Pre-exposure prophylaxis (PrEP)

CME credit available from Harvard Medical School through March 2020.

Published Materials

The goal of this activity is to educate prescribers about the safety and efficacy of pre-exposure prophylaxis (PrEP) with tenofovir plus emtricitabine for reducing the risk of acquiring human immunodeficiency virus (HIV). Along with the latest data on HIV epidemiology, recommendations are made for implementing an ongoing prevention program, including identifying patients who can benefit from PrEP and a schedule for follow-up assessments.

In 2015, about 40,000 people became infected with HIV,1 but pre-exposure prophylaxis can reduce this number. FDA approved in 2012, tenofovir 300 mg-emtricitabine 200 mg, brand name Truvada, is a once daily medication to prevent HIV infection. Clinical trials in men who have sex with men (MSM), heterosexual men and women, and injection drug users resulted in significant reductions in HIV infection rates in people with a high HIV risk. 3 4 5

PrEP significantly decreased the risk of HIV infection in randomized patients. 3 4

Patients who comply with PrEP and take it every day dropped the risk of HIV by at least 90%.

Tenofovir-emtricitabine is relatively safe. Patients taking PrEP may have nausea and dizziness, but these should resolve over the first few weeks of treatment. Bone mineral density and renal function may decrease in some patients, but both improve after stopping the medications.

A significant concern about PrEP was the risk of developing HIV viruses that are resistant to tenofovir-emtricitabine. However, during clinical trials no cases of resistant HIV occurred.6 A real world assessment of PrEP also found no resistant HIV infections, or any HIV infections.7 One case report of a compliant PrEP patient who became infected with HIV found the patient had been infected with an HIV virus that was resistant to tenofovir-emtricitabine.8 To date, no cases of resistant HIV strains due to PrEP have been reported.

Between 2012 and 2015 PrEP prescribing increased 4-fold to include 50,000 patients.9 However, an estimated 1.2 million people are considered at high risk for acquiring HIV.10

Many more patients need PrEP than are currently taking PrEP

Opportunities for expansion of PrEP services to at risk people is needed. Primary care providers are uniquely positioned to provide the follow-up and longitudinal relationships needed for PrEP recommendation and services.

PrEP Prescribing is Straightforward

Five steps to prescribing PrEP make the process simple.

  1. Assess HIV risk
  2. Check labs
  3. Ensure patient access to medication
  4. Prescribe PrEP
  5. Follow up

In conjunction with other risk reduction changes, such as using barrier methods (e.g., condoms) for sexual contact and clean needle exchanges for injection drug users, PrEP provides another opportunity for HIV prevention.

For detailed information on each of the steps for PrEP, see the summary document above.

Additional Resources for Providers
Additional Resources for Patients

Information current at time of publication, March 2017.

The content of this website is educational in nature and includes general recommendations only; specific clinical decisions should only be made by a treating physician based on the individual patient’s clinical condition.

  1. Centers for Disease Control and Prevention. Diagnoses of HIV Infection in the United States and Dependent Areas, 2015. 2016; Accessed January 21 2017.
  2. Centers for Disease Control and Prevention. HIV in the United States: At a Glance. 2016;  Accessed January 18 2017.
  3. Grant RM, Lama JR, Anderson PL, et al. Preexposure chemoprophylaxis for HIV prevention in men who have sex with men. N Engl J Med. 2010;363(27):2587-2599.
  4. Baeten JM, Donnell D, Ndase P, et al. Antiretroviral prophylaxis for HIV prevention in heterosexual men and women. N Engl J Med. 2012;367(5):399-410.
  5. Choopanya K, Martin M, Suntharasamai P, et al. Antiretroviral prophylaxis for HIV infection in injecting drug users in Bangkok, Thailand (the Bangkok Tenofovir Study): a randomised, double-blind, placebo-controlled phase 3 trial. Lancet. 2013;381(9883):2083-2090.
  6. Centers for Disease Control and Prevention. Preexposure prophylaxis for the prevention of HIV infection in the United States Centers for Disease Control; May 2014.
  7. Volk JE, Marcus JL, Phengrasamy T, et al. No New HIV Infections With Increasing Use of HIV Preexposure Prophylaxis in a Clinical Practice Setting. Clin Infect Dis. 2015;61(10):1601-1603.
  8. Knox DC et al. HIV-1 infection with multiclass resistance despite PrEP. Conference on Retroviruses and Opportunistic Infections (Boston). 2016;abstract number: 169aLB.
  9. Bush S et al. ASM/ICAAC 2016; Boston MA. #2651. Accessed January 17 2017.
  10. Smith DK, Van Handel M, Wolitski RJ, et al. Vital Signs: Estimated Percentages and Numbers of Adults with Indications for Preexposure Prophylaxis to Prevent HIV Acquisition–United States, 2015. MMWR Morb Mortal Wkly Rep. 2015;64(46):1291-1295.