SUMMARY:

Currently, there are two approved daily oral antiretroviral preexposure prophylaxis (PrEP) medications. The CDC has published guidelines on the use of PrEP – a powerful pharmacologic approach to reduce HIV risk in those at high risk. PrEP should be offered to adults and adolescents who weigh at least 35 kg (77 lb) and meet ‘at risk’ criteria (see below).

USPSTF Guidance (June 2019)

The USPSTF recommends offering PrEP to persons at high risk of HIV acquisition. This recommendation is Grade A, which means that PrEP should be offered or provided in the appropriate clinical settings (see below). In addition, the USPSTF document states that while associated with “small harms” (e.g., kidney and GI events), overall

The USPSTF found convincing evidence that PrEP is of substantial benefit for decreasing the risk of HIV infection in persons at high risk of HIV infection, either via sexual acquisition or through injection drug use. The USPSTF also found convincing evidence that adherence to PrEP is highly correlated with its efficacy in preventing the acquisition of HIV infection.

What is PrEP

• Emtricitabine (F) 200 mg and tenofovir disoproxil fumarate (TDF) 300 mg (F/TDF) tablet taken daily
• Emtricitabine (F) 200 mg tenofovir alafenamide  (TAF) 25 mg tablet (F/TAF) taken daily
  • F/TDF is recommended to prevent HIV infection among all persons at risk through sex or injection drug use
  • F/TAF is recommended to prevent HIV infection among persons at risk through sex, excluding people at risk through receptive vaginal sex because due to lack of studies for this indication
• Offer to those who are HIV-negative and at substantial risk for HIV
• Effectiveness estimates
  • Sexual transmission route: approximately 99% effective
  • Injection drug use: 74 to 84% effective (based on tenofovir alone and may be higher with combination pill)
  • Effectiveness strongly related to adherence to PrEP

Clinical Actions

• Clinical eligibility
  • Receive HIV testing to confirm negative status before starting PrEP
  • No signs/symptoms of acute HIV infection
  • Normal renal function
  • No contraindication to medications
  • Documented hepatitis B virus infection and vaccination status | Hepatitis B is not a contraindication but discontinuation of emtricitabine and tenofovir can result in rebound hepatitis and therefore patient must be monitored careful if PrEP is stopped
  • Document pregnancy intention
  • Screen/treat STDs
• Recommend regular monitoring of HIV infection status, side effects, adherence, and sexual or injection risk behaviors
• Reinforce the importance of adherence and HIV risk reduction, including encouraging condom use for additional protection
• Patients on PrEP should return to their health care provider every 3 months for a repeat HIV test and
  • Write a prescription refill if appropriate
  • Offer counseling about medication adherence and risk reduction
  • Test for STDs
  • Test for pregnancy
  • Assess side effects, if necessary
• At 3 months and every 6 months after, assess renal function using Cockcroft-Gault formula
  • F/TDF: Approved for use in persons with a eCrCl >60 ml/min
  • F/TAF: Approved for use in persons with eCrCl ≥30 ml/min
• Every 6 months test for bacterial STDs
• Stop PrEP if
  • Patient requests to stop
    • Counsel regarding other preventative measures
  • Patient now HIV positive (manage and refer)

Dosage Regimen

• Daily, continuing, oral doses of TDF/FTC (Truvada), ≤90 day supply
• Side Effects in clinical trials
  • Early side effects: Upset stomach or loss of appetite that were mild and usually went away within the first month
  • Some people experienced mild headache
  • No serious side effects were seen in trials, however
    • The medication may impair renal function and therefore renal function studies are required on follow up
    • Liver function can be adversely affected and patients should report symptoms (e.g. tea colored urine, light colored stool etc.)

KEY POINTS:

Who Should be Offered PrEP?

• Sexually active gay and bisexual men without HIV
• Sexually active heterosexual men and women without HIV
• Sexually active transgender persons without HIV
• Persons without HIV who inject drugs
• Persons who have been prescribed non-occupational post-exposure prophylaxis (PEP) and report continued risk behavior, or who have used multiple courses of PEP

Definitions

• Sexually-Active Adults and Adolescents
  • Anal or vaginal sex in the past 6 months and
    • HIV-positive sexual partner (especially if partner has unknown or detectable viral load) or
    • Recent (past 6 months) bacterial STI or
    • History of inconsistent or no condom use with sexual partner(s)
• Persons Who Inject Drugs
  • HIV-positive injecting partner or
  • Shares drug preparation or injection equipment

• Note: The USPSTF states that “It is important to note that men who have sex with men and heterosexually active persons are not considered to be at high risk if they are in a mutually monogamous relationship with a partner who has recently tested negative for HIV”

HIV-discordant Couples and Pregnancy

• Conception and pregnancy
  • PrEP is one of several options to protect the partner who is HIV-negative (see related ‘ObG Topics, below) in a couple considering pregnancy
  • Data on use of the PrEP medication has not shown increased risk of birth defects nor risk to breastfeeding children

 Breastfeeding

• The CDC states that “F/TDF as PrEP is considered generally safe for pregnant and breastfeeding women”
• For F/TDF, the FDA label states

The developmental and health benefits of breastfeeding and the mother’s clinical need for TRUVADA for HIV-1 PrEP should be considered along with any potential adverse effects on the breastfed child from TRUVADA and the risk of HIV-1 acquisition due to nonadherence and subsequent mother to child transmission

Women should not breastfeed if acute HIV-1 infection is suspected because of the risk of HIV-1 transmission to the infant.

PrEP vs PEP

• PrEP is only for people who are at ongoing substantial risk of HIV infection
• For a single high-risk event of potential HIV exposure (e.g., unprotected sex, needle-sharing injection drug use, or sexual assault—use postexposure prophylaxis (PEP) option , or PEP within 72 hours of exposure (see ‘Learn More – Primary Sources’ below)

Learn More – Primary Sources:

CDC: Pre-Exposure Prophylaxis (PrEP)

NIH: Pre-Exposure Prophylaxis (PrEP)

Preexposure Prophylaxis for the Prevention of HIV Infection: US Preventive Services Task Force Recommendation Statement (JAMA) 

USPSTF: Prevention of Human Immunodeficiency Virus (HIV) Infection: Pre-Exposure Prophylaxis (USPSTF)

ACOG Committee Opinion 595: Preexposure Prophylaxis for the Prevention of Human Immunodeficiency Virus

CDC PEP Guidelines

Related ObG Topics:

Screening & Treatment of Gynecologic infections in the HIV-Positive Woman

Cervical Cytology and HPV Screening in the HIV Positive Woman

CDC Recommends Conception Strategies When an Uninfected Woman’s Male Partner is HIV Positive

Optimizing Contraception for the HIV-positive Woman

Does Amniocentesis or CVS Increase the risk of HIV Vertical Transmission?