PEP (Post-exposure prophylaxis)

If you think that you have been exposed to HIV from having a one off incident of unprotected sex or a condom breaking then there is a course of medication that you can take which may prevent you becoming HIV positive.

Post-exposure Prophylaxis (PEP) is a four week course of anti HIV medication that must be taken within 72 hours of possible exposure. The word PEPSE is sometimes used – it stands for PEP after Sexual Exposure. The course of treatment may have side effects such as nausea, diarrhoea and feeling tired or unwell.

It should not be thought of as a ‘morning after pill’ for HIV.

When would PEP be given?

PEP is available for 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 under which circumstances. The best place to access PEP from is A&E departments. If you think you have been exposed to HIV then you should go to A&E as soon as possible. Your GP cannot issue PEP.

PEP is not guaranteed to work in 100% of cases but the sooner you can get access to the treatment after the possible exposure, the more likely it is to work. PEP needs to be taken as soon after exposure as possible. This is preferably within hours rather than days. Most guidelines have a cut off for PEP of 48 hours after exposure.

Even though in the UK you can get PEP for up to 72 hours it is much less likely to work when it is used this late. The longer the delay the less the chance that PEP will work. You can only access PEP up to a maximum of 72 hours following possible exposure and is not likely to be effective after this time.

What will happen if I ask for PEP?

PEP involves powerful and expensive drugs. 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 or anal?).
  • If the other person definitely had HIV, what was their ‘viral load’ (if this is known)? If the person you had sex with is living with HIV, but on treatment and has had an ‘undetectable viral load’ for at least six months, you will not need PEP.
  • If the condom broke (condom failure).
  • If the status of the ‘source’ individual is unknown and there has been unprotected sex if the sex was receptive and the ‘source’ is from an area of high HIV prevalence (you’ve had unprotected sex, bottom not top in an area with high HIV rate)
  • If the unprotected sex was as a result of sexual assault – aggravated sexual intercourse increases risk (more chance of tears etc, increasing routes of transmission) and therefore PEP may be more readily considered

Other factors that may influence if you're given PEP

Where there’s another STI present (the person presenting knows they have one or they have symptoms), whether or not the person presenting has a foreskin/is circumcised may affect the level of risk and therefore whether PEP is considered effective

What will happen if you’re given PEP?

There will be a discussion around sexual risk, the side effects of PEP and how to take them. You will be offered a rapid test with a pre-test discussion. This makes sure that you don’t already have HIV; if you do, taking PEP is not the treatment you need.

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 you miss more than 48 hours of PEP it will be discontinued.

If you're given PEP, there will be:

  • Discussion around risks, side effects and how to take them
  • A rapid HIV test with pre-test discussion
  • Given an appointment at GUM/HIV department asap to see a clinical expert
  • Possible need to continue with further 4 weeks of meds if result is negative
  • You will need to have a HIV test after 12 weeks and PEP completion (HIV can take 12 weeks following infection to show on a test)
  • A discussion on the need to have safer sex/use of condoms and lube, how to disclose HIV status, coping strategies for if you are diagnosed HIV postiive and recommendations for counselling / support services / social support

Help getting PEP

If you have had a recent (within the last 72 hours) potential exposure to HIV but you are nervous about going requesting it from A&E or don't quite know what to ask for, LGBT Foundation and BHA for Equality have prepared a draft statement for you to say to the doctor/nurse to make sure your request is communicated clearly and dealt with appropriatley. This can be downloaded from the link here.