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Post exposure prophylaxis after sexual exposure – PEPSE

What is PEPSE?

PEPSE stands for post exposure prophylaxis following sexual exposure. It is a short course of HIV treatment, given to people who may have been exposed to HIV, in order to reduce the risk of them becoming HIV positive.

The most common reason for giving PEPSE is when someone has had unprotected vaginal or anal sex (without a condom or when the condom breaks or splits) with someone who is HIV positive or is thought to be at high risk of having HIV infection. 

PEPSE needs to be taken as soon as possible after the unprotected sex happens and no later than 72 hours after it happens.  It is a 28-day course of medications that need to be taken every day and have activity against the HIV virus. The medicine must be taken regularly at the same time everyday and the course completed. 

Does PEPSE work?

Research suggests that PEPSE makes infection with HIV less likely.  The efficacy of PEPSE depends on adherence to the medication. With missed pills or taking the pills not at the right time, the efficacy of PEPSE drops.  It can also fail because some anti-HIV drugs don’t work against some strains of the HIV virus.

What should I do if I think I need PEPSE?

PEPSE needs to be taken as soon as possible and not later than 72 hours after the unprotected sex happened. To access PEPSE you will need to see a Genito-Urinary Specialist at a GU clinic or else the nearest accident and emergency department (A+E).  The doctor who sees you, will decide about whether you need to take PEPSE or not. If PEPSE is recommended by the doctor you will need an HIV test to make sure you are not already positive. You will then have blood tests to check liver and kidney function. If you are given PEPSE you will need regular check-ups and an HIV test needs to be repeated 4 weeks after finishing PEPSE to completely rule out HIV infection. 

Is PEPSE provided free of charge?

At the moment PEPSE is not being provided free of charge and needs to be bought.  You will need a prescription by a GU Specialist and the course for 1-month costs over 500 euros. 

Are there any side effects?

PEPSE can cause side effects and these tend to be worse when treatment is first started. The most common side-effects are headaches, nausea, bloating, diarrhoea and tiredness although these usually wear off after a week. If there is troublesome persistent nausea or diarrhoea these can be treated with other medications to make you feel better. 

Things to remember about PEPSE 

  1. PEPSE might stop someone getting infected with HIV.

  2. Its not guaranteed to work.

  3. It must be started as soon as possible after unsafe sex or a condom breaking, and within 72 hours.

  4. At the moment PEPSE needs to be bought as it is not provided free of charge.

  5. It means taking medications for 4 weeks. 

  6. Side effects are common but can be managed with other medicines. 

  7. Not everyone wanting PEPSE will get it. The doctors will decide who needs it and it will be prescribed only when indicated. 

  8. PEPSE only protects against HIV but not against any other sexually transmitted infections like chlamydia, gonorrhoea or syphilis.

PEPSE is not a cure for HIV and is not guaranteed to prevent HIV from taking hold once the virus has entered the body. Using condoms during sex remains the most efficient way of staying safe from HIV. 

This is part of a series of monthly posts by:

Dr Donia Gamoudi.

Genitourinary (GU) Medicine doctor 


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