Last month, the Centers for Disease Control published guidelines for the use of Pre-exposure Prophylaxis (PrEP) in the prevention of HIV transmission. Since then, discussions about the safety and utility of PrEP have gone from theoretical debates in the research and public health community to the Facebook pages of potential patients with concrete concerns. To help get information out there, The San Diego LGBT Center will be hosting a Town Hall meeting on PrEP and Truvada Tuesday, June 24 at 6:30 p.m. Here are some of the basics.
What is PrEP?
PrEP stands for Pre-exposure Prophylaxis. It’s not a specific medication, but rather the idea that taking medications while HIV (-) might prevent you from contracting HIV. Evidence that PrEP might work has been building for some time, and having explicit CDC guidelines helps move it from something doctors “in-the-know” might suggest to something that every doctor should consider when treating patients at risk for contracting HIV.
The precursor to PrEP was Post-exposure Prophylaxis, or PEP, the practice of using medications to prevent someone from contracting HIV after a potential exposure. PEP was first used to treat medical professionals exposed to HIV at work, and later expanded to other potential exposures, such as rape.
PEP and PrEP are similar in that they are based on the idea that having HIV medications in the bloodstream near the time of exposure might kill the virus before it can get a foothold in the body. Ethically, however, they are considered very different. PEP was about finding a way to help people who had already been exposed. You could try almost anything safe that might help. PrEP involves telling people you can make an exposure less risky. That required more data on safety and effectiveness, which is why it took a little longer to get PrEP this far, and why the guidelines include who should be considered a candidate.
What is Truvada?
Truvada is a pill made by Gilead Sciences that combines two HIV medications: tenofavir (AKA Viread, TDF) and emtricitabine (AKA Emtriva, Coviracil, FTC). It was approved for use as PrEP by the FDA in 2012. It was the drug combination used in the iPrEx trial, one of the major sources of information for the CDC guidelines. Because it has arguably the best data and is approved, it is the drug most mentioned in PrEP conversations, but there is positive data for other medications. Don’t be surprised if patients who can’t take Truvada, or cost, drive future consideration of other anti-retrovirals as PrEP.
What are the pros and cons?
The pros are fairly clear. Taking the Truvada combo as PrEP works and it is well tolerated. The iPrEx trial showed that gay and bisexual men given PrEP were 44 percent less likely to contract HIV. That may not sound great, but note the word “given,” which doesn’t necessarily mean taking. For men whose blood work showed they were consistently taking the pill, the risk reduction was more like 90 percent. No safety concerns were noted, and side effects were largely limited to upset stomach or loss of appetite and usually stopped in a month.
The cons depend a bit more on your point of view. PrEP doesn’t prevent other sexually transmitted diseases (STD), like gonorrhea and syphilis. It’s not perfect. It wouldn’t treat an unknown STD, like HIV once was. It’s not a vaccine. It’s not cheap, though insurance companies are beginning to cover it, and the CDC guidelines should encourage more to do so.
Those points are often summed up in two arguments: condoms are better and there is a drug company conspiracy.
Condoms, when used, are effective in preventing the transmission of HIV and other STDs. Some opponents fear that men on PrEP will stop using condoms, effectively eliminating any risk reduction for HIV transmission, and increasing the risk of contracting other STDs.
The conspiracy argument is that drug companies are pushing PrEP as a way to maximize their profits at the expense of research into vaccines and cures. What could be better for their margin that turning all gay and bisexual men (and possibly some straight guys) into daily customers.
So is PrEP a good thing or not? (Opinion alert!)
I consider PrEP to be the most important advance in HIV prevention in years. Even if you believe it is inferior to condoms, having another weapon is a good thing, particularly with study after study showing that condom use is inconsistent.
The concern about other STDs is real, but that doesn’t mean PrEP shouldn’t be an option. There already exists a pill that, taken regularly, mitigates one of the major consequences of intercourse without preventing STDs. It’s called birth control, and we prescribe it all the time. While a full discussion of sexual health is warranted, doctors don’t refuse to prescribe the pill because condoms would stop pregnancy and STDs.
Neither do physicians typically make behavioral compliance a condition of prescribing effective medications. No doctor would withhold medications for hypertension and diabetes just because a patient hadn’t lost weight or started exercising. So why would we withhold PrEP even because someone might not use condoms?
As to the conspiracy theories, I don’t know what motivates the board of Gilead or any other pharmaceutical company, but most of the people I have met in the pharmaceutical industry are driven by a desire to help cure disease, not turn additional profit. Further, most of our effective vaccines boost the immune system to help everyone fight off a disease that most people handle just fine. The polio virus, for example, only causes paralysis in a handful of patients – most people have an upset stomach at worst. HIV attacks the immune system directly, and very few people can control the virus on their own. I’m all for continued vaccine research, but we may need some other options in the meantime.
So what do I do?
Be informed. Talk to your doctor. If he or she doesn’t know about PrEP, find one who does. Then make the decision that is best for you.
