Media Release

22 March 2019

The Australasian Society for HIV, Viral Hepatitis and Sexual Health Medicine (ASHM) has highlighted Australia’s guidelines regarding the use of “on-demand” PrEP for preventing HIV, following the recent HIV diagnosis of a high-profile PrEP advocate in Sydney.

ASHM is the author of Australia’s clinical guidelines on the use of HIV pre-exposure prophylaxis (PrEP), a HIV-prevention method that involves a HIV-negative person taking a daily dose of a specific HIV medication to prevent them from contracting the virus. Daily PrEP may offer close to 100 per cent efficacy at preventing HIV when used with high medication adherence, and is supported by a significant body of clinical evidence.

An alternative method for PrEP is “on-demand” use, which involves taking the medication only around the time of sexual activity: two pills taken 2–24 hours before potential sexual exposure to HIV, followed by one pill daily until 48 hours have passed after the last act of sexual intercourse.

ASHM Clinical Adviser Darren Russell, who sits on the committee that reviews the PrEP clinical guidelines, said there are a number of reasons someone might want to choose on-demand PrEP.

“Taking PrEP only around the time of sexual events allows for fewer tablets to be taken overall, resulting in less exposure to medication, potentially fewer side-effects, and lower costs,” Russell said.

“There is a body of evidence to support the use of on-demand PrEP, and it is estimated that tens of thousands of people around the world are choosing to take PrEP on-demand rather than daily.”

Russell continued: “When it comes to daily PrEP use, there are only a very small handful of well-verified cases worldwide where an individual has acquired HIV while taking PrEP daily as prescribed. It is important to remember that while PrEP is highly effective at preventing HIV, like any other HIV-prevention method it is not 100 per cent effective. If you have any questions or concerns about on-demand PrEP, please speak with your clinician.”

The HIV diagnosis of a high-profile PrEP advocate reported today in the Star Observer has prompted community discussions about the efficacy of PrEP, and on-demand PrEP in particular.

ASHM CEO Alexis Apostolellis said it was important to remind clinicians and the wider community that Australia’s clinical guidelines on the use of PrEP are evidence-based.

“All clinical guidelines produced by ASHM go through a rigorous development and review process, with input from some of the world’s top researchers and clinicians,” Apostolellis said.

“Clinicians need to understand the latest evidence to keep up with how a HIV-prevention method like PrEP is actually being used by the community, and our guidance on PrEP represents best-practice in evidence-based clinical guidelines.”