PrEP
What is HIV PrEP?
PrEP stands for Pre-Exposure Prophylaxis.
HIV PrEP is taken by HIV negative people before having sex (pre-exposure) and after sex, to prevent HIV (this is called prophylaxis).
HIV PrEP is a combination tablet containing two drugs: tenofovir and emtricitabine. These medicines are widely used to treat HIV. They have been licensed for use as PrEP in Europe since August 2016.
For the remainder of this page, HIV PrEP is referred to as ‘PrEP’. In the context of this page ‘PrEP’ relates to PrEP for HIV prevention only.
How well does PrEP work?
PrEP has been shown in many studies to be safe and highly effective at preventing HIV. When taken correctly PrEP has been found to be more than 95% effective.
In PrEP studies where HIV infections have happened, most of those who became HIV positive were not taking the medication properly at the time they contracted HIV.
If you decide to use PrEP, it is important that you do so with support from a healthcare provider and that you understand how to take PrEP correctly.
PrEP and other sexually transmitted infections (STIs)
PrEP does not protect against other STIs, such as syphilis, chlamydia, gonorrhoea and hepatitis C. PrEP users can combine condoms and PrEP to reduce the risk of contracting other STIs.
Regular STI testing at least every three months is recommended for people taking PrEP.
Vaccination against hepatitis A and B is recommended for all gay, bisexual and other men who have sex with men (MSM) and people who inject drugs. HPV vaccination is recommended for MSM up to and including 45 years of age to protect against genital warts and HPV-associated cancers. These are available for free through public STI clinics.
Getting PrEP in Ireland
If you are HIV negative and don’t always use condoms for anal or vaginal sex, then you may be at risk of HIV.
From October 2019, PrEP is available through the HSE free of charge to those who are considered to be at substantial risk of contracting HIV through sex.
PrEP is available in some public sexual health services and through some general practice (GP) and private providers. For further information on where PrEP is available, see sexualwellbeing.ie.
PrEP is dispensed through community pharmacies and you will need a drug payment scheme (DPS) or medical card to access free PrEP through the HSE. Anyone with a PPSN can apply for a DPS card. Please see www.myDPS.ie, and download an application form here, or ask your pharmacist.
If you don’t have a PPSN, visit citizensinformation.ie.
Who is eligible for free PrEP through the HSE?
To avail of free PrEP through the HSE you need to:
· test negative for HIV
· be able to attend for a check-up at least every three months.
You also need to meet at least one of the following criteria:
· you are having sex without condoms with HIV-positive partners who
o are not on HIV treatment OR
o are on treatment but not virally suppressed (do not have an “undetectable” viral load)
· you are a man who has sex with men (includes transgender men who have sex with men) or a transgender woman who has sex with men, who
meets any one of the following:
o had anal sex without condoms with more than one partner in the last 6 months
o had a sexually transmitted infection (STI) in the last year
o used HIV post-exposure prophylaxis (PEP) in the last year
o used recreational drugs for sex (also known as ChemSex) in the last 6 months
o you are a heterosexual man or woman who is considered to be at substantial risk
of contracting HIV through sex, by a specialist STI or infectious diseases doctor.
What if I am not eligible for free PrEP?
If you do not meet the criteria for free PrEP and decide to pay for PrEP yourself, this can be purchased through community pharmacies with a prescription. You should be aware of the situations where PrEP is not recommended, see below.
Regardless of how you are getting PrEP, we recommend that, for your safety, you should follow the same assessment and monitoring guidance that is recommended in the later sections of this page.
Who should not take PrEP?
PrEP should not be used:
· If you are HIV positive.
PrEP is usually not necessary:
· If you are only having sex with HIV-positive partners who are on treatment and have
an undetectable viral load.
· If you are using condoms consistently and happy to continue doing so.
If you are buying PrEP online
It is possible to buy generic PrEP products over the internet. In Ireland, it is illegal for a person to source prescription medication without a prescription and it is illegal for medication to be supplied by mail order, including over the internet. The Health Products Regulation Authority (HPRA) provide information for the public on the risks of buying medicines online.
Side effects, drug interactions and resistance
Does PrEP have side effects?
Most people taking PrEP do not report any major side effects.
However, like all medicines, PrEP has the potential to cause side effects. Less than 1 in 10 people taking PrEP report mild nausea, diarrhoea, bloating or headache. These side effects usually stop within the first month.
Occasionally PrEP can cause more serious side effects. PrEP can also affect your kidneys, which is why monitoring is important. In the small proportion of people taking PrEP who developed reduced kidney function, these changes usually reversed on stopping PrEP. This risk is higher if you are aged 40 years and over or if you already have reduced kidney function when you start PrEP.
PrEP can also reduce bone density by between 1% and 2%, causing slight thinning of the bones. This loss reverses after PrEP is stopped. This side effect might be more important if you already have low bone density related to other factors. It might also be important if you are younger than 30 years as your bones are still developing.
Does PrEP interact with any other medications?
Tenofovir and emtricitabine don’t interact with many other medicines. (Interaction means that two or more drugs combined together can cause problems or side effects).
You should always tell your doctor (including your GP) if you are prescribed other medicines. You can also ask a pharmacist. Tell them that you are taking PrEP so that they can check for any interactions, including with over-the-counter meds.
One important consideration is taking tenofovir at the same time as non-steroidal anti-inflammatory drugs (NSAIDs), especially diclofenac. Together these can cause kidney problems. Other medicines from within this class include ibuprofen and naproxen. Avoid using these medicines if you are taking PrEP, or let your doctor know if you need to take them.
For transgender people taking PrEP, there is no reason to expect PrEP will change the effectiveness of hormone therapy. However there is some evidence that feminising hormones can affect the levels of PrEP in your system, so it is advised that transgender women who are using hormone therapy use daily PrEP only and do NOT use event-based dosing.
PrEP and drug resistance
If you become HIV positive while taking PrEP, there is a small risk of developing drug resistance to one or both drugs. This means that these drugs will not work as well against HIV.
In PrEP studies, very few people became HIV positive whilst taking PrEP. In those who did, less than 1 in 20 developed drug resistance.
The possibility of drug resistance increases if you:
· Start PrEP without knowing that you are already HIV positive. This is why it is so
important to have a HIV test before you start PrEP.
· Take a break from PrEP and don’t check your HIV status before re-starting.
· Don’t take PrEP correctly and become HIV positive.
· Come in contact with drug-resistant HIV. This is very rare: globally, only two cases have been reported of PrEP not working where the person came in contact with drug-resistant HIV.
Testing and monitoring
Before you start PrEP
There are a few tests that you will need before you start PrEP.
1. HIV
It is essential to have a 4th generation HIV test before or as you start PrEP. A blood sample will be taken, usually from your arm, and sent to a laboratory. This test has a window period of approximately four weeks.
The window period is the time between when you may have been exposed to HIV, and the point when the test will give an accurate result. During the window period you can be infected with HIV but still have a negative HIV test.
If there is a chance that you have been exposed to HIV in the last four weeks, tell your healthcare provider. There may be a need to do additional blood tests and get you to have a repeat HIV test 4 weeks after starting. This is to ensure that an early infection is not missed.
If you have had a recent HIV risk and have developed flu-like symptoms, this may be a sign of HIV seroconversion (this is when the immune system produces antibodies in response to a recent HIV infection). In this situation it may not be safe to start PrEP until the result of your HIV test is back from the laboratory and HIV has been ruled out.
If you are starting PrEP after PEP (post-exposure prophylaxis), it is best to start immediately after you finish the course of PEP. There is no need to delay starting PrEP after PEP. Ideally you should have a 4th generation HIV blood test around the time you finish PEP/start PrEP, plus another HIV blood test four weeks after starting PrEP.
Sometimes a rapid HIV test is done in addition to the laboratory HIV test. If the rapid test is negative it may be possible to start PrEP on the day you are first seen regarding PrEP. This will be discussed with you in greater detail by your healthcare provider.
2. Hepatitis B
It is essential to test for hepatitis B because PrEP medicines are active against both HIV and hepatitis B. Taking PrEP if you have undiagnosed Hepatitis B could be harmful to you.
You can still use PrEP if you have hepatitis B, but it needs to be used more carefully.
If you have hepatitis B, you need to take daily PrEP with medical advice and monitoring, especially if you want to stop. Event based dosing (EBD) is not suitable if you have hepatitis B (or if you don’t know your hepatitis B status).
This is a good time to be vaccinated, or to boost a previous vaccine.
Hepatitis A and B vaccination is recommended for gay, bisexual and other men who have sex with men (MSM) and people who inject drugs (PWID).
3. Kidney function
Kidney monitoring involves a blood test for creatinine, and sometimes a urine test for protein. These should ideally be done just before or on the day you start PrEP.
4. Sexually transmitted infections (STIs)
You should have STI testing, which includes testing for syphilis, chlamydia, gonorrhoea and hepatitis C.
In addition to hepatitis A & B vaccination, the HPV vaccination is recommended for gay, bisexual and other men who have sex with men (MSM) up to and including 45 years of age. The HPV vaccination protects against genital warts and HPV-associated cancers.
5. Pregnancy
Pregnancy status should be established in people who can become pregnant and may be reviewed again during follow up as required.
Once you are taking PrEP
Once you have started PrEP, it is essential to monitor for HIV and STIs and check your kidney function on a regular basis. Although side effects are rare, the clinic monitoring will help to identify any potential problems at an early stage.
After one month
If it is your first time taking PrEP, you may be offered an appointment after one month to make sure you are okay with the medication or if you need any more tests or vaccinations.
Every 3 months
· have a ‘4th generation’ HIV blood test.
· have a test for other STIs.
· have a blood test to check your kidney function.
Every 12 months
· have a hepatitis C test (may need to be done more frequently).
How to take PrEP
For PrEP to be most effective, the medicine needs to be at protective levels at the time that HIV exposure may happen. As the body takes a while to absorb medicines, this means PrEP needs to be taken both before sex and for several days afterwards.
There are two different ways you can take PrEP, depending on your circumstances and how often you have sex:
1. Daily PrEP (taking PrEP every day)
2. Event based dosing (taking PrEP around the time of sex)
1. Daily PrEP: for anal and vaginal sex
Taking PrEP every day will make sure that there are protective drug levels in vaginal and anal tissue, 24 hours a day, 7 days a week.
This means you do not have to plan when to have sex. For people who routinely have sex at least once a week, daily PrEP is likely to be a better dosing option.
You should try and take PrEP at the same time every day.
If you miss a dose, don’t stop PrEP, just continue taking it once you remember.
PrEP and anal sex
When you start taking PrEP, you need to take two tablets of PrEP between 2 and 24 hours before anal sex to make sure that the drug levels are high enough to be protective.
Continue taking one tablet of PrEP per day, every day.
What if I miss a dose?
Daily PrEP allows some flexibility for anal sex. Once you are established on daily PrEP, if you occasionally miss one or 2 doses, protection will still be very high.
For anal sex, you must at the very least have taken PrEP for 4 days a week to have good protection. If you miss more doses than this, you are not going to be protected against HIV if you are having condomless sex. If this happens you should make an appointment to see your healthcare provider.
If you have missed more than 3 doses of PrEP in the week and had condomless sex, you may need PEP (post exposure prophylaxis) and should discuss with your healthcare provider immediately.
If you are missing doses regularly, please discuss this with your healthcare provider and they will advise you on how to proceed.
PrEP for vaginal/frontal sex
For vaginal/frontal sex, you need to take daily PrEP. Event based dosing is NOT suitable. You need to take PrEP every day because PrEP does not get into the vaginal tissues as quickly as it gets into rectal tissues.
You also need to take PrEP every day for 7 days before having condomless sex, to reach protective drug levels.
What if I miss a dose?
There is less flexibility around missing doses for vaginal/frontal sex so it is important to establish a routine for taking the medication.
For vaginal/frontal sex, you must at the very least have taken PrEP for 6 days a week to have good protection. If you miss more than one dose a week, you are not going to be protected against HIV if you are having condomless sex.
If you have missed more than 1 dose of PrEP in the week and had condomless sex, you may need PEP (post exposure prophylaxis) and should discuss with your healthcare provider immediately.
If you are missing doses please discuss this with your healthcare provider.
Other tips on how to take PrEP
Use a pill box – this makes it easy to see whether you have taken or missed a dose.
Set an alarm on your phone or use an app to remind you.
Pick a regular time to take your PrEP and try to stick to this each day. Link it to a routine task like brushing your teeth. It doesn’t have to be the exact same time, but it will help get you into a routine.
If you have a break from PrEP and have condomless sex during this time, it is important to consider PEP and have another HIV test before you re-start PrEP.
2. Event Based Dosing (EBD): only for anal sex
Also known as ‘PrEP 2-1-1’ or ‘PrEP on demand’
Several studies mainly in gay men (including the IPERGAY study) have shown that event based dosing (EBD) is just as effective as daily PrEP for people having anal sex.
Event based dosing (EBD) is a way of using PrEP only when you are likely to have sex.
EBD is an option for people who do not want to take PrEP all of the time, who only occasionally have sex without condoms and who can plan for sex in advance.
EBD is suitable only for anal sex and is NOT suitable for vaginal/frontal sex.
EBD is NOT suitable for transgender women who are using hormone therapy.
EBD is NOT suitable if you have hepatitis B and it is really important to know your hepatitis B status before taking PrEP.
Event based dosing for sex once in a week
1. Take two tablets of PrEP (double dose) between 2 and 24 hours before sex. The before-sex double dose is very important to make sure that there is
enough drug in the body when you have sex.
2. Take a single pill 24 hours after the double dose.
3. Take another single pill the following day, 24 hours later.
Event based dosing for sex several times over a period of time
For example, where you are away for the weekend or on holidays where you may have sex several times over a period of time.
1. Take your double dose (two tablets of PrEP) as usual between 2 and 24 hours before sex.
2. If you are continuing to have sex, take one pill 24 hours after the double dose and continue taking one pill every 24 hours for the days you are
having sex.
3. Continue taking PrEP until you have taken two doses after your last sex. This means taking one dose on each of the two days after your last sex.
It is important to make sure you understand how to take EBD correctly before considering EBD for PrEP. Your healthcare provider can explain this to you and answer any questions you may have.
What if I miss a dose?
It is important not to miss doses if you are taking event based PrEP.
In a situation where you have missed doses of PrEP and haven’t used a condom or had a condom accident, you may need to consider PEP.
If you missed the BEFORE dose completely, still take a double dose as soon as possible AFTER sex, and continue daily, but contact your clinic as soon as possible and within 72 hours. Depending on the risk involved, you may need to go on PEP which will include an additional HIV drug.
Changing how you take PrEP
Your risk of HIV may change over time. You can change how you take PrEP or stop and restart PrEP, as your circumstances change.
Switching between daily and EBD PrEP
PrEP can be individualised to your needs at different times.
If you want to change how you are taking PrEP, discuss this with your healthcare provider. They will help you decide if EBD is an option for you, and make sure you change between daily and event based dosing safely.
If you are using EBD and want to switch to daily dosing, simply start with a double dose, remembering that you need to take the medication at least 2 hours and ideally 24 hours before you are protected and continue taking PrEP daily.
Stopping PrEP
If you decide you want to stop taking PrEP altogether, discuss your decision to stop with your healthcare provider. They can make sure you stop PrEP safely, organise any tests you may need, and provide advice on future prevention of HIV and other STIs.
If your circumstances change in the future, you can restart PrEP.
Remember if you have stopped PrEP and have a sexual exposure risk, you should consider PEP (post exposure prophylaxis). Ideally this should be as soon as possible but no later than 72 hours after the risk.
How to stop PrEP
Anal sex
If you’ve been taking PrEP to prevent HIV through anal sex, continue taking it for 48 hours after the last risk for HIV. This means taking 2 doses final of PrEP: one dose the day after and one dose two days after your last risk. During this time, take PrEP at your regular time.
Vaginal/frontal sex
If you’ve been taking PrEP to prevent HIV through vaginal/frontal sex, continue taking it for 7 days after the last risk for HIV. During this time, take the PrEP at your regular time.
Injecting/slamming drugs
If you are also injecting drugs or slamming chems, you should continue taking PrEP for 7 days after the last risk for HIV. During this time, take the PrEP at your regular time.
Other considerations
Contraception
It is safe to use PrEP with most hormonal contraception (ring, patch, the pill, or an implant). PrEP will not affect your contraception. And the contraception will not affect PrEP.
PrEP in Pregnancy
While there is limited information available on the use of PrEP in pregnancy, no PrEP-related pregnancy complications have been identified.
Becoming HIV positive during pregnancy is associated with an increased risk of transmission of HIV to the baby. Therefore it may be appropriate to use PrEP in pregnancy. If you are taking PrEP and could become pregnant it is important to discuss this with your healthcare provider to help you make an informed decision about what is best for you.
Support services and resources
HSE HIV, Sexual Health, Drugs & Alcohol Helpline
The HSE helpline is a free and confidential service that provides support, information, guidance and referral on anything to do with HIV, sexual health, substance use and alcohol. Call freephone 1800 459 459 Monday to Friday between 9:30 am and 5:30 pm or email helpline@hse.ie.
Sexualwellbeing.ie
The HSE website provides more information on HIV, STIs and sexual health.
HIV post-exposure prophylaxis (PEP)
All PrEP Services are required to either have PEP or have an established referral pathway to a service that has PEP, should you need to access it urgently.
In the case of an emergency, the list of locations where PEP is available in Ireland is available here.
Drugs.ie
For more information on chemsex and support services, click here.
Man2Man.ie
Information and support for gay, bisexual and other men who have sex with men (MSM)
The man2man.ie website provides more information on the following support services: