Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
. 2016 Jan;11(1):49-55.
doi: 10.1097/COH.0000000000000209.

Should we fear resistance from tenofovir/emtricitabine preexposure prophylaxis?

Urvi M Parikh  1 , John W Mellors
Affiliations
Review

Should we fear resistance from tenofovir/emtricitabine preexposure prophylaxis?

Urvi M Parikh et al. Curr Opin HIV AIDS. 2016 Jan.

Abstract

Purpose of review: To review current data on HIV-1 resistance arising from the use of fixed dose combination tenofovir disoproxil fumarate/emtricitabine (TDF/FTC) for preexposure prophylaxis (PrEP) to prevent HIV-1 infection.

Recent findings: Resistance to tenofovir (TNV) or FTC is infrequently selected by TDF/FTC PrEP if started before HIV-1 infection has occurred, but is much more common when inadvertently started during undiagnosed acute infection. Mathematical modeling predicts that the number of HIV-1 infections averted by the use of PrEP far exceeds the increase in drug-resistant infections that could occur from PrEP. Studies in macaques show that TNV-resistant virus but not FTC-resistant virus can cause breakthrough infection despite TDF/FTC PrEP. FTC resistance with M184 V/I occurs more frequently than TFV resistance with K65R in seroconverters from clinical trials of TDF/FTC PrEP.

Summary: The benefit of preventing HIV-1 infections with TDF/FTC PrEP far outweighs the risk of drug-resistant infection, provided PrEP is not started in persons with undiagnosed HIV-1 infection. We should respect but not fear HIV-1 resistance from TDF/FTC PrEP and recognize that most TNV or FTC resistance will arise from its use for antiretroviral therapy (ART). Preventing ART failure or detecting it early is most important for preventing the spread of HIV-1 resistance to TDF/FTC and preserving its effectiveness for both PrEP and ART.

PubMed Disclaimer

Conflict of interest statement

Conflicts of interest

J.W.M. is a consultant to Gilead Sciences and holds share options in Co-Crystal, Inc. No other conflicts are reported. U.M.P reports no potential conflicts.

Figures

FIGURE 1
FIGURE 1
Global Threat of Resistance
See this image and copyright information in PMC

References

    1. WHO. HIV/AIDS Fact Sheet N360. 2015 Jul 20; http://www.who.int/mediacentre/factsheets/fs360/en/2015.
    1. UNAIDS. Global Report: UNAIDS Report on the Global AIDS epidemic 2013. 2013 http://www.unaids.org/sites/default/files/en/media/unaids/contentassets/....
    1. Roehr B. FDA approves first drug to prevent HIV infection. BMJ. 2012;345:e4879. - PubMed
    1. Plosker GL. Emtricitabine/tenofovir disoproxil fumarate: a review of its use in HIV-1 pre-exposure prophylaxis. Drugs. 2013;73(3):279–91. - PubMed
    1. WHO. Consolidated guidelines on the use of antiretroviral drugs for treating and preventing HIV infection. Recommendations for a public health approach. 2013 http://www.who.int/hiv/pub/guidelines/arv2013/en/ - PubMed

Publication types

MeSH terms