A person seeking pre-exposure prophylaxis (PrEP) will first have to take an HIV test to establish that they are HIV negative.
If someone is apprehensive about testing and receiving their test result in a clinic, a self-test or self-sample kit can be used at home, although the test at the clinic will still need to be done.
A full screening for STIs will be done, including tests for hepatitis B (HVB) and hepatitis C (HVC).
A HVB test will be done to check if someone has active infection, and if positive this will be taken into consideration when discussing treatment options for the HVB infection and the prescribing of PrEP.
If HVC is diagnosed, it is likely that they would be recommended a course of Sofosbuvir. This can be initiated at the same time as PrEP and there are very few negative interactions (contraindications) between Tenofovir and Sofosbuvir.
A kidney function test will be carried out to ensure that the drugs will not negatively affect the kidneys of the user. Depending on the protocols used by the clinic the person gets their PrEP from, kidney function tests will be carried out on a regular basis to assess the ongoing health of the user’s kidneys.
PrEP only protects against HIV and not against other STIs or pregnancy. Other contraceptives to prevent unplanned pregnancy and protective measures against STIs will still need to be used.
Dosing options
Women using PrEP for vaginal/frontal and anal sex take one pill a day.
Men using PrEP for insertive vaginal or insertive or receptive anal sex have the option to follow the daily dosing regimen or choose the ODD/EBD or Ts and Ss regimen.
Daily dosing is recommended for all trans people as there is no data currently to support the other dosing options.
Eligibility
PrEP is available to people from communities with the greatest risk of acquiring HIV, who test HIV negative, and who report episodes of condomless sex with a partner of either unknown HIV status or a partner who is HIV positive and does not currently have an undetectable viral load.
These eligibility guidelines are periodically reviewed and updates will be made available if changes made affect eligibility for PrEP access.
Additional information about PrEP
Stopping PrEP, either temporarily or permanently
This is different from when someone misses a dose accidentally. (In that situation the advice is to take the dose when they remember and continue the dosing regimen they are on as usual.)
It’s perfectly safe for users to stop taking PrEP if they choose to although female users must be informed and aware that they have to keep taking the pills for seven days after the last time they have had sex or their last potential risk of being exposed to HIV.
For male users of PrEP who want to stop, it’s important that they know that they will have to keep taking the pills for at least two days, or up to seven days after the last time they had sex or their last potential risk of being exposed to HIV.
In both cases this is to ensure that the level of drugs in their systems remain high enough to protect them until the risk from this exposure has gone.
Trans men and trans women need to keep taking the pills for seven days after the last time they have had sex or their last potential risk of being exposed to HIV.
Starting PrEP again if someone has stopped or has interrupted the daily dosing regime
If someone has stopped or interrupted their PrEP regimen, it’s safe for them to choose to start taking it again. In this case it is good to let them know that they will have to repeat the same process as when they started taking PrEP for the first time:
- Taking an HIV test to make sure that they are still HIV negative.
- Having a full STI screening, including HVB and HVC tests, to make sure they don’t have active an infection.
- Taking a kidney function test.
Women will again need to take the daily dose for seven days to allow the levels of the drug to build up to protective levels in their bodies before they rely on PrEP to prevent HIV infection.
Men can choose between taking the daily dose for seven days or use the event-based or four-pills-a-week dosing routines to allow the levels of the drug to build up to protective levels before they rely on PrEP only to protect them from HIV.
Trans men and trans women will again need to take the daily dose for seven days to allow the levels of the drug to build up to protective levels in their bodies before they rely on PrEP to prevent HIV infection.
Contraceptives, getting pregnant, breastfeeding and taking hormones
Some people have expressed concerns about how PrEP could affect things like hormonal birth control or if it’s okay to get pregnant or breastfeed if they’re taking PrEP.
When on PrEP it’s possible to:
- Use hormonal contraceptives, including emergency contraception: it’s safe and the drugs do not affect each other. PrEP won’t stop the hormonal birth control pill working for example. Both will work well if they are taken correctly.
- Get pregnant: If someone is trying to get pregnant, it is perfectly okay for them to conceive and carry a baby, PrEP is safe for both them and the foetus. Of course, if they don’t want to get pregnant they will have to carry on using their preferred method of contraception.
- Breastfeed: If someone wants to start or carry on breastfeeding a baby, it’s perfectly safe to do so while they are taking PrEP. It won’t hurt either the parent or the child.
- Take feminising hormone therapy: PrEP will not stop the hormones working, or cause fat redistribution in the face or body.
PrEP interactions with other medications
The drug used most widely for PrEP is a generic version of Truvada, emtricitabine/tenofovir disoproxil fulmarate (TDF).
PrEP does not interact with most other medications and people can also take PrEP and continue to drink alcohol or use recreational drugs. PrEP doesn’t interact or affect the hormonal birth control pill or most other over-the-counter medications.
However, TDF may interact with medications that are taken to treat kidney problems and with NSAIDs including ibuprofen, diclofenac and naproxen potentially leading to kidney function issues. It is suggested that alternatives to NSAIDs such as paracetamol are are used by people on PrEP.
If someone is diagnosed with hepatitis B they can still use PrEP, although only the daily dosing regime is safe for them. Levels of the hepatitis B virus in the body are suppressed by PrEP and on days when PrEP is not taken levels of the virus can ‘rebound’, potentially leading to harmful effects on the liver. As a hepatitis B test is taken as part of the process to access PrEP, options for PrEP access and hepatitis B treatments will be discussed at the clinic.
If hepatitis C is diagnosed, it’s likely that they would be recommended a course of sofosbuvir. This can be initiated at the same time as PrEP and there are very few contraindications between tenofovir and sofosbuvir.
If someone is concerned about PrEP affecting any other medications they may be taking, we encourage them to talk with their GP, the doctor/s that they will see when assessing PrEP or a pharmacist about using PrEP and any effects it may have with other medications they are using.
Liverpool University provides a website where people can check HIV drug interactions themselves.
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