Pre-exposure prophylaxis

Pre-exposure prophylaxis (PrEP) refers to the use of anti-retroviral therapy (ART) to prevent the new acquisition of HIV.

Prevention of new infections is fundamental to the management of HIV. There have been a number of studies which show, with excellent adherence, PrEP offers marked reduction in the risk of contracting the virus.

There are a number of indictions for PrEP which typically takes the form of Tenofovir Disoproxil / Emtricitabine (TD-FTC). It can be given in two ways depending on the individuals requirements and risks:

• Daily tablet
• On demand (e.g. two tables 2-24 hours prior to sex, and one tablet daily for two days after)

This note is based on the 2018 BHIVA guidelines, but it should be noted this is a rapidly developing area with frequent changes to practice.

Each case should be reviewed based on its individual merits in individuals at increased risk of HIV exposure.

Men who have sex with men

PrEP should be offered, either on-demand or as daily oral TD-FTC, to:

• HIV-negative MSM who are identified as being at elevated risk of HIV acquisition through condomless anal sex in the previous 6 months and ongoing condomless anal sex.
• HIV-negative MSM having condomless anal sex with partners who are HIV positive, unless the partner has been on ART for at least 6 months and their plasma viral load is <200 copies/mL.

Heterosexual populations

PrEP should be offered in the form of oral daily TD-FTC to ‘HIV-negative heterosexual men and women having condomless sex with partners who are HIV positive, unless the partner has been on ART for at least 6 months and their plasma viral load is <200 copies/mL.’

PrEP should be considered on a case-by-case basis for ‘heterosexual men and women with current factors that may put them at increased risk of HIV acquisition.’

Trans people

BHIVA recommend daily oral TD-FTC is offered to ‘HIV-negative trans women who are identified as being at elevated risk of HIV acquisition through condomless anal sex in the previous 6 months and ongoing condomless sex.’

They also recommend daily TD-FTC is offered to ‘HIV-negative trans women and trans men having condomless sex with partners who are HIV positive, unless the partner has been on ART for at least 6 months and their plasma viral load is <200 copies/mL.’

People who inject drugs

BHIVA recommend techniques such as needle exchanges and opiate substitution programmes are used. PrEP should be considered on a case-by-case basis.

All patients require a HIV test at baseline.

A careful history and examination should be completed. For patients with a high-risk exposure in the last 72 hours should be considered for Post Exposure Prophylaxis after Sexual Exposure to HIV (PEPSE). Following appropriate PEPSE and follow-up testing, PrEP can be considered. It can be complex if someone has had a recent high-risk exposure (outside the window for PEPSE), a HIV viral load may be sent alongside the HIV test due to the risk of a false-negative.

Patients should be counselled on their ongoing risk, the medication and its side effects as well as offered any psychological support they may need. Patients must understand adherence is key to the efficacy of PrEP, and where relevant additional support should be provided. They must also understand they are at ongoing risk of other STIs. In addition they should be educated on the symptoms of seroconversion and advised to present for HIV testing should they occur.

Services vary depending on location but behavioural and psychosexual support should be offered where possible. The use of drugs as a key part of someones sex life is referred to as ‘chemsex’. There are services that can offer specialised support for those engaging in chemsex where it is requested.

Prior to commencement patients should have their urinalysis and renal function reviewed, an STI and viral hepatitis screen. Renal impairment is a relative contra-indication and specialist advise should be sought.

Patients on PrEP need regular follow-up.

Patients should be reviewed regularly and encouraged to report any side-effects. Each visit is an opportunity to check their well-being and address any new or existing issues.

In women of child bearing age a pregnancy test should be considered, as should review of bone mineral density where relevant. Routine monitoring should include:

• HIV test (3 monthly)
• STI screening (3 monthly chlamydia, gonorrhoea and syphilis +/- hepatitis C)
• Renal function (based on age and current eGFR)