Post exposure prophylaxis

Condoms are the best way of stopping HIV: they can be free (from your doctor or sexual health clinic), are easy to find, have no side effects, only need to be used during sex and don’t require medical help.

But something else can prevent HIV infection, the only thing that can stop a person becoming infected after HIV has entered their body. Its called post exposure prophylaxis, also known as PEP.

What is PEP?

PEP is a month long course of HIV drugs that someone takes very soon after sex which had a risk of HIV transmission.

The drugs are the same ones taken by people with HIV, and for PEP to work they must be taken for four weeks. The sooner PEP is started, the more likely it is to work; within 24 hours is best, but no later than 72 hours (three days). After 72 hours PEP is unlikely to work.

PEP is not a ‘morning after’ pill to stop HIV as it is not taken just once but must be taken every day for 28 days. If someone stops taking it before 28 days there is a possibility that it will not have worked.

Getting PEP

PEP is available free on the NHS but it is only given to people who meet national guidelines about its use. These guidelines help doctors decide who might be offered PEP and in which circumstances.

PEP involves powerful and expensive drugs that have side effects. To make sure it isn’t given to people with no real risk of infection, if you want PEP you will be asked questions about:

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

To help you work out if PEP is appropriate for you or someone you’ve had sex with you can call THT Direct on 0808 802 1221 or  complete this online assessment

The best place to go for PEP is a sexual health (GUM) clinic or a HIV clinic. These are usually open only during the week and only during office hours. If you need PEP over the weekend or during a public holiday the best place to go is the Accident and Emergency (A&E) department of a hospital. A&E departments never close but there is no guarantee that an A&E will agree to give someone PEP. PEP is not usually available from GPs (family doctors).

Once a doctor has considered your risk, a decision will be made about whether PEP is appropriate. If so, you must first have a HIV test. This makes sure that you don’t already have HIV; if you do, taking PEP is not the right treatment you need.

Sometimes people face obstacles when asking for PEP. Medical staff or receptionists may not know about it or give out incorrect information such as ‘PEP is not available to the general public’. If this happens, ask to speak to the ‘on-call HIV doctor’ who will know all about PEP. If you have nearby options, you could go to another hospital. You can call THT Direct on the above number for help and advice.

Taking PEP

For PEP to have the best chance of working it must be taken exactly as instructed by a doctor and for 28 days. Skipping doses or not taking the pills for the full month makes it likely that PEP will not work.

If a dose is missed take the next dose as soon as you remember – don’t take double the dose.

It is common for people taking PEP to get side effects. These will stop once the course of drugs has been completed but for some people they can make sticking with PEP difficult. Headaches, tiredness, feeling sick and diarrhoea are common side effects.

If you are finding the treatment difficult, speak to the clinic that gave it to you; they can give you medication to help with side effects. Because of side effects some people need to take time off work or study while they are on PEP. Also, as recreational drugs can have dangerous interactions with HIV medication, it’s advisable to not use them while taking PEP.

To be sure that no infection has taken place, three months after the course of PEP drugs has been completed a HIV test is carried out. If you decide not to take PEP, a HIV test is recommended anyway, along with a check up for sexually transmitted infections.

When someone is taking PEP they will be advised not to have any further unprotected sex during the 28 days of treatment as this will make it more likely that PEP does not work.

PEP is an emergency measure to be used as a last resort, eg, if a condom breaks or you have a ‘slip up’ from your usual safer sex routine. PEP is a combination of powerful drugs and can be hard to get hold of, so it is no substitute for condoms, but it is important to know about in case one day you or someone you’ve had sex with needs it.

PEP is not guaranteed to always work but has a high success rate. It is free of charge but can only be prescribed by doctors and if certain criteria are met. Sexual health and HIV clinics can provide it, as can Accident & Emergency departments of hospitals. Regular family doctors (GPs) don’t give PEP.

Page content supplied by Copyright 2012 © Terrence Higgins Trust.

Leave a Reply

Your email address will not be published.