PrEP Safer, More Effective Than Many Physicians Realize

Naveed Saleh, MD, MS


December 14, 2017

At the height of the AIDS epidemic, it seemed almost unimaginable that within 3 decades there would not only be effective treatment for the disease but also effective prophylaxis. In July 2012, in combination with safer sexual practices, the US Food and Drug Administration approved emtricitabine 200 mg and tenofovir disoproxil fumarate 300 mg (Truvada®) as a once-daily pill for HIV pre-exposure prophylaxis (PrEP) in high-risk adults. (Truvada had been previously approved for the treatment of HIV in 2004.) Then, in 2014, the Centers for Disease Control and Prevention issued comprehensive clinical practice guidelines recommending PrEP as a safe and effective option for men who have sex with men (MSM), adult injection drug users, and heterosexual adults at high risk for HIV.[1] But despite PrEP being touted as a powerful HIV prevention tool, only 10% of those patients who would benefit from PrEP receive it.

At IDWeek 2017, the air was abuzz with ideas about PrEP: how to facilitate its adoption among physicians, how to surmount barriers to treatment, and how to send the proper message about this remarkable innovation. Two notable PrEP-focused sessions included the John F. Enders Lecture, titled, "Making HIV Prevention Go Viral," and a press conference on PrEP education. In the John F. Enders Lecture, Connie Celum, MD, MPH, an infectious disease specialist and professor of medicine at the University of Washington, was honored in part for her pioneering work in PrEP.

PrEP Efficacy

Despite years of public advocacy and outreach highlighting the efficacy of PrEP, many healthcare providers may be surprised to learn just how effective this prophylaxis is. "Not only does PrEP work, but it works really well. It's not 100%, but it's around 90% protective among those who have taken the drug.... We found with analysis of the trials that showed efficacy that PrEP was effective in those who had greatest risk: those who had [sexually transmitted infections (STIs)], partners with high viral loads, MSM, and [those who engage in] condomless anal sex with a positive partner or a partner with STIs. We learned that adherence was higher in those taking great risk," Dr Celum said.

Specifically, Dr Celum pointed to research demonstrating that the relative risk reduction for HIV protection in MSM is 86% compared with 31% for statins for heart attack prevention and 40% for blood pressure control for stroke prevention.

Dr Celum pointed out a whole host of other benefits among American PrEP users including the following:

  • Decreased anxiety

  • Increased communication

  • Increased disclosure

  • Increased trust

  • Increased self-efficacy

  • Increased sexual pleasure

  • Increased intimacy

Limited Adverse Effects

In addition to being highly effective for those with high adherence, PrEP is also safe and well-tolerated by patients. However, according to Dr Celum, usage of PrEP can result in the following:

  • Transient gastrointestinal symptoms

  • Nonprogressive decline in renal function

  • Small decline in bone mineral density

Of note, Dr Celum said that the "accumulated safety evidence suggests that, at least in some patients, we may be able to relax safety monitoring." Furthermore, decreases in bone mineral density aren't clinically relevant. Finally, PrEP doesn't affect reproductive health including contraception, pregnancy, lactation, and male fertility.

On a related note, many physicians worry about resistance, but resistance is very uncommon with PrEP. "We found that resistance was quite rare and was almost exclusively limited to those who had acute infection when they started PrEP," Dr Celum said. "When you put it in context ... [concerns about PrEP resistance] pale compared with the number of infections that were averted."

Barriers to PrEP Prescription

Outside of PrEP strongholds like New York City and San Francisco, numerous barriers impede the wider adoption of PrEP prescription and use. Some of these barriers have to do with PrEP candidates who have limited knowledge of the product and are unaware that it's safe, effective, and covered by Medicaid.

However, some barriers lie with prescribers themselves.

Although infectious disease specialists feel comfortable taking sexual histories and prescribing PrEP, most patients at high risk for HIV present in emergency departments (EDs) or primary care practices. In these settings, an infectious disease specialist isn't readily available. Consequently, for more PrEP candidates to receive this treatment, ED physicians and primary care physicians have to feel comfortable with PrEP, which is often not the case.

"We need to get more education out to providers seeing people who might benefit from PrEP so that they are comfortable offering PrEP or at least referring [their patients for PrEP]. More of us need to get comfortable asking about sexual practices, figuring out who is at risk, and intervening to prevent HIV," said Rajesh T. Gandhi, MD, a professor of medicine at Harvard Medical School and director of HIV Clinical Services and Education at Massachusetts General Hospital, who moderated the press conference on PrEP education at IDWeek 2017.

In part, barriers to PrEP prescription or PrEP referral among providers are rooted in misconceptions and limited understanding of PrEP. In a study presented at the PrEP education press conference titled, "Emergency Medicine Physicians Overlooked in PrEP Education Efforts," Tortelli and coauthors found that in a survey of 67 emergency medicine physicians, although the majority of respondents were aware of PrEP, only 24% were knowledgeable about its guidelines.[2] Furthermore, 57% of ED physicians sampled were uncomfortable discussing PrEP with patients, 54% had concerns about whether PrEP was effective, 90% were concerned about adverse effects of PrEP, and 70% feared it would promote HIV resistance.

In addition, according to Tortelli and colleagues, emergency medicine physicians are unlikely to prescribe PrEP because it requires follow-up and continued care. Nevertheless, ED physicians can serve a crucial role in identifying patients at high risk for HIV—who would otherwise go unnoticed—and referring these patient to appropriate care.


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