Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington, Seattle jstekler@uw.edu
Dr. Stewart reported no potential conflict of interest relevant to this article. Dr. Stekler sat on an advisory board of Gilead Sciences, Inc., manufacturer of the Food and Drug Administration-approved PrEP combination medication, and was investigator of record for the participation of the University of Washington AIDS Clinical Trial Unit in ACTU A5305/HPTN 069 (NEXT-PrEP), for which Gilead Sciences, Inc., and ViiV Healthcare provided study medications.
Infection with HIV in which viral mutations are associated with emtricitabine or tenofovir resistance is rare among the few people infected with HIV after starting PrEP.9 In RCTs, most drug resistance occurred among people who started PrEP when they were already HIV-positive (because they were screened with antibody-only HIV tests that did not detect recent infection).10
Other medications, routes of administration, and dosing schedules are being studied for safety and efficacy as PrEP for HIV infection.11,12
For whom should PrEP be prescribed? There are 2 ways to identify candidates for PrEP:
Passive prescribing relies on patients self-identifying as being at risk of HIV infection and asking about PrEP. Many at-risk patients do not recognize their need for PrEP, however.13
Active screening requires that physicians, or their staff, take a sexual history from all patients. However, reviewing detailed sexual histories with every patient in a busy practice can be overwhelming. One way to begin identifying patients for whom PrEP is appropriate is to commit to talking to subsets of potentially high-risk patients, such as MSM or transgender patients.6 Sexual orientation and gender identity are not direct risk factors; a nuanced sexual history is often needed to understand potential exposures. A diagnosis of syphilis or other bacterial STI is a marker of high risk of HIV acquisition.14
To help identify which of your patients might benefit from PrEP, the PrEP guidelines from the Centers for Disease Control and Prevention (CDC)15 and tools developed by other sources16,17 recommend several key screening questions about sexual behavior and substance abuse (TABLE 115-17).
Familiarity with PrEP and comfort taking a sexual history to screen for risk of HIV acquisition are essential first steps in prescribing PrEP under CDC guidelines.6,18 In primary care, female patients are routinely questioned to assess their need for contraception; similarly, screening questions to assess PrEP eligibility can be easily incorporated into practice.
