HIV PEP – What You Need to Know


HIV post exposure prophylaxis (PEP) is a course of HIV medication that aims to prevent HIV infection following a recent exposure to HIV, such as condomless sex, sharing needles or pricking yourself with an infected needle.

PEP must be started within 72 hours (3 days and nights) after a possible exposure to HIV, and sooner if possible.

A full course of PEP is for 28 days (4 weeks).

PEP is recommended if, during sex, a condom tears or slips off, or maybe one wasn’t used. You might have been drunk or high and don’t know for sure. Whatever the reason, you or your partner may have been sexually exposed to HIV. PEP if used within 72 hours may prevent the HIV virus from taking hold in your bloodstream. The important thing is to attend an STI/GUM clinic or Emergency Department and talk to a healthcare provider to see if you need to take it. Familiarising yourself with the information below might be helpful for yourself, a sexual partner or a friend in the future.

PEP is available in many STI clinics. If it is not possible to get PEP from your STI clinic within 72 hours, PEP can be accessed in a number of emergency departments.
Click here to view or download a list of locations where PEP is available in Ireland.

What You Need to Know

PEP can stop HIV replicating itself in the body after the virus has entered the body:

  1. PEP is an emergency measure if you have been exposed to HIV.
  2. The earlier PEP is taken the better. If you’ve had a high-risk sexual encounter within the last 72 hours (three days), it’s important to get help straight away (check the list of where to get PEP here). It is vital that this medication is given within 72 hours (three days) of the potential exposure to the virus, otherwise it will not work, so, ‘please don’t leave it until the 72 hours is up or nearly up’.
  3. PEP can only be prescribed by doctors and if certain criteria are met.
  4. Most STI or GUM clinics can provide PEP, as can Emergency Departments (ED) and sexual assault units (for sexual assault only).
  5. PEP is free of charge at all public STI /GUM clinics, however at Emergency Departments and if you have no referral letter, you may have to pay the €100 mandatary attendance fee for Emergency Departments (some Hospitals may charge more if you are a non-EU National).
  6. All public STI/GUM clinics listed at the link are free to attend.

What is PEP?

Post = After

Exposure = a situation where HIV has a chance to get into someone’s blood stream.

Prophylaxis = a treatment to stop an infection happening.

PEP is a combination of anti-viral drugs. It involves a 28-day (4 week) course of tablets that is prescribed to someone who has been exposed to HIV.

To be effective, PEP must begin as soon as possible after the exposure and before 72 hours (3 days) is up. ‘So, the sooner you start after exposure, the better it works’.

You must remember to take the medication every day for the full 4 weeks. If you miss any doses or do not complete the course it greatly affects the chance of PEP working.

How do I get PEP?

PEP is available for free at all public STI/GUM Clinics and Emergency Departments, (the €100 fee might be charged –if you have no referral letter-for attendance at Emergency Departments). PEP is only given to people who meet the national guidelines for its use

These national guidelines help doctors decide who might be offered PEP. Some of the questions asked are;

Do you know your own HIV status?

  • The person you had sex with (and the chances that person had HIV).
  • What kind of sex happened (vaginal, oral or anal?).
  • If the other person definitely had HIV, what was their ‘viral load’ (if this is known)?

Once a doctor has considered your risk, a decision will be made about whether PEP is provided. At the same time, you will have a series of blood tests. This makes sure that you don’t already have HIV, depending on the result, you will continue PEP.

The best place to go for PEP is your nearest STI/GUM clinic, check the list. If you need PEP over the weekend, outside of STI/GUM clinic hours or during a public holiday, the best place to go is the nearest Emergency Department of a hospital. Most are open 24 hours with some community departments open till midnight (see list ‘Where to Get PEP’). PEP is not available from GPs (family doctors) or from pharmacies.

In Emergency Departments and some STI/GUM clinics you will be given a “PEP starter pack”. This means if the doctor decides to prescribe PEP to you after the assessment, you will be given a short course of PEP for four to six days. This is not the full course. If given a PEP starter pack, you will be referred to another clinic for further assessment based on your blood results and for continuation of treatment if recommended.

Sometimes people might face obstacles when asking for PEP. The medical staff or receptionists may not know about it or may give out incorrect information such as ‘PEP is not available to the general public’.

If this happens, ask to speak to the ‘doctor on duty’ who should know about the PEP guidelines. ‘Don’t panic’ check the list for nearby options also see the support section here for helplines that you can call for help and advice.

PEP is still available during current Covid-19 restrictions. If you have had a recent exposure to HIV, it is important to take urgent action. Contact your nearest Hospital Emergency Department where PEP is available or contact your local sexual health clinic. This should be done within 72 hours (3 days) of sexual contact.

How do I take PEP?

In 2017 the combination medication used for HIV PEP is a tablet called Truvada® (which contains Tenofovir and Emtricitabine) and either two tablets called Isentress® (containing Raltegravir) or one table called Tivicay® (containing Dolutegravir). These antiretroviral drugs are commonly used to treat HIV. For PEP to have the best chance of working it must be taken exactly as instructed by a doctor and for 28 days.

When you are prescribed PEP you should receive printed information of; the types of tablets, what to do if you miss a dose, the possible side effects, and what medicines or herbal treatments may affect you. There is an outline for this below;

Skipping doses, or not taking the pills for the full month, makes it likely that PEP will not work – if you miss more than 48 hours (two days) please tell your prescriber as they may advise that PEP be discontinued.

If you forget to take your PEP tablets, follow this procedure;

  1. If you remember within (12 hours for Truveda) or (six hours for Isentress) after you were due to take it, ‘take the missed dose and go back to the usual time for the next one’.
  2. If more than 12 hours or the six hours, after you were due to take the dose, ‘wait and take your dose at the usual time’. ‘Don’t take extra tablets to make up for the missed dose’.

As recreational drugs can have dangerous interactions with HIV medication, it’s advisable not to use them while taking PEP.

Tell the doctor assessing you about any prescribed drugs, recreational drugs, herbal treatments or over-the-counter medicines you’re taking.

If you do get side effects from PEP they are likely to be mild ones experienced in the first few days, such as nausea, headaches, dizziness or tiredness – they should pass after a day or two.

Once you’re finished taking PEP you will be tested for HIV again four weeks after finishing the course.

You may be advised to follow-up for other blood and STI tests three months after this.

Where can I get PEP?