HIV post exposure prophylaxis
Read our guide below about how his medication can help reduce the risk of HIV infection.
You can also download a PDF version of this patient information by following the link on the right.
What is post exposure prophylaxis (PEP)?
The doctor/nurse has assessed that you have a risk of catching HIV from your recent exposure. You can reduce this risk greatly by taking a course of PEP for 30 days.
Starting PEP as early as possible, taking every dose as prescribed and completing the 30-day course provides the best protection against infection.
- take the first dose of medication immediately
- attend the follow up appointment as advised by the person who prescribed your PEP.
What does the medication include?
It consists of a combination of 2 tablets containing 3 active drugs. All 3 are antiviral drugs that are effective against the HIV virus.
Used together, there is evidence that they can reduce the risk of developing HIV infection following exposure.
The names of your medicines are:
- Tenofovir/Emtricitabine co-formulation – tablet containing 200mg of emtricitabine and 245mg of tenofovir disoproxil
- Raltegravir – pink 600mg tablets
When should I take medications?
You should take the first dose of Tenofovir/Emtricitabine (1 tablet) and Raltegravir (2 tablets) as soon as you get them.
You should swallow the tablets whole. Crushing, chewing or splitting them may affect the levels of the medicine in your body.
Taking doses with food may help to prevent nausea (feeling sick) which can occur when you first start taking the medicine.
After the first dose, continue to take the medications as follows:
- Tenofovir/Emtricitabine – 1 tablet to be taken once each day (every 24 hours)
- Raltegravir – 2 tablets to be taken once a day (every 24 hours)
What if I miss a dose?
It’s very important that you do not miss any doses and take the medicines regularly. This will ensure a constant level of medicines in your blood.
If you do miss a dose, take it as soon as you remember and then take your next dose at its regular time. If it’s almost time for your next dose anyway, do not take a double dose. Wait and take the next dose at the regular time. If you have not taken any of your treatment for 48 hours, tell your doctor as soon as possible.
If you have taken your first dose at an unusual time, you can adjust the doses gradually (1 to 2 hours each time) until they’re at a standard time, for example 9am.
Are there any side effects?
PEP medicines can cause side effects such as sickness, headache, and tiredness. If you experience side effects and feel you can no longer take the medicines, please get medical advice as soon as possible.
Like all medicines, not everybody will experience side effects. If you do develop any side effects, they’re most likely to be mild and short term.
Tell your clinic immediately if you develop:
- a rash
- flu-like illness, for example a sore throat, fever, muscle pains, enlarged glands.
It’s important to make sure you’re symptoms are not an allergic reaction or signs of HIV infection.
What should I do if I have a side effect?
Some people will have side effects and others will have none at all. Side effects can also improve over time.
The medication may cause you to feel sick or be sick. If this happens then it may affect how well your treatment works, especially if you’re sick soon after taking a dose. You must get medical advice for these side effects as soon as possible.
If you need advice, contact:
- your GP
- walk-in centre
- Occupational Health service (if you have been exposed at work)
- bSHaW Sexual Health Service (if you have been exposed through sex).
You’ll find contact details at the bottom of this page.
Outside of opening hours, contact your local 24-hour GP service. You should find details on the answer phone message of your local GP.
If you have any other side effects that concern you, contact your follow-up clinic, GP or NHS 111. If you think you may need urgent medical help, go to your nearest A&E.
Do not stop taking the medicines unless advised to by your doctor.
I’m taking other medications, can I still take PEP?
Some medications can stop you from absorbing Raltegravir properly. These include:
- calcium, iron, magnesium and aluminium (found in indigestion remedies)
- vitamins and mineral tablets
- herbal remedies
We do not recommend you take these for the duration you are taking PEP.
The PEP medicines may interact with other medicines, including those you have bought yourself.
If you’re on any medications, prescribed or non-prescribed, please let medical staff know. Do not start any new medication without talking to your doctor first. You may drink alcohol while taking these medicines within recommended limits.
You should tell anyone recommending a new treatment for you that you’re taking PEP medicines. Always check with a doctor or pharmacist before starting any new medicines during the 30 days of treatment.
Will I have a follow-up appointment?
Yes. PEP does not reduce the risk of HIV infection to zero. This is one of the reasons you’ll have follow up appointments during and after the PEP course. If you have started on PEP in A&E following a sexual exposure, please contact bSHaW the next working day for a follow up appointment.
Important advice about your medication
- have unprotected sex or donate blood while you’re being treated and until your final HIV test confirms that you’re not infected
- use recreational or ‘street’ drugs whilst taking PEP
- take more than the recommended dose of your PEP
- give your medicines to others
Keep your medicines in a cool, dark, dry place, out of the reach of children.
Reducing associated healthcare infections
Find out how you can help to reduce healthcare associated infections when visiting hospital
About our patient information pages and leaflets
This patient advice is intended as general information only. We aim to make the information as up to date and accurate as possible, but please note that it is subject to change.
Always check specific advice on any concerns you may have with your doctor.
bSHaW Sexual Health Service
0300 300 2880
Walk in service available on most days.
Opening times at Aylesbury clinic
Opening times at Wycombe SHAW clinic
For staff members of Buckinghamshire Healthcare NHS Trust
Occupational Health, 8am to 4pm
For non BHT staff members, contact your own occupational health service.