PrEP: Pre-Exposure Prophylaxis
Key points:
PrEP (Emtricitabine/Tenofovir Disoproxil) formerly known as Truvada.
New special authority funding criteria from July 1 2022 - see below.
It is only used for prevention of HIV transmission in non-infected persons. It does not treat or cure HIV in those who already have it. It does not protect against any other STI, thus condoms are still necessary and encouraged.
There are 2 common treatment regimens but the most effective is daily PrEP.
Side effects include GI upset but also kidney and bone impairment are rare risks.
Monitoring of renal function, other sexually transmitted infections, and side effects are encouraged but not mandatory.
Usually very simple to stop treatment.
PrEP consults should ideally include appropriate risk based questioning, past medical history, examination and STI testing, on going encouragement of safe sex practices, and monitoring of side effects.
*See BPAC article for more detailed information.
The Burnett Foundation have a great page of resources for clinicians who wish to prescribe PrEP which includes an online prescribing module
Updated funding criteria/special authority:
From 1 July 2022, the Special Authority criteria for PrEP has been widened. The previous restrictive requirements that only allowed men or transgender persons who engage in high risk behaviours and scenarios to access PrEP have been removed. The new criteria more simply requires a negative HIV result and an appropriate clinical indication as judged by the prescriber. The need for regular 3 monthly follow up visits with full STI screening has also been removed and the updated renewal is now valid for 24 months. These changes to both the eligibility criteria and frequency of testing for renewals will significantly reduce access barriers to effective HIV prevention medications in Aotearoa.
Initial application from any relevant practitioner. Approvals valid for 24 months for applications meeting the following criteria:
Both:
Patient has tested HIV negative and is not at risk of HIV seroconversion; and
The Practitioner considers the patient is at risk of HIV exposure and use of PrEP is clinically appropriate.
Renewal from any relevant practitioner. Approvals valid for 24 months for applications meeting the following criteria:
Both:
Patient has tested HIV negative and is not at risk of HIV seroconversion; and
The Practitioner considers the patient is at risk of HIV exposure and use of PrEP is clinically appropriate.
*Patients not eligible for PHARMAC funded PrEP (for example visitors or short term working visa holders) can self-fund from a NZ pharmacy or can self import PrEP under the self importation scheme. Click here for more information.
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Daily treatment
99% effective if used daily. This is the most effective regime. Even 4 tablets per week can still give 96% protection so don’t stress too much about a missed pill.
Needs to be taken for at least 7days before full effectiveness is reached
Non-daily PrEP/ on-demand = 2:1:1
Only for cis-gender MSM whose HIV risk is from anal sex rather than injecting drug use
2 pills at least 2hrs before sex, one pill 24hrs after and then again 24hrs after that
If repeated sexual activity, then continue with 1 pill daily until 48h after last sexual contact
Better for infrequent encounters or organised events - cruises
Not as effective as daily treatment but still ~92-95% effective
*If a dose is missed, advise the patient that they should take a tablet as soon as they remember, unless there are fewer than 12 hours until the next dose, in which case the missed dose can be skipped
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20% risk of mild symptoms such as nausea, GI upset, headaches but these are usually found early on / within 1 month of starting.
Rare but more worrisome risk of bone density loss and renal impairment - likely only 1-2% reversible decrease in bone density, consider DEXA if high risk.
Again, this does not protect from other STIs and is not 100% effective so condoms and other safe sexual practice should be followed.
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New special authority criteria only require a new approval every 24 months. However, regular monitoring of side effects, STI risk, and safe sex practices should still be encouraged. This includes:
Annual renal check up with urine microalbumin and renal function bloods.
Annual calcium/phosphate and bone health checks.
Full 3 monthly STI screening - Chlamydia & Gonorrhoea rectal and throat swab, urine and bloods for HIV & Syphilis.
Click here for a downloadable PDF with more information.
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You can stop at any time, but you will obviously not have the benefit of HIV prevention. If you wish to re-start you will again need to use for 7days before effective protection is achieved.
Only cis-gender men who have sex with men (MSM) taking daily or on-demand PrEP can stop 48 hours after last exposure. Non MSM patients need to continue taking PrEP for a further 28days after last sexual contact.
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Click on the topics below to be redirected to further resources.
Full PrEP sexual health check up
Despite the simplifications in PrEP prescribing and monitoring requirements it would still be advisable to do a thorough sexual health check up at least at the outset. Below we will go through a full sexual health check up for a cis gender MSM client who wishes to consider PrEP. We would encourage prescribers to consider these at initiation and also periodically throughout its utilisation as appropriate.
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It is important to avoid asking questions out of curiosity. However, it is also important to ask some specific questions as listed:
Regular partner, other contacts
Last sexual intercourse or encounter
If <72 hours, consider PEP
Repeat HIV testing ~1 month due to risk of late seroconversion
Consider repeating other STI screening depending on risk
Sexual practices i.e. oral, insertive, receptive etc
Drug use: meth, IV drugs
High risk behaviours or scenarios: prison tattoos, sex workers, drug parties
Current symptoms
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Renal impairment - diabetes, HTN, age >40, renal disease - PrEP is contraindicated in people with an estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73m2.
HIV and other STI status.
Bone pathology or risk factors: alcohol excess, low BMI, age.
Medication interactions: Nephrotoxic medicines or those that compete for active tubular secretion may increase serum concentrations of PrEP.
Immunisation status - Hep A/B - if not immune then suggest vaccination.
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Baseline BP and weight
Annual renal function, urine PCR
HIV screening
Hepatitis screen: A, B, C
Syphilis screen
Pregnancy test if warranted
First morning urine test - chlamydia/gonorrhoea
Throat AND rectal NAAT swabs for chlamydia/gonorrhoea
*HIV seroconversion can take up to 1 month so re-test if last sexual contact within last few weeks
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Side effects/risks covered
Daily PrEP or 2:1:1 regimens discussed
Safe sexual practices encouraged - condoms are strongly recommended, particularly for at least the first 7days of treatment
Regular STI check ups encouraged
Provide prescription with SA number once HIV result back
Case Example:
Mr T. is a 30yo cis gender MSM who wants to start PrEP. He has heard about it from friends and was advised to take it to reduce his risk of HIV infection. He has had multiple episodes of anal intercourse in the last few months, both insertive and receptive, and on occasions has not worn a condom. He is not an IV drug or methamphetamine user and has no current STI symptoms or infection he is aware of. His last sexual encounter was a week ago where he had receptive anal intercourse with a partner of unknown status. He is otherwise fit and healthy and has no medical issues or medications. He is unaware of his full immunisation status but thinks he had all childhood immunisations.
Clinical points:
Meets eligibility criteria for PrEP and would likely benefit from HIV prevention.
No significant past medical history that would stop him from using PrEP.
Last sexual encounter was only a week ago so will need repeat testing in 1 month to confirm negative HIV status.
Arrange for STI check and advise to use condoms or avoid sex for at least the next week until results are back and script can be organised.
You discuss with him PrEP use including risks, side effects, monitoring as well as safe sex practice. You advise him you will contact him with results and can send a script if results are satisfactory. You give him a further HIV serology blood test to do in 1 month. Results come back a few days later:
He is not immune to Hep B
Hep A, C, HIV, syphilis serology are negative
Chlamydia and gonorrhoea NAAT tests are normal
Further actions:
Advise him that HIV and STI results are normal and he is eligible for PrEP.
Send script with special authority number attached.
Book in with nurse to consider Hep A vaccination and Hep B booster.
New criteria requires him to be seen every 2 years for PrEP SA renewal.
Preferable STI and sexual health checks every 6-12 months.