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HIV Pre-Exposure Prophylaxis (PrEP) – Who it’s for? image

HIV Pre-Exposure Prophylaxis (PrEP) – Who it’s for?

Review the latest recommendations with

David Malebranche, MD, MPH and Ariel Watriss, MSN, NP-C

Dr. Malebranche (he/him/his), an internal medicine specialist with expertise in sexual health and HIV/STI prevention and treatment, is a clinician at the AIDS Healthcare Foundation Health Care Center in midtown Atlanta

Ariel Watriss (she/her/hers) is a college health nurse practitioner at Tufts University in Boston, and a renowned sexual health clinician and educator


There are two types of PrEP approved by the Food and Drug Administration (FDA) currently available – Truvada and Descovy. Both work by stopping the HIV replication process. While HIV PrEP is recommended for all individuals that it is applicable for, at this time, only Truvada is approved for cis women who have vaginal sex.

  • Truvada brand name (Emtricitabine (F) 200mg with tenofovir disoproxil fumarate (TDF) 300mg) daily
  • Descovy brand name (Emtricitabine (F) 200mg with tenofovir alafenamide (TAF) 25mg) daily

Of note, we refer to Truvada as F/TDF and Descovy as F/TAF throughout


Providing Pre-exposure Prophylaxis

  • Goal of PrEP is to reduce the acquisition of HIV and its subsequent costs to individuals and society
  • PrEP has been a part of the HIV prevention landscape since 2012
  • Both HIV PrEP oral tablets contain two antiretroviral medications called nucleoside reverse transcriptase inhibitors (NRTIs)
    • These medications work by inhibiting the enzyme reverse transcriptase that HIV needs to replicate.
    • Both tablets are used in many common HIV treatment regimens

Oral PrEP medications

FDA Approved Regimens:

  • Truvada | Emtricitabine (F) 200mg and tenofovir disoproxil (TDF) 300mg) | one tablet orally daily, with or without food
  • Descovy | Emtricitabine (F) 200mg and tenofovir alafenamid (TAF) 25mg) | one tablet orally daily, with or without food

What many clinicians wonder next is “What patients would be good candidates for PrEP?” PrEP is a sexual health option for people interested in HIV prevention and could be appropriate for many patients you see on a daily basis.

Who It’s For – CDC Guidance and Other Considerations

The CDC describes patients falling into categories of “risk groups” with regards to which of your patients would be good candidates for PrEP. However, we caution the idea of patients as levels of “risk,” particularly when it comes to sexual health. What it involves is taking a good sexual history and documenting what behavioral choices they make, then offering PrEP as an option for HIV prevention.

PrEP is for people without HIV who could be exposed to HIV from sex or injection drug use.

CDC recommends the following patients should be assessed for PrEP including:

  • 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 behaviors that could expose them to HIV, or who have used multiple courses of PEP

For 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 bacterial STI; or
  • History of inconsistent or no condom use with sexual partner(s)

For Persons who inject drugs:

  • HIV-positive injecting partner; or
  • Shares drug preparation or injection equipment

All persons eligible for PrEP:

  • Documented negative HIV test result before prescribing PrEP; and
  • No signs/symptoms of acute HIV infection; and
  • Normal renal function; and
  • No contraindicated medications

NOTE: While the CDC compartmentalizes “risk groups” as listed above, as clinicians we must remember that sexual health does not fit neatly into static compartments. Sexuality and sexual behavior are fluid, and individuals may change their partners, behavior, and condom use over time and depending on the situation.

The CDC guidance is exactly what it is – guidance. Nothing replaces taking a good sexual history to discover which patients may be good candidates for PrEP.

  • Individuals who do not fit in the categories mentioned above could still benefit from PrEP – so be sure not to limit offering PrEP to just certain groups of people
  • Anyone who is sexually active could be a candidate for PrEP.
  • Patients who ask for PrEP may not feel comfortable sharing all their sexual behavior with medical providers due to fear of judgment and stigma
  • If a patient comes into your office inquiring about PrEP, even if they don’t verbally describe specific behaviors that the CDC defines as “risky,” they are asking for a reason

Dosage Regimen

These medications are approved to prevent HIV infection in adults and adolescents weighing at least 35 kg (77 lb) as follows:

  • Daily oral PrEP with F/TDF (Truvada) is recommended to prevent HIV infection among all persons at risk through sex or injection drug use.
  • Daily oral PrEP with F/TAF (Descovy) is recommended to prevent HIV infection among persons at risk through sex, excluding people at risk through receptive vaginal sex. F/TAF has not yet been studied for HIV prevention for receptive vaginal sex.

Selecting a Regimen

  • Determination of which oral regimen is appropriate depends on a patient’s clinical status, comorbidities, as well as potential side effects and medication interactions
    • Both F/TDF and F/TAF are equally effective in reducing HIV transmission 
    • F/TDF (Descovy) is the only FDA-approved PrEP option for cis women who have vaginal sex | May be better for people with a history of hypercholesterolemia 
    • F/TAF (Truvada) is FDA-approved for use by transgender women, transgender men, and men who have sex with men | the best option for persons with osteoporosis and chronic kidney disease with a CrCl as low as 30 ml/min 
  • Comorbidities 
    • Hepatitis B 
    • HIV 
    • Renal disease 
  • Common side effects 
    • Mild to moderate gastritis at start of med course- usually tapers within 3 to 4 weeks | Can sometimes include diarrhea
    • Headaches 
  • Medication interaction 
    • Other drugs that could affect renal function may require closer renal function while PrEP is being used
    • Other antiviral medications can impact PrEP response and need to be reviewed with clinical use on a case by case basis

On-demand” PrEP

“On-demand” PrEP is not currently FDA-approved for use in the United States

  • Would be an option for people who may not engage in sex regularly or plan sexual encounters 
  • Involves the following regimen schedule for TDF/FTC only
    • Take two tablets at least 2 hours and not more than 24 hours before sex
    • Take one tablet 24 hours after first 2 pills taken
    • Take one tablet 48 hours after first 2 pills taken

PrEP safety and efficacy

PrEP, when used as indicated, has been determined to be safe and effective in the prevention of HIV transmission among diverse populations, including

  • Men who have sex with men and transgender women: 85 – 100% risk reduction 
  • Heterosexual women and men: 63 – 90% risk reduction 
  • Persons who Inject Drugs (PWID) regardless of sexual activity: 73.5% risk reduction 
  • Adolescents who weigh over 35kg: >95% risk reduction

Clinical considerations with initiation

  • Consider sexual health needs beyond HIV prevention- PrEP only offers prevention for HIV, not other STIs
  • These medications must be monitored closely for patients with chronic active Hepatitis B (persistent positive Hepatitis B Surface Antigen)
  • These medications require healthy kidney function (eCrCl >60 ml/min for TDF/FTC and eCrCl >30 ml/min for TAF/FTC)
  • Can be prescribed by primary care providers without requiring infectious disease specialist or consult prior to initiation [for more information see Initial Visit, Dosing, and Follow Up or Implement and Maintain a Prep Clinic in the Resource Center

Learn More – Primary Sources:

CDC Pre-Exposure Prophylaxis for HIV Prevention

PrEP and Adolescents: The Role of Providers in Ending the AIDS Epidemic (Hosek et al. Pediatrics, 2020) 

Emtricitabine-tenofovir concentrations and pre-exposure prophylaxis efficacy in men who have sex with men (Anderson et al. Sci Transl Med, 2012) 

Antiretroviral prophylaxis for HIV prevention in heterosexual men and women (Baeten et al, N Engl J Med, 2012) 

Bangkok Tenofovir Study Group. 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 (Choopanya et al. Lancet, 2013) 

Emtricitabine and tenofovir alafenamide vs emtricitabine and tenofovir disoproxil fumarate for HIV pre-exposure prophylaxis (DISCOVER): primary results from a randomised, double-blind, multicentre, active-controlled, phase 3, non-inferiority trial (Mayer et al, The Lancet 2020) 

Commercial Support

This educational activity is supported by an independent educational grant from Gilead Sciences

Faculty Disclosures

David Malebranche, MD, MPH serves on the PrEP speakers bureau for Gilead Sciences, Inc 

Ariel Watriss, MSN, NP-C has no relevant financial relationships to disclose