by Liz Highleyman

Educating clients at a San Francisco sexual health clinic about on-demand pre-exposure prophylaxis (PrEP) increased their desire to use the intermittent HIV prevention method, researchers reported this week at the 23rd International AIDS Conference (AIDS 2020: Virtual). Among the 24% of clients who did so, the rate of new infections and use of post-exposure prophylaxis (PEP) were low.

However, a French study found that community sexual health counsellors often encountered confusion about the on-demand schedule and suggested a unified message about when to start and stop PrEP. Such an approach could be especially relevant as people change their sexual behaviour and PrEP use in the wake of the COVID-19 crisis.

Daily tenofovir disoproxil fumarate/emtricitabine (Truvada) is approved for use as PrEP in many countries. In the UK and other countries where national health systems have been slow to provide or cover the cost of PrEP, many people use generic versions of the two drugs.

On-demand PrEP is also known as event-based PrEP or PrEP 2-1-1. It involves taking two tablets 2 to 24 hours before engaging in sex, taking a single tablet 24 hours after the first two, and another tablet 24 hours after that.

On-demand PrEP using daily Truvada was shown to be highly effective for gay and bisexual men in the French IPERGAY study. A newer pill, tenofovir alafenamide/emtricitabine (Descovy), is approved for daily PrEP in the US, but it has not yet been evaluated for event-based PrEP.

Starting and stopping PrEP

The French community-based organisation AIDES has offered support to new PrEP users since the early stages of the IPERGAY study. French guidelines endorse both daily and on-demand PrEP. Trained AIDES counsellors educate community members about HIV, STIs, PrEP adherence and harm reduction around recreational drug use. They are available to talk with new PrEP users during the first six months after starting PrEP and after each medical appointment.

The community health workers found that they received the most questions about how to start and stop PrEP, what to do if a dose is missed or not taken on time, and how to adjust their PrEP in accordance with their evolving sex lives. These questions suggest that guidelines and educational materials are not clear and are not adapted to the evolving needs of PrEP users, particularly at times in their lives when they need to switch regimens, according to the study authors. Read more via AIDSmap

Broussard J et al. PrEP 2-1-1 education increases PrEP uptake and preserves effective PrEP coverage in a large nurse-led community-based sexual health clinic in San Francisco. 23rd International AIDS Conference, abstract OAC0503, 2020.

Morel S et al. Overcoming the dichotomy of daily and event driven PrEP regimens for MSM: Lessons learned from community support programs in France. 23rd International AIDS Conference, abstract PED0759, 2020