Research indicates success in varied methods of taking PrEP

Morgan Liotta

3/04/2019 1:47:53 PM

Following news of a man contracting HIV while on the preventive drug, newsGP talks to a sexual health physician about different approaches to taking the medication.

PrEP pill
Taking the PrEP pill has shown to significantly decrease HIV risk.

News of a second Australian man recently contracting HIV despite taking the HIV-prevention medicine pre-exposure prophylaxis (PrEP) may have cast some doubts about the success of the drug.
But Dr Vincent Cornelisse, a GP and expert in HIV prevention, who recently won the 2019 Premier’s Public Health Research Award for his research on sexual health and PrEP, told newsGP that PrEP’s efficacy remains strong.
‘It’s understandable for people to feel concerned by news that someone has contracted HIV despite taking PrEP,’ Dr Cornelisse said.
‘However, this case does not change that we have strong evidence to show that PrEP is highly effective at preventing HIV, as shown in randomised placebo-controlled trials and open label studies.
‘Unfortunately, no HIV-prevention strategy is 100% effective, but PrEP comes pretty close, and it is certainly the most effective prevention strategy currently available.’
The newly diagnosed HIV-positive man, Steve Spencer, was a very early adopter and strong advocate of PrEP, and is ‘very brave in going public with his diagnosis,’ according to Dr Cornelisse.
Mr Spencer was taking PrEP ‘on demand’, which Dr Cornelisse said is included in Australian PrEP guidelines as an alternative to taking the medication daily, based on results from early trials that he compared.
‘The on-demand method of taking PrEP was studied in several trials in Europe, which was a randomised placebo-controlled trial, and its open-label extension,’ he said.
‘The on-demand method used consisted of [taking] two PrEP pills at least two hours before sex, followed by one pill 24 hours later and another pill 48 hours after the initial dose.
‘So this means that participants took four PrEP pills around one episode of sex, which is in contrast to [taking] daily PrEP, where people take one PrEP pill every day on an ongoing basis.’
Dr Vincent Cornelisse looked at trials comparing methods of taking PrEP as part of his sexual health research.

These trials found participants who took on-demand PrEP had an 86% lower risk of HIV than participants who took placebo, and the open-label extension found that on-demand PrEP conferred a 97% reduction in HIV risk.
Dr Cornelisse believes that although cases such as this can prompt fresh doubts about the medication, GPs are in a sound position to reassure and educate patients who are taking PrEP, or thinking about starting it.
‘It is important to keep things in perspective. Understandably, some PrEP users will be anxious about the news that a fellow PrEP user has contracted HIV,’ he said.
‘But hopefully this anxiety can be assuaged by reminding them that there are less than a handful of well-documented cases where people have contracted HIV while being adherent to PrEP, despite hundreds of thousands of people around the world now relying on PrEP to protect themselves against HIV.
‘If you look at these numbers, it is pretty obvious that PrEP has prevented countless cases of HIV.’
People living with HIV in Australia have reportedly experienced a decrease in the stigma attached and a sense of liberation in their sexual relationships, which Dr Cornelisse believes can be credited to robust collaboration between healthcare professionals and the community.
‘HIV rates are decreasing rapidly ... and we should celebrate this as a success,’ he said.

HIV prevention pre-exposure prophylaxis PrEP research sexual health

newsGP weekly poll Would you be willing to provide a firearms health assessment for your patient?


Login to comment

Dr Matthew Long   4/04/2019 5:17:31 PM

What's the data on PrEP daily intake vs on demand? By "at least 2 hours before sex " do you take it before you go out? Is the morning of a night time encounter OK?

Vincent Cornelisse   9/04/2019 10:34:24 AM

Thanks Dr Long,
First part: There is no head-to-head comparison data of daily PrEP vs on-demand PrEP
Second part: the Australian PrEP guidelines state ‘IPERGAY evaluated the efficacy of an on-demand regimen comprising two pills of TDF/FTC (vs placebo) taken 2–24 hours before potential sexual exposure to HIV, followed by one pill daily until 48 hours had passed after the last act of sexual intercourse. If sexual activity is resumed within a week, a single, rather than a double, dose before sex was recommended. If sexual activity resumed more than a week later, the loading dose schedule (2 tablets) was recommenced, followed by one pill daily until 48 hours had passed after the last act of sexual intercourse’
ASHM’s PrEP resources –
Australian PrEP guidelines –,_Viral_Hepatitis_and_Sexual_Health_Medicine_HIV_pre-exposure_prophylaxis:_clinical_guidelines._Update_April_2018