Advertisement

Antiretroviral PrEP for Injection-Drug Users?

Summary and Comment |
June 17, 2013

Antiretroviral PrEP for Injection-Drug Users?

  1. Carlos del Rio, MDAU022

In a randomized, controlled trial involving injection-drug users in Thailand, tenofovir reduced the risk for HIV infection.

  1. Carlos del Rio, MDAU022

Antiretroviral pre-exposure prophylaxis (PrEP) is effective in preventing sexually acquired HIV infection among men who have sex with men as well as heterosexual men and women. Might it also help to prevent HIV infection among injection-drug users? To find out, investigators from the CDC and the Thailand Ministry of Health conducted a study involving HIV-uninfected injection-drug users recruited at drug-treatment clinics in Bangkok.

A total of 2413 individuals were randomized to oral tenofovir or placebo, either administered daily via directly observed therapy (DOT) or provided at monthly visits. The decision to use DOT was up to the participants, who could switch at monthly visits. Each month during follow-up (mean duration, 4 years), participants received HIV testing and risk-reduction and adherence counseling. Drug levels were also measured at some of the clinics, and at the time of the first positive HIV test in all individuals who seroconverted.

The median age of participants was 31; 80% were men, and 48% had ≤6 years of education. Twenty-two percent were enrolled in a methadone program. Baseline characteristics were similar between groups, except that sexual intercourse with casual partners and having sex with men during the 12 weeks preceding enrollment were more common in the placebo group.

HIV infection was confirmed in 50 participants — 17 in the tenofovir group and 33 in the placebo group — for an overall 48.9% reduction in HIV incidence with tenofovir in intent-to-treat analysis. Efficacy was higher — 73.5% — among individuals with detectable tenofovir levels in their plasma.

Comment

This study is the first to demonstrate the efficacy of tenofovir in preventing HIV infection among injection-drug users. Almost concomitantly, the CDC published interim guidance for pre-exposure prophylaxis in this population. Interestingly, the CDC recommended using tenofovir/FTC (not tenofovir alone, as studied in Thailand), arguing that tenofovir/FTC and not tenofovir alone is approved by the FDA for prophylaxis. The CDC also suggested that prevention services targeting injection and sexual risk behaviors be provided for injection-drug users.

I must emphasize that this study used directly observed therapy as one strategy, and that efficacy of antiretrovirals for prevention depends on adherence. Thus, any PrEP program should incorporate strong adherence counseling.

  • Disclosures for Carlos del Rio, MD at time of publication Consultant / Advisory board Gilead Sciences; Pfizer Grant / research support CDC; NIH Editorial boards AIDS Research and Human Retroviruses; Journal of AIDS Leadership positions in professional societies HIV Medicine Association (Board of Directors); Infectious Diseases Society of America (Board of Directors); International AIDS Society-USA (Board of Directors)

Citation(s):

Your Comment

(will not be published)

Filtered HTML

  • Allowed HTML tags: <a> <em> <strong> <cite> <blockquote> <code> <ul> <ol> <li> <dl> <dt> <dd>
  • Web page addresses and e-mail addresses turn into links automatically.
  • Lines and paragraphs break automatically.

Plain text

  • No HTML tags allowed.
  • Web page addresses and e-mail addresses turn into links automatically.
  • Lines and paragraphs break automatically.
Do you have any conflict of interest to disclose?
CAPTCHA
This question is for testing whether you are a human visitor and to prevent automated spam submissions.
Image CAPTCHA
Enter the characters shown in the image.

Vertical Tabs

* Required

Reader comments are intended to encourage lively discussion of clinical topics with your peers in the medical community. We ask that you keep your remarks to a reasonable length, and we reserve the right to withhold publication of remarks that do not meet this standard.

PRIVACY: We will not use your email address, submitted for a comment, for any other purpose nor sell, rent, or share your e-mail address with any third parties. Please see our Privacy Policy.

Advertisement
Advertisement
Advertisement