PrEP is the first biomedical prevention strategy that enables gay and bisexual men (including trans men) and trans women to effectively take charge of their own HIV risk.
With good adherence, PrEP is highly effective, and typical use of PrEP is more effective than typical use of condoms. This is not surprising when you consider that a PrEP pill can be taken in the morning with breakfast, at a time when people are usually clear-headed, whereas the effectiveness of condoms relies on a person using a condom during sex, a time when they may be intoxicated or otherwise excited, or just do not happen to have a condom at hand. In some cases, a person may be in a situation where they cannot exercise their right to use a condom.
Concerns have been raised that PrEP use will result in a reduction in condom use and an increase in STIs. Some risk compensation is likely to occur, but it’s important that we keep our eyes on the prize: San Francisco has seen a 50% drop in new HIV infections since PrEP was approved by the US Food and Drug Administration in 2012, and we now have the opportunity to achieve similar reductions in Australia.
PrEP also provides an incentive for patients to return for 3-monthly STI screens, as recommended by the Australian STI guidelines, which should help efforts to control STIs. At the same time, regular PrEP appointments provide an opportunity to screen for mental health difficulties and problems from the use of alcohol and drugs, and these problems disproportionately affect the same groups of people who may benefit from PrEP.
Another concern is that increased use of PrEP may result in more people acquiring antiretroviral-resistant strains of HIV, which would limit their HIV treatment options. This has been observed in PrEP trials, but mainly when people started PrEP when they were already HIV-positive. This highlights the importance of ensuring that people are HIV-negative when they start PrEP, and that they have 3-monthly HIV tests during PrEP use, to minimise their exposure to PrEP if they do acquire HIV.
Prescribers should also keep in mind that those without a Medicare card (eg, overseas students) can be assisted to access PrEP under the TGA’s personal importation scheme.
Dr Vincent Cornelisse
BSc(Hons) MBBS FRACGP FAChSHM
Sexual health physician, Melbourne, Victoria