Having antiretroviral medications on hand to take as post-exposure prophylaxis after potential exposure to HIV—an approach dubbed PEP-in-pocket, or PIP—is a feasible prevention option, especially for people who have sex infrequently, according to a presentation at IDWeek 2023.

“I really think PIP is a strong additional tool for patients and providers and gives more options—and a more granular approach—for HIV prevention,” presenter Isaac Bogoch, MD, of the University of Toronto, told POZ.

Pre-exposure prophylaxis (PrEP) pills taken every day or injections administered every other month are highly effective for HIV prevention. Taking PrEP pills “on demand” before and after sex (known as PrEP 2-1-1) can also be an effective option, especially for people who can anticipate when they are likely to have sex.

A buffet of HIV prevention approachesFrom Bogoch et al, IDWeek 2023

Another effective prevention method is post-exposure prophylaxis (PEP), which involves taking a month-long course of antiretrovirals after sex or other types of exposure. PEP is typically provided on an emergency basis after the fact, but PEP-in-pocket can be a good alternative under certain circumstances—for example, if a condom breaks, if a person has unanticipated condomless sex only a few times a year, if a person infrequently shares equipment to inject drugs or if a sex worker is at risk for sexual assault by a client.

Bogoch and his team evaluated the PEP-in-pocket approach at two HIV clinics in Toronto. After counseling, individuals who have infrequent (zero to four times per year) but high-risk exposures of any type were prescribed a course of antiretrovirals to have on hand if needed.  

PEP should be started as soon as possible after sex and definitely within 72 hours. This can be difficult, as potential exposures may occur at times and places when it’s not easy or convenient to access the medications, such as over a weekend or while traveling. Accessing PEP on an emergency basis may be particularly challenging for people who live in rural areas or lack transportation to a medical facility.

Although two drugs used as PrEP can prevent HIV from taking hold in the body, PEP—which is essentially very early treatment—requires a stronger three-drug regimen. Recommended PEP regimens include tenofovir disoproxil fumarate/emtricitabine (TDF/FTC, or Truvada) plus dolutegravir (Tivicay); tenofovir alafenamide/emtricitabine (TAF/FTC, or Descovy) plus dolutegravir; and Biktarvy (bictegravir/TAF/emtricitabine), all taken for 28 days.

The researchers published a brief report on PIP for people with low-frequency but high-risk HIV exposures in 2018, published a longer follow-up analysis in AIDS in 2020 and provided updates at the 2021 European AIDS Conference, this year’s Conference on Retroviruses and Opportunistic Infections and last week at IDWeek.

The latest retrospective analysis included 112 people who were prescribed PIP between February 2016 and December 2022. They had regular follow-up visits every four to six weeks. Almost all (96%) were assigned male at birth, most were gay or bisexual and the average age was 37 years. They used PIP for an average of 1.6 years.

During follow-up, 35 people (31%) self-initiated antiretrovirals following sexual exposure, including 19 who did so more than once, for a total of 69 courses of PIP. The drugs were discontinued early in five cases, four after a risk assessment by providers and once due to side effects.

Participants “fluidly transitioned” between different HIV prevention methods as circumstances warranted, with nearly a third switching from PIP to PrEP and a similar proportion switching from PrEP to PIP. There were 22 cases of bacterial sexually transmitted infections among 13 people, suggesting that some of them might also be candidates for doxycycline post-exposure prophylaxis (doxyPEP). No new cases of HIV were detected.

“PIP is an innovative HIV prevention strategy for individuals with a lower frequency of higher-risk HIV exposures and provides patients with autonomy and agency over their care,” the researchers concluded. “Patients may transition between PIP and PrEP based on evolving risk. PIP should be included with PEP and PrEP as a biomedical HIV prevention option for individuals at risk for infection.”

The benefits of short-term PIP compared with ongoing PrEP include less total time on antiretrovirals, potentially reducing side effects and lowering cost. A cost analysis comparing PIP, daily PrEP and on-demand PrEP is currently underway. Initial results (based on medication and clinic costs in Canada) suggest that PIP is about 40% less expensive, Bogoch reported. However, the three-drug regimen used for PIP could potentially cause more side effects for a short period compared with continuous use of two drugs for PrEP.

“PrEP (injectable, daily and on demand) and PEP are fantastic, but still leave significant gaps in care. PIP fills that gap nicely and enables people with a low frequency of high-risk (and occasionally unanticipated) exposures to have agency and autonomy over their HIV prevention care,” Bogoch told POZ. “Not everyone wants to wait for four hours in a busy emergency department at 2 a.m. to talk to a total stranger about the condomless sex they just had, or the rape they just survived, or the needle they stuck in their arm. We treat adults like adults and give them the full course of PEP ahead of time. It works, and people are happy.”

“Nothing is set in stone, and we routinely follow up with patients to reassess their HIV prevention needs,” he continued. “People do not take a linear path through life, and HIV risk is dynamic. We work with patients to adapt their HIV prevention modality to best suit their current and future needs. This is a patient-centered and evidence-based approach.”

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