The Pros and Cons of PrEP in the Real World

SAN ANSELMO, CA - NOVEMBER 23: Bottles of antiretroviral drug Truvada are displayed at Jack's Pharmacy on November 23, 2010 in San Anselmo, California. A study published by the New England Journal of Medicine showed that men who took the daily antiretroviral pill Truvada significantly reduced their risk of contracting HIV. (Photo Illustration by Justin Sullivan/Getty Images). Justin Sullivan/Getty Images News/Getty Images

Pre-exposure prophylaxis (PrEP) against HIV, providing HIV medication to uninfected people in order to reduce their likelihood of getting HIV, has always been controversial. There are several concerns about this practice. These range from worries about the potential for the development of drug-resistant virus if individuals are infected while using PrEP inconsistently... to social and economic justice concerns about diverting HIV medicines from infected people who need them to uninfected people as a form of prevention...

to fears about people choosing to engage in riskier behaviors because they know they are protected against HIV. These concerns are, of course, balanced against the potentially huge financial and medical benefits of PrEP effectively reducing the incidence of HIV among high-risk individuals.

The concerns are real. Drug-resistant HIV can develop when people are using PrEP ineffectively, although it seems to be relatively uncommon. HIV drugs are expensive and there will always be people who need them and can not afford them. And, as has clearly been shown in a 2015 paper looking at real-world use of PrEP in a clinical practice, many people using PrEP do decrease their use of condoms... and have very high rates of of non-HIV STDs.

The study looked at the sexual behavior, and STD rates, in over 600 men who have sex with men who chose to begin using PrEP, after either having it recommended to them by their doctors or asking for it themselves.

These men, on average, had more sex partners than men who chose not to start using PrEP after attending an intake visit. They were also more likely to have used PrEP in the past -- either as part of a research study or from another clinic.

The study found that more than 30 percent of men in the study were diagnosed with at least one non-HIV STD (primarily gonorrhea, chlamydia, or syphilis) within six months of starting to use PrEP.

Furthermore, of the subset of men who were surveyed about condom use, more than 40 percent had started using them less frequently. On the other hand, in the almost 400 person years of PrEP use, there were no transmissions of HIV.

In short, in the real world, PrEP is something of a mixed bag. While it's an effective way to drastically reduce HIV risk in otherwise high-risk populations, and may have positive effects on community health, that efficacy comes with some trade offs. A significant fraction of people using PrEP may start engaging in riskier sexual behaviors than they would have without being on PrEP. A significant fraction will be diagnosed with other STDs - including hepatitis C (HCV).

Is it a worthwhile trade off? For a lot of people, it probably is. However, it's a decision that should be made with discussion and education. In particular, people need to be reminded that HIV isn't the only STD out there. Then they can decide how they want to manage their risk.


Lehman DA, Baeten JM, McCoy CO, Weis JF, Peterson D, Mbara G, Donnell D, Thomas KK, Hendrix CW, Marzinke MA, Frenkel L, Ndase P, Mugo NR, Celum C, Overbaugh J, Matsen FA; Partners PrEP Study Team. Risk of drug resistance among persons acquiring HIV within a randomized clinical trial of single- or du 10.1093/infdis/jiu677.

Volk JE, Marcus JL, Phengrasamy T, Blechinger D, Nguyen DP, Follansbee S, Hare CB. No New HIV Infections with Increasing Use of HIV Preexposure Prophylaxis in a Clinical Practice Setting. Clin Infect Dis. 2015 Sep 1. pii: civ778. [Epub ahead of print - Accessed 9/20/15]

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