Can a Pill a Day Keep HIV Away?
In Combo With Safer Sex, Truvada Protects Gay/Bi Men From HIV Infection, Study Shows
PrEP Praise Comes With PrEP Warnings
Unfortunately, it takes more than a daily pill to prevent HIV infection. All of the experts who praised the iPrEx study were quick to warn that it's only one piece in the puzzle.
While the study showed that Truvada can protect gay and bisexual men, it can't be assumed that the same will hold true for heterosexual men and women, for couples in which only one member has HIV, or for intravenous drug users. Studies are under way to evaluate various PrEP formulations in these groups.
Truvada has not been approved by the FDA for prevention of HIV infection.
Fenton notes that PrEP cannot protect against STDs such as syphilis or chlamydia.
"It cannot be seen as the first line of defense against HIV," Fenton warns. "PrEP requires careful adherence, and is an intensive approach that won't be right for everyone. … Taking a daily pill is not as simple as it sounds."
In an editorial accompanying the Grant report in the Nov. 23 online edition of the New England Journal of Medicine, Walter Reed Army Institute researcher Nelson L. Michael, MD, PhD, notes the iPrEx study revealed several problems with PrEP:
- Men recently infected with HIV (and thus negative on a standard HIV test) developed drug-resistant HIV infections after starting PrEP.
- A small number of men showed signs of kidney dysfunction, a known side effect of Truvada. This means people taking the drug will have to be closely monitored.
- If so many men failed to take their Truvada every day during the strict confines of a clinical trial, what will happen in the real world?
- What will be the long-term safety of PrEP in people with health issues such as diabetes or high blood pressure?
- Will people taking PrEP forgo condom use, HIV testing, or other measures known to reduce HIV risk?
So what's the next step?
"A variety of expert and community advisory groups at the federal, state, and local levels are looking closely at the study data and will move forward in a deliberative and measured way over the coming months to determine whether and how these findings should be incorporated into ongoing HIV prevention programs," Department of Health and Human Services Assistant Secretary Howard K. Koh, MD, says in a news release.
Meanwhile, the CDC cautions gay and bisexual men and transgendered women that they should still:
- Use condoms consistently and correctly
- Get tested to know their status and that of their partner(s) for certain
- Get tested -- and treated if needed -- for other sexually transmitted infections that can facilitate HIV transmission, such as syphilis and gonorrhea
- Get information and support to reduce drug use and sexual risk behavior
- Reduce their number of sexual partners