Learn About PrEP

Today, prescription medications provide an effective tool to prevent HIV. Patients at high risk for HIV may be able to take advantage of newer medicines prescribed by their healthcare providers for pre-exposure prophylaxis (PrEP) and post-exposure prophylaxis (PEP).

PrEP is the use of antiretroviral medication to prevent acquisition of HIV infection. PrEP is used by HIV uninfected people who are at high risk of being exposed to HIV through sexual contact or injection drug use. At present, the only medication with an FDA-approved indication for PrEP is oral tenofovir emtricitabine (TDF-FTC), which is available as a fixed-dose combination in a tablet called Truvada®. This medication is also commonly used in the treatment of HIV.


What are the guidelines for prescribing PrEP?

PrEP was classified as a grade A recommendationexternal icon by the U.S. Preventive Services Task Force in June of 2019, deeming it highly recommended for patients at high risk of HIV. Comprehensive guidelines for prescribing PrEP have been developed and are described in the Centers for Disease Control (CDC) Guidelines pdf icon[PDF – 2 MB], and the Clinical Providers’ Supplement pdf icon[PDF – 2 MB].

Who can prescribe PrEP?

Any licensed prescriber can prescribe TDF-FTC as PrEP. Specialization in infectious diseases or HIV medicine is not required. In fact, primary care providers who see members of populations at high risk of HIV on a routine basis should consider offering PrEP to all eligible patients.

To whom should I offer PrEP?

PrEP is for people without HIV that are at very high risk for acquiring infection from sex or injection drug use. People at high risk who should be assessed for PrEP include approximately:

  • 1 in 4 sexually active gay and bisexual adult men without HIV who:
    • Have an HIV-positive partner, or
    • Have multiple partners, a partner with multiple partners, or a partner whose HIV status is unknown and
    • Have anal sex without a condom, or
    • Recently had a sexually transmitted infection (e.g. syphilis).
  • 1 in 5 adults without HIV who inject drugs who:
    • Share needles or equipment to inject drugs, or
    • Recently went to a drug treatment program (specifically, a methadone, buprenorphine, or suboxone treatment program), or
    • Are at risk for getting HIV from sex.
  • 1 in 200 sexually active heterosexual adults without HIV who:
    • Have an HIV-positive partner, or
    • Have multiple partners, a partner with multiple partners, or a partner whose HIV status is unknown and
    • Do not always use a condom for sex with people who inject drugs, or
    • Are women who do not always use a condom for sex with bisexual men.

How is TDF-FTC for PrEP prescribed?

TDF-FTC for oral PrEP is taken once daily by mouth.

PrEP should be discontinued immediately if:

  • The patient becomes HIV-infected
  • The patient experiences toxicity or symptoms that cannot be managed
  • The patient becomes pregnant

How important is adherence to PrEP?

PrEP efficacy is highly dependent upon adherence.  According to a dedicated analysis of adherence from all trials to date, PrEP was non-effıcacious when adherence was low, but when moderate or high adherence was achieved, efficacy was modest or relatively high, respectively. Among the study subjects with detectable plasma tenofovir levels in iPrEx, Partners PrEP, TDF2, and BTS, efficacy ranged from 74 to 92%.

Is PrEP safe?

Yes, in prevention studies to date, TDF-FTC for PrEP has not caused serious short-term safety concerns. Among HIV-infected adults TDF-FTC has caused renal toxicity and decreased bone mineral density, when used by HIV-infected people for HIV treatment, and administered for months and years.

Who is not eligible for PrEP?

  1. HIV-positive people. Individuals must be confirmed as HIV-negative before initiating PrEP. Excluding those with acute HIV infection is critically important, as there is a risk of developing resistant HIV if they are inadvertently started on TDF-FTC as PrEP. (TDF-FTC is an appropriate component of a regimen to treat HIV, but must be combined with an additional agent from another class of antiretrovirals to provide effective treatment.)
  2. People with renal insufficiency. Providers should confirm that the patient’s calculated creatinine clearance is ≥60 mL/minute (Cockcroft-Gault formula) before initiating PrEP.

Additionally, those who indicate that they are not ready to adhere to daily oral TDF-FTC should not be prescribed PrEP (since efficacy is extremely limited when patients do not adhere, as described above).

What baseline assessment is required for individuals beginning PrEP?

The most important aspect of the baseline assessment is ascertaining that the patient is not already HIV-infected. HIV testing should be conducted immediately prior to starting PrEP, ideally on the same day the prescription is provided.

What additional support and ongoing assessment are required for patients on PrEP?

As mentioned above, PrEP should be prescribed as part of a combination prevention plan that includes regular HIV testing, discussions about adherence, safer sex behaviors, and condom use.

Will PrEP be covered by my patients’ health insurance?

Most insurance plans and state Medicaid programs are covering TDF-FTC as PrEP. Prior authorization may be required. Other payment assistance includes:

If I take care of both members of a serodiscordant couple, is it preferable to treat just the HIV-positive partner, just the HIV-negative partner, or both?

Experts recommend that all people with HIV be treated, regardless of clinical status or CD4 cell count. Virologic suppression of the HIV-infected partner protects his or her health and the health of the HIV-uninfected partner.

Whether the HIV-negative partner should take PrEP if the positive partner is virologically suppressed is a matter of substantial debate. This decision must be individualized and may depend on the HIV-positive partner’s virologic control, condom use, and other partners that the HIV-negative partner may have.