-FTC), or the placebo group.
Everyone in the trial underwent risk reduction counselling and were given condoms.
Reassuringly, there didn’t seem to be any increase in risky sexual behaviour, in line with findings from similar studies.
Taking the pill “as needed” may offer equivalent protection to a daily dose, but improve convenience and drug adherence, the researchers said.
An accompanying perspective said political will “must be mobilized to match the scientific evidence and provide the financial and human resources necessary to dramatically scale up HIV testing and treatment around the world”.
Because the participants took an average of 15 pills per month the findings may be less applicable to men who have less frequent sex, and hence take the medication less.
PrEP use did come with an increase in gastrointestinal symptoms and a transient increase in creatine.
