PrEP (Pre-Exposure Prophylaxis)

PrEP works by stopping the virus from making copies of itself and getting into other cells in the body.

The tablet includes two active ingredients called emtricitabine and tenofovir disoproxil, which are part of a group of medicines called antiretrovirals that are used to treat HIV infections. We prescribe unbranded (generic) emtricitabine and tenofovir disoproxil medication for PrEP. Truvada is the branded version of this that is also sometimes used.

Before you start PrEP

Yes. If you are not already taking PrEP, you will need to make sure you are HIV negative before you start. Also, you will need to be hepatitis B and C negative and have normal kidney function. This is because if you do not get tested and start taking PrEP, then find out you are HIV positive, it can make it more difficult to find treatments that work to treat the infection. You will need to have these tests in the 4 weeks before starting PrEP. If you have not already had these, you can arrange these tests with us.

We offer two Introduction test kits you can take before you start using PrEP. The test you need will depend on whether you have to check your hepatitis status.

• Advanced PrEP test*: This tests for HIV, hepatitis B and C, and kidney function. All these tests are needed if you are starting to use PrEP.
• Basic PrEP test: This tests for HIV and kidney function only. You can use this if you are starting PrEP and have already tested for hepatitis B and C recently, or have been vaccinated.

We can also offer a standalone kidney function test if you know both your HIV and hepatitis status already.

While taking PrEP

If you are already taking PrEP, you will need to have regular tests while taking it. You need to have a HIV test every 3 months, and a kidney test at least every 12 months. It is also recommended that you have an STI screen every 3 months.

We offer two Continuation test kits that you can use while using PrEP. The test you need will depend on what stage you are at and what you need to check.

• 3 month Continuation PrEP test: This tests for HIV and kidney function only.
• Annual Continuation PrEP test*: This tests for HIV, hepatitis B and C, and kidney function. We recommend using this once a year while using PrEP.

Should you test positive for hepatitis, we will advise you to see your GP who will refer you to a liver specialist. If your tests indicate abnormal kidney function, you will be asked to repeat the test to check if it normalises.

*Important: You should wait 8 weeks after a hepatitis B vaccination before taking a test to check your hepatitis B status. Taking a test before 8 weeks have passed may give a false positive result. This applies to the Advanced Introduction and Annual Continuation PrEP tests above.

In clinical trials, PrEP has been shown to work when taken:

• regularly (where you take one tablet every day)
• on demand (where you take it only when needed)

We recommend daily PrEP as this is simple and effective for all type of sex (anal, vaginal, or frontal). With daily PrEP, you take one tablet every day. When you first start taking it, it can take 4 days for men to become protected, but longer if you have a vagina or cervix, in this case it’s 7 days. It’s best to take it around the same time every day, and it can be taken with or without food.

‘On demand’ or ‘event based’ dosing should only be used for anal sex, and not frontal or vaginal sex.

When taking it as required you should take:

• 2 tablets, 2 to 24 hours before sex
• 1 tablet 24 hours after sex
• 1 tablet 48 hours after sex

You can message our doctors through your patient account if you have any questions about how to take PrEP.

PrEP is not available over the counter and can only be prescribed by a doctor. PrEP is available on the NHS from sexual health clinics, or you can use our online service to get doctor approved and prescribed treatment, delivered directly to your door.

Although PrEP is generally safe to take, you may get side effects while taking this medicine.

Some common side effects of PrEP include:

• nausea (feeling sick)
• headaches
• diarrhoea
• feeling tired
• stomach pain
• itchy skin

Some less common side effects of PrEP include:

• yellowing of the eyes or skin
• change of colour in stool or urine
• fast or abnormal heartbeat
• shortness of breath

If you get any side effects while taking PrEP, they should normally get better after a couple of weeks. Should side effects remain or you are struggling to deal with them, contact our doctors or your GP. If you get uncommon side effects and are worried, you may wish to visit A&E or get urgent medical help.

PrEP is suitable for people who are HIV negative and who are at a higher risk of getting HIV.

You might be at a higher risk of getting HIV if you are:

• a man who has sex with other men
• a woman who has sex with bisexual people
• a transgender person who has sex with men
• a sex worker
• injecting drugs using syringes or needles, and share those with others
• having sex with somebody who is from a country with high rates of HIV

There may be other reasons that you are at a higher risk of getting HIV. If you think you might be at a higher risk but are not sure, you can message one of our doctors, or speak to your GP or local sexual health clinic.

While PrEP is highly effective at preventing HIV, there are several reasons why it may not be suitable for you. If you are not at a high risk of getting HIV, you do not need to use PrEP. You should not take PrEP if you have tested positive for HIV or show symptoms of HIV infection.

PrEP may not be suitable if you:

• have kidney disease
• have liver disease
• are allergic to the active ingredients, emtricitabine or tenofovir disoproxil
• are pregnant, breastfeeding or trying to have a baby
• have certain health conditions
• are taking certain medications

Our doctors will let you know if it is safe for you to use PrEP from your medical history.

Before we can prescribe PrEP to you, we will ask you about any medicines you are currently taking, or if you have stopped taking medication recently. This is because certain medicines may lower the protection PrEP provides for HIV.

These include:

• some painkillers
• some antibiotics
• medications for treating hepatitis C
• drugs for treating viral or fungal infections
• cancer medication

PrEP is unlikely to interact with alcohol or recreational drugs, but you should drink in moderation while taking PrEP to ensure your liver is healthy.

Even though PrEP is very effective at preventing HIV, it will not protect you from other STIs like herpes, gonorrhoea, or chlamydia. It’s important you attend regular STI screenings every three months if you are using PrEP. If you are pregnant or breastfeeding and are at a high risk of getting HIV, it is always best to speak to your doctor first before taking PrEP.