Pre-Exposure Prophylaxis (PrEP)

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Pre-exposure prophylaxis, or PrEP, is when people at high risk for HIV take HIV medicines daily to lower chances of getting infected.


PrEP involves the use of antiretroviral (ARV) drugs before HIV exposure by people who are not infected with HIV to block the acquisition of HIV. WHO recommends oral PrEP containing Tenofovir (TDF) with either Emtricitabine (FTC) or Lamivudine (3TC) to be offered as an additional prevention choice for people at substantial risk of HIV infection as part of combination HIV prevention approaches.

Considerations for PrEP

  • The combination of TDF+XTC (Emtricitabine or Lamivudine) is active against Hepatitis B infection thus discontinuation of TDF+XTC requires close monitoring in those infected with Hepatitis B due to the concern for rebound viremia.
  • Persons with osteopenia/osteomalacia/osteoporosis may be at risk of bone loss associated with TDF.
  • PrEP efficacy has not yet been established in pregnancy and breastfeeding, therefore its use in this population is NOT recommended.
  • TDF should not be co-administered with other nephrotoxic drugs, e.g. aminoglycosides.
  • Standard TB medication does not interact with PrEP drugs and there is no need for dose adjustments.
  • Clients on MDR-TB medications may have increased risk of renal side effects. PrEP should therefore be avoided.
  • Other prevention methods should be recommended and PrEP screening should be delayed until the end of MDR-treatment.
  • Standard hormonal contraception does not affect PrEP effectiveness, nor does PrEP affect contraceptive effectiveness.
  • PrEP clients must be routinely tested for HIV infection, and cART offered immediately if the PrEP user seroconverts.
  • PrEP is not 100% effective at preventing HIV and clients need to be counselled that they should use other prevention methods as well.

Eligibility Criteria

  • No suspicion of acute HIV infection
  • Test HIV negative at a health facility
  • Interested in PrEP and willing to be adherent
  • Able to attend regular 3-month reviews and HIV testing
  • Able to concomitantly apply other prevention methods such as barriers to prevent the transmission of other STIs
  • Willing to stop taking PrEP when no longer eligible.


And: at substantial risk for HIV infection, defined as engaging in one or more of the following activities within the last six months:

  • Vaginal/anal intercourse without condoms with more than one partner
  • Sexually active with a partner who is known to be HIV positive or at substantial risk of being HIV positive
  • Sexually active with an HIV-positive partner who is not on effective treatment (defined as on cART for > 6 months and virally suppressed)
  • History of STI
  • History of PEP use
  • Sharing injection material or equipment

PrEP may also be considered for key populations (as defined by the 2017 NASF) or by persons self-selected as high-risk for HIV acquisition. Such persons should meet the eligibility criteria above.

Recommendations

  • PrEP should be taken for a minimum of 7 days in men, 21 days in women to achieve maximal protection from HIV acquisition before engaging in high-risk sexual exposure and must be continued as long as risky exposure persists or one remains negative HIV testing is required before PrEP is offered
  • Repeat HIV testing every 3 months is mandatory while a client is on PrEP
  • The frequent HIV testing during PrEP use should also ideally become an opportunity for STI screening and management.
  • Those who seroconvert while on PrEP should be immediately switched to a standard first-line regimen
  • PrEP should be provided as part of the combination prevention package (condom use, HTS, family planning, STI screening, etc.)

Lab Tests before PrEP

  • HIV test (only HIV-negative partners should be on PrEP)
  • Creatinine (or urinalysis if creatinine not available)
  • ALT
  • RPR/RST
  • Repeat HIV testing is recommended while PrEP is taken every three months
  • Hepatitis B (those with positive results should be on lifelong TDF+XTC to treat HBV)

ARV regimen to be used for oral PrEP

  • Tenofovir Disoproxil Fumarate in combination with Emtricitabine (TDF+FTC) is preferred for PrEP.
  • However, if Emtricitabine is not available, Lamivudine in combination with Tenofovir (TDF+3TC) may be used for PrEP.

Lab Monitoring while on PrEP

  • Creatinine at 1 month, 2 months, every 3 months for the first 12 months then annually thereafter
  • ALT every 3 months for the first 12 months then annually thereafter
  • Repeat HIV testing is recommended while PrEP is taken at one month and every 3 months
  • Necessary lab tests as per indication
  • Pregnancy test (especially if the PrEP regimen is TAF-based).

Adherence Support on PrEP

  • Support for adherence should include information that PrEP is highly effective when used with strict adherence.
  • PrEP users should be advised that PrEP only becomes effective after 7 days (21 days in women) and must be continued as long as risky exposure persists or one remains negative.
  • Brief client-centred counselling that links daily medication use with a daily habit (such as waking up, going to sleep, or a regular meal) may be helpful.
  • Special programmes to facilitate adherence among particular groups—such as young people and women—may be needed.
  • Support groups for PrEP users, including social media groups (e.g. https://www.facebook.com/groups/PrEPFacts), maybe helpful for peer-to-peer sharing of experience and challenges.
  • People who start PrEP may report side effects in the first few weeks of use. These side effects include nausea, abdominal cramping, or headache, are typically mild and self-limited, and do not require discontinuation of PrEP.People starting PrEP who are advised of this start-up syndrome may be more adherent.

When to Stop PrEP

  • PrEP can be discontinued if a person taking PrEP is no longer at risk and when this situation is likely to be sustained (i.e., no longer engaging in any high-risk behaviours as defined above).
  • PrEP can be discontinued after 4 weeks of elimination of the risk exposure.
  • Significant side effects or if the creatinine clearance decreases to <50mL/min.
  • If in a serodiscordant relationship, the HIV positive partner has been on ART for more than 6 months, is known to be virally suppressed, and there are no other partners, then the HIV negative partner on PrEP may discontinue therapy. However, for pregnant or breastfeeding women, PrEP should be continued.

Note: For Step-by-Step guide to PrEP use, refer to the 2020 Zambia Consolidated HIV Treatment Guidelines.

PrEP considerations for Pregnant and Breastfeeding Women Pregnant and breastfeeding women, often remain at substantial and increased risk of HIV acquisition during pregnancy and breastfeeding.

There is no safety-related rationale for disallowing or discontinuing PrEP use during pregnancy and breastfeeding for HIV-negative women who are receiving PrEP and remain at risk of HIV acquisition. The guidelines conclude that in such situations the benefits of preventing HIV acquisition in the mother, and the accompanying reduced risk of mother-to-child HIV transmission outweigh any potential risks of PrEP, including any risks of fetal and infant exposure to TDF and XTC in PrEP regimens. Active toxicity surveillance for ARV use during pregnancy and breastfeeding is highly recommended.

Although there is limited experience with the use of PrEP in antenatal and postnatal care services, it is an important new HIV prevention method.

Indications for PrEP in Pregnant and Breastfeeding Women

  1. A woman taking PrEP who subsequently becomes pregnant and remains at substantial risk of HIV infection
  2. A pregnant or breastfeeding HIV-negative woman who is or perceives herself to be at substantial risk of HIV acquisition
  3. A pregnant or breastfeeding HIV-negative woman whose partner is HIV-positive
  4. An HIV- negative woman who is trying to conceive if her partner is HIV-positive.

In such cases, PrEP combined with screening for acute infection, adherence counselling, safety monitoring and HIV retesting every three months, in addition to other existing HIV prevention options, including condoms, should be offered.

PrEP Regimen in Pregnant and Breastfeeding Women

TDF + XTC in combination with other ARVs for HIV treatment.

TAF + FTC can be used in patients with CrCl between 30 and 50mL/min, though TAF is not currently recommended for use in patients with TB or pregnancy.

Note:

  • PrEP should be provided as part of a comprehensive package: PrEP is part of a package of combination HIV prevention and other services that include HIV testing services, assisted partner notification, provision of male and female condoms and lubricants, contraception choices and screening and treatment of STIs.
  • A woman’s risk may vary over time as circumstances change. Women should be supported to start and to stop PrEP if their HIV risk changes. The risk for HIV acquisition is not constant.
  • PrEP can be used with hormonal contraception. Recommended PrEP regimens do not appear to alter the effectiveness of hormonal contraception.
  • PrEP is not for everyone: It is a choice, and women should be making an informed decision based on their risk for HIV. All women should be counselled on the range of HIV prevention modalities that they can choose from to minimize the risk of HIV acquisition during pregnancy.
  • Active surveillance of pregnant and breastfeeding women receiving PrEP is needed to identify and record adverse pregnancy and infant outcomes. Clients on PrEP need to be followed up at the clinic for routine monitoring.