PEP
Post exposure prophylaxis (PEP) is anti-HIV medication that is prescribed to a HIV negative person, after a potential exposure to HIV, to protect them from acquiring HIV (becoming HIV positive). It should be started within 72 hours of the exposure, the earlier the better. It won’t usually be prescribed after 72 hours. PEP needs to be taken daily for 28 days.
Evidence suggests PEP reduces the chances of HIV infection by approximately 80%. It is not a cure for HIV and it doesn’t work in all cases in preventing HIV transmission: some strains of HIV aren't affected by the medicine. Also if you don’t take it correctly or start it too late it may fail to protect you.
PEP can be provided in A and E departments or sexual health services.
It can have some side effects, such as tiredness, sickness, diarrhoea, and headache.
PEP may be considered or recommended in the following circumstances
1. If your partner is HIV positive AND
- you had condomless anal sex with them OR
- you had condomless vaginal sex with them OR
- you shared their equipment for injecting drugs
2. Your partner’s HIV status is unknown or unclear, but they belong to a group where the rates of HIV are high. These groups include gay or bisexual men; those who have migrated to the UK from countries with high HIV prevalence (ie >1%), eg Sub Saharan Africa; people who inject drugs and are from high risk countries such as Eastern Europe and Central Asia AND
- you had unprotected anal sex with them OR
- you had unprotected vaginal sex with them OR
- you shared their equipment for injecting drugs
If you have an HIV positive partner who has been taking HIV treatment correctly and consistently, for more than 6 months, and who has had an undetectable viral load during this time, you won’t need PEP. In this situation the risk of acquiring HIV (if they are your only partner) is zero.
The following risks do not usually warrant PEP: human bites, semen splash to the eye, oral sex.
But… there are many factors that are involved in deciding whether you require PEP after an exposure or not so if in doubt attend A and E or a sexual health clinic as soon as possible.
Before you are given PEP you need to have a HIV test. This is because if you are already HIV positive we need to do further tests to rule out drug resistance, before starting treatment on you.
You will need to have further HIV tests after completing the PEP course to confirm you have not become HIV positive. It is also recommended you have testing for other blood borne infections like hepatitis B and hepatitis C as well as a full sexual transmitted infection screen (chlamydia, syphilis and gonorrhoea).
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PrEP
Pre-exposure prophylaxis (PrEP) is a course of HIV drugs taken by an HIV negative person to lower their chance of acquiring HIV. There are different ways you can take PrEP. For example, you can take it every day for continuous protection or 'event based' dosing when you take it when you can predict you are going to have sex.
PrEP is extremely effective and available on the NHS. For people who take it properly, PrEP provides almost 100% protection against HIV. Before starting PrEP and whilst taking it you need to have regular HIV testing, tests for other STIs, and checks on your kidney function.
Some scenarios where you might consider starting on PrEP are below.
- You have condomless sex with an HIV positive partner/s who is not taking HIV treatment or who has a detectable viral load.
- You have used PEP (post-exposure prophylaxis) in the last few months.
- You engage in chemsex, sex work, group sex or sex parties.
- You share drug injecting equipment.
- You are a cis or transgender gay or bisexual man or a transgender woman and
- have had condomless anal sex in the past six months and think you will do so again.
- have recently been diagnosed with Hepatitis C or syphilis
- have recently had a rectal STI (gonorrhoea, LGV or chlamydia in your anus)
- You don't meet the above descriptions, but you feel at high risk, or you've been clinically assessed as being at high risk of acquiring HIV, whatever your gender or sexuality.