How Can I Help Patients Take PrEP Consistently?

Make pre-exposure prophylaxis (PrEP) a part of your patients’ HIV prevention plans.
Offer PrEP medication and dosing options to meet patients’ needs.

Daily Oral PrEP. Oral PrEP is approved by the US Food and Drug Administration (FDA) to be taken once daily by mouth. When taken as prescribed, oral PrEP is about 99% effective in preventing HIV from sex1-3 and at least 74% effective in preventing HIV from injection drug use.4,5 High adherence to daily oral PrEP is required for it to be effective.1,2,6 A few cases of HIV infection have been reported among gay, bisexual, and other men who have sex with men (collectively referred to as MSM) whose high adherence to PrEP was verified. These rare cases show that the risk of HIV when oral PrEP is taken as prescribed is extremely low.

Based on existing research, oral PrEP reaches maximum drug levels associated with protection from HIV for receptive anal sex at about 7 days of daily use. For receptive vaginal sex and injection drug use, oral PrEP reaches maximum drug levels at up to about 21 days of daily use. There are no data available about how long it takes for PrEP to reach protective levels for insertive vaginal and anal sex.

2-1-1 Dosing of Oral PrEP.

Oral PrEP with emtricitabine/tenofovir disoproxil fumarate (F/TDF) can be prescribed off-label using “2-1-1” dosing for adult MSM. This is also known as event-driven, intermittent, on-demand, or coitally timed PrEP. When using 2-1-1 dosing, the patient takes F/TDF doses based on when they plan to have sex: two pills 2–24 hours before sex, one pill 24 hours after the first two-pill dose, and one pill 48 hours after the first two-pill dose.

Off-label 2-1-1 dosing is not approved by the FDA and not recommended by the Centers for Disease Control and Prevention (CDC). However, it can be prescribed to MSM who meet the following criteria:

  • Request non-daily dosing.
  • Have sex infrequently (e.g., less often than once a week).
  • Can anticipate sex (or delay sex) to permit the doses at least 2 hours prior to sex.

2-1-1 dosing should not be prescribed for MSM who might have problems adhering to a complex dosing regimen (e.g., adolescents, patients with an active substance use disorder).

Injectable PrEP may be appropriate for people who have problems taking oral PrEP as prescribed.

Injectable PrEP.

When taken as prescribed, injectable PrEP with cabotegravir (CAB) is over 99% effective at reducing the risk of getting HIV from sex.7,8 CAB injections may be especially useful for people who: 

  • Have problems taking oral PrEP as prescribed. 
  • Prefer getting a shot every 2 months instead of taking oral PrEP. 
  • Have serious kidney disease that prevents use of oral PrEP medications.  

CAB is given as an intramuscular injection initiated as a first injection followed by a second injection 1 month after the first. Injections are continued every 2 months thereafter. A 4-week lead-in period of 30 mg daily oral CAB prior to the first injection is optional for patients who are worried about side effects.  

Returning for bimonthly injections is necessary to maintain protective levels of medication. In trials, HIV infections have occurred among people who delayed receiving their injections for several months. There are no available data for CAB to estimate how long it takes to reach maximal protection against HIV acquisition. 

Connect patients with resources to pay for PrEP medication, clinical visits, and lab tests.

PrEP is now more accessible than ever. The US Preventive Services Task Force issued a Grade A recommendation for PrEP. This means that most private health plans and Medicaid programs are required to cover PrEP services without cost sharing, such as copays or deductibles. Prior authorization may be required.
Additionally, some states have their own PrEP assistance programs. Some cover medication, some cover clinical visit and lab costs, and some cover both. To learn more, consult NASTAD’s list of state PrEP assistance programs.

Uninsured patients can be assisted to apply for Medicaid or Affordable Care Act (ACA) marketplace insurance programs if they are eligible. To assist patients in choosing an ACA plan for PrEP coverage, visit the NASTAD PrEP Cost Calculator.

Ready, Set, PrEP makes oral PrEP medication available at no cost to patients without HIV who have a prescription but no insurance coverage for oral PrEP medication, regardless of income. To learn more, call toll-free 1-855-447-8410 or visit the Ready, Set, PrEP website.

The Gilead Sciences Advancing Access program offers eligible patients assistance with medication costs for oral PrEP.

ViiVConnect offers a medication assistance program to help patients pay for CAB injections.

Conduct required ongoing assessments for patients on PrEP.

Prescribe PrEP as part of a combination prevention plan. At minimum, while patients are on PrEP, CDC guidelines recommend that health care providers providers implement support and ongoing assessments. Click through each tab below for more information about these recommendations.

  • Repeat HIV antigen/antibody and HIV-1 RNA tests and assess for signs or symptoms of acute infection to confirm that patients are still HIV negative.
  • Provide a prescription or refill authorization of daily oral PrEP medication for no more than 90 days (until the next HIV test).
  • Assess and provide support for medication adherence and risk-reduction behaviors.
  • Test sexually active patients with signs or symptoms of sexually transmitted infections (STIs). Screen asymptomatic MSM at high risk for recurrent bacterial STIs (oral, rectal, urine, blood). Examples of MSM who should be screened include those with syphilis, gonorrhea, or chlamydia at prior visits or multiple sex partners.
  • Provide access to sterile needles/syringes and substance use disorder treatment services for people who inject drugs.
  • Respond to new questions and provide any new information about PrEP use.
  • Monitor estimated creatinine clearance (eCrCl) for patients age ≥50 years or who had an eCrCl <90 mL/min when they started oral PrEP.
    • If there are other threats to kidney safety (e.g., hypertension, diabetes), kidney function may need to be monitored more often or checked using additional tests (e.g., urinalysis for proteinuria).
    • A rise in serum creatinine is not a reason to withhold PrEP if eCrCl remains ≥60 mL/min for F/TDF or ≥30 mL/min for emtricitabine/tenofovir alafenamide (F/TAF).
    • If eCrCl is declining steadily (but still ≥60 mL/min for F/TDF or ≥30 mL/min for F/TAF), consult with a nephrologist, if needed, or evaluate other possible threats to kidney health.
  • Screen sexually active people for STIs (vaginal, oral, rectal, urine, as indicated; blood):
    • Syphilis for all PrEP users.
    • Gonorrhea for all PrEP users.
    • Chlamydia for MSM and transgender women, even if asymptomatic.
  • Assess interest in continuing or stopping PrEP.
  • Monitor eCrCl for all patients continuing on oral PrEP medication.
  • Monitor triglyceride and cholesterol levels and weight for patients prescribed F/TAF for PrEP.
  • Screen heterosexually active people for chlamydia (vaginal, urine), even if asymptomatic.

For patients on injectable PrEP

  • Test for HIV with antigen/antibody and HIV-1 RNA assays and assess for signs or symptoms of acute infection.
  • Administer CAB injection.
  • Respond to new questions.
  • Provide medication adherence and behavioral risk-reduction support.
  • Test for HIV with antigen/antibody and HIV-1 RNA assays and assess for signs or symptoms of acute infection.
  • Administer CAB injection.
  • Provide access to sterile needles/syringes and substance use disorder treatment services for people who inject drugs.
  • Respond to new questions and provide any new information about CAB for PrEP.
  • Discuss the benefits of persistent CAB for PrEP use and adherence to schedule injection visits.
  • Conduct bacterial STI screening for MSM and transgender women who have sex with men (oral, rectal, urine, blood).
  • Screen all heterosexually active people for bacterial STIs (vaginal, rectal, urine, as indicated; blood).
  • Assess desire to continue PrEP injections.
  • Screen heterosexually active people for chlamydia (vaginal, urine), even if asymptomatic.
Support patients who wish to stop using PrEP with other methods to protect themselves from HIV.

Oral PrEP. Discuss how to safely discontinue and restart daily PrEP use with patients both when starting PrEP and when discontinuing PrEP. Protection from HIV infection will wane over 7–10 days after ceasing daily oral PrEP use. Because some patients can acquire HIV soon after stopping PrEP, providers should assess ongoing risk for HIV and discuss other prevention methods if HIV exposure is anticipated, including nonoccupational post-exposure prophylaxis (PEP).

Injectable PrEP. CAB levels slowly wane over many months after injections are discontinued. At some point during this “tail period,” CAB levels will fall below a protective threshold and persist for some time at nonprotective levels. For these reasons, patients discontinuing CAB injections who may be at ongoing risk should be provided with another highly effective HIV prevention method during the months following their last injection. Providers should follow these steps when a patient discontinues or misses CAB injections:

  • Counsel patients about the risk of developing drug-resistant HIV during declining CAB levels (the “tail period”) after CAB injections are stopped or when injections are missed.
  • Assess ongoing risk for HIV exposure and prescribe daily oral PrEP within 8 weeks after the last CAB injection or other prevention methods if HIV exposure is anticipated, including nonoccupational PEP.
  • Continue follow-up visits quarterly for 12 months. Conduct antigen/antibody and HIV-1 RNA tests at each quarterly follow-up visit after stopping CAB injections.

For more information about the “tail period” after CAB injections are stopped, see page 53 of A Clinical Practice Guideline for PrEP.

Take additional steps to confirm HIV status if a PrEP patient has an ambiguous HIV test result.

If a patient has unclear HIV test results at a follow-up visit, providers can follow these steps to confirm the patient’s true HIV status:

  • Wait 5–7 days and then draw a new blood specimen for repeat laboratory HIV testing using both an HIV antigen/antibody test and an HIV-1 RNA assay.
  • If the repeat testing results show the patient has HIV, link the patient to HIV care and treatment. If the repeat testing results confirm that the patient does not have HIV, PrEP can be continued.
  • If the results are still ambiguous, contact the National Clinician Consultation Center PrEPline at 1-855-448-7737 (Monday–Friday, 9:00 AM–8:00 PM ET) to get further testing advice and for linkage to a laboratory that can do specialized testing to confirm their HIV status.

While HIV status is being confirmed, providers have the following antiretroviral management options:

Managing PrEP use while confirming HIV status after an ambiguous HIV test result

For patients using oral PrEP:

  • Continue oral PrEP medication: Because PrEP is highly effective, it is unlikely that a patient who takes PrEP medication as prescribed will get HIV. If the patient does have HIV, continuing PrEP may help to suppress the virus but may also increase the probability that the patient will develop drug-resistant HIV. If this occurs, there are well-tolerated and highly effective treatment regimens available.
  • Prescribe a third drug as PEP for 28 days: This option provides a fully suppressive treatment regimen without the need to diagnose the patient with HIV, which can be difficult to undo if further testing shows the patient does not have HIV. If the patient is found to have HIV, this regimen can be considered early antiretroviral initiation and be continued. This option is especially applicable for patients who may not have taken their daily oral PrEP medication as prescribed.
  • Stop oral PrEP medication for 1–2 weeks: If the patient has HIV, briefly stopping PrEP allows time for HIV replication to occur and increases the likelihood that an HIV test will detect the virus, if it is present. Note that stopping oral PrEP will leave the patient with less protection from HIV because oral PrEP levels wane over 7–10 days after the medication is stopped.

For patients using CAB injections:

  • Pause CAB injections until testing shows that the patient does not have HIV.
  • During the 1–2 weeks needed for additional HIV testing to determine HIV status, CAB is likely to remain at protective levels.
  • If the patient has HIV, start HIV treatment immediately.
  • If the patient does not have HIV, resume CAB injections every 2 months.
How to Manage a Patient Who Gets HIV While Taking PrEP.

Once additional laboratory tests have confirmed the patient has HIV, take the following steps:

  • Initiate treatment or refer for comprehensive HIV care.
  • Counsel the patient about how to prevent HIV transmission to others and improve their own health.

Report the new HIV infection to the local health department.

Provide PrEP services by telehealth, if needed.

The recent expansion of telehealth visits to replace some or all in-clinic visits has led to adaptations for the provision of PrEP. These adaptations can include the following procedures:

  1. Providers may conduct PrEP screening, initiation, or follow-up visits by phone or web-based consult with patients.
  2. Regular HIV testing should be continued for patient safety. Lab-only visits for HIV testing and other indicated tests for the provision of PrEP are strongly preferred.
    • Only in situations where no laboratory or clinic visits are possible (e.g., local emergencies or lock-downs), patients may conduct self-testing using an oral swab-based test. This type of HIV test is usually not recommended for PrEP patients because it may not detect recent HIV infection in people taking PrEP medications.
  3. Once HIV-negative status is confirmed, if prescribing oral PrEP, providers can consider writing a prescription for a 90-day supply of medication rather than a 30-day supply with two refills. This will help patients minimize trips to the pharmacy and facilitate oral PrEP adherence.

1 Grant RM, Anderson PL, McMahan V, et al. An observational study of pre-exposure prophylaxis uptake, sexual practices, and HIV incidence among men and transgender women who have sex with men. Lancet Infect Dis. 2014;14(9):820-829.

2 Castillo-Mancilla JR, Zheng J-H, Rower JE, et al. Tenofovir, emtricitabine, and tenofovir diphosphate in dried blood spots for determining recent and cumulative drug exposure. AIDS Res Hum Retrovir. 2013;29(2):384-390.

3 Mayer KH, Molina, J-M, Thompson, MA, et al. Emtricitabine and tenofovir alafenamide vs emtricitabine and tenofovir disoproxil fumarate for HIV pre-exposure prophylaxis (DISCOVER): primary results from a randomized, double-blind, multicentre, active-controlled, phase 3, non-inferiority trial. Lancet. 2020;396(10246):239-254.

4 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.

5 Martin M, Vanichseni S, Suntharasamai P, et al. The impact of adherence to preexposure prophylaxis on the risk of HIV infection among people who inject drugs. AIDS. 2015;29(7):819-824.

6 Cottrell ML, Yang KH, Prince HMA, et al. A translational pharmacology approach to predicting outcomes of preexposure prophylaxis against HIV in men and women using tenofovir disoproxil fumarate with or without emtricitabine. J Infect Dis. 2016;214(1):55-64.

7 Landovitz RJ, Donnell D, Clement ME, et al. Cabotegravir for HIV prevention in cisgender men and transgender women. N Engl J Med. 2021;385(7):595-608.

8 HPTN 084 study demonstrates superiority of CAB LA to oral TDF/FTC for the prevention of HIV. HPTN: HIV Prevention Trials Network; November 9, 2020. Accessed May 3, 2022.  

9 Centers for Disease Control and Prevention, US Public Health Service. Preexposure prophylaxis for the prevention of HIV infection in the United States—2021 update: a clinical practice guideline. Accessed January 7, 2022. /hiv/pdf/risk/prep/cdc-hiv-prep-guidelines-2021.pdf