CDC Addresses HIV Preexposure Prophylaxis in Heterosexuals

Laurie Barclay, MD

August 13, 2012

August 13, 2012 — The US Centers for Disease Control and Prevention (CDC) has offered interim guidelines regarding the use of preexposure prophylaxis (PrEP) to prevent human immunodeficiency virus (HIV) infection among heterosexually active adults. The new recommendations appear in the August 10 issue of the Morbidity and Mortality Weekly Report.

"In the United States, an estimated 48,100 new [HIV] infections occurred in 2009," write D.K. Smith, MD, from the National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, CDC, and colleagues. "Of these, 27% were in heterosexual men and women who did not inject drugs, and 64% were in men who have sex with men (MSM), including 3% in MSM who inject drugs."

The CDC issued interim guidance in January 2011 regarding antiretroviral PrEP to reduce the risk for HIV acquisition among MSM, based on safety and efficacy trials of daily oral tenofovir disoproxil fumarate 300 mg (TDF)/emtricitabine 200 mg (FTC). These recommendations still apply to MSM, including those who also have sex with women.

On July 16, the US Food and Drug Administration (FDA) approved a label indication for HIV PrEP among heterosexuals and MSM based on findings of trials conducted since January 2011 among heterosexual men and women. The current CDC interim recommendations summarize the new evidence and address pregnancy and safety considerations for heterosexually active adults at very high risk for sexual HIV acquisition, such as those with partners known to have HIV infection.

Medical epidemiologists in the Division of HIV/AIDS Prevention of the National Center for HIV, Viral Hepatitis, STD, and TB Prevention at the CDC reviewed the findings of 4 randomized, double-blind, placebo-controlled, clinical trials of oral PrEP with TDF and FTC in HIV-uninfected, heterosexually active adults. Experts from other federal health agencies, academic institutions, the health department, and community also offered their input.

Two studies showed that consistent, daily oral TDF/FTC use safely lowered the risk for sexual HIV acquisition by heterosexual women and men. However, a third study showed that PrEP was ineffective in heterosexual women, but medication adherence was low in this trial. Results from a fourth study are pending; results are due late in 2013.

Highlights of CDC Recommendations

  • PrEP for heterosexually active adults should be targeted to persons at very high risk for HIV infection, particularly uninfected persons whose regular sexual partners are documented to be positive for HIV infection. For persons with unknown or positive HIV status, TDF/FTC is contraindicated for PrEP.

  • Daily doses of TDF/FTC can safely and effectively lower the risk for HIV infection in women and men who are at very high risk of acquiring HIV from penile–vaginal sex.

  • To help protect the HIV-negative partner in discordant couples who are attempting to conceive, PrEP use may be one of several options.

  • Before starting PrEP, a woman of childbearing potential should be tested for pregnancy and the results documented. If this test is negative, it should be repeated regularly while she is undergoing PrEP.

  • To facilitate informed decision making, clinicians should counsel women who are pregnant before starting PrEP or who become pregnant while undergoing PrEP regarding potential risks and benefits of continuing PrEP. Clinicians should prospectively and anonymously submit information about a pregnancy occurring during PrEP to the Antiretroviral Use in Pregnancy Registry.

Counseling Patients and Ongoing Follow-Up

  • Clinicians should counsel their patients about the need for adherence to daily doses of medication to ensure efficacy of TDF/FTC for HIV prevention.

  • Clinicians should also advise their patients that long-term safety of TDF/FTC in HIV-uninfected adults or after fetal exposure is still unclear. Investigators have found no adverse effects of TDF/FTC exposure in utero and while nursing, but data are still incomplete for women in HIV-discordant couples using TDF/FTC for HIV PrEP.

  • Clinicians should report to the FDA's MedWatch any serious adverse events associated with use of TDF/FTC for PrEP.

  • PrEP is only one facet of a comprehensive prevention strategy, which should include risk-reduction, PrEP medication adherence counseling, and ensuring availability of condoms.

  • Patients receiving PrEP should have laboratory screening tests at least every 6 months and receive prompt treatment of any detected sexually transmitted infection.

  • At each quarterly follow-up visit, patients receiving PrEP should undergo monitoring of HIV status, pregnancy status, adverse effects, adherence, and risk behaviors.

"CDC and other [US Public Health Service (PHS)] agencies are developing PHS guidelines on the use of PrEP as part of a comprehensive set of HIV prevention services that will include specific recommendations for use with MSM and heterosexually active adults at very high risk for HIV acquisition," the authors write. "The guidelines will be updated as information about factors affecting efficacy and safety for all transmission risk groups becomes available from additional studies."

The authors have disclosed no relevant financial relationships.

Morb Mortal Wkly Rep. 2012;61:586-589. Full text


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