Descovy is a medication used to treat HIV. It is a combination of two antiretroviral drugs called emtricitabine and tenofovir alafenamide. These are combined in one pill, taken once a day along with another antiretroviral drug.

There are two different forms of Descovy. One form includes 10mg of tenofovir alafenamide and the other has 25mg. Which one you are prescribed will depend on the other antiretroviral drug in your treatment combination.

One form of Descovy combines 200mg emtricitabine and 10mg of tenofovir alafenamide in a grey, rectangular, film-coated tablet. The tablet has ‘210’ on one side and ‘GSI’ on the other side.

The other combines 200mg emtricitabine and 25mg of tenofovir alafenamide in a blue, rectangular, film-coated tablet. The tablet has ‘225’ on one side and ‘GSI’ on the other side.

Descovy combines two drugs in one pill. Emtricitabine and tenofovir alafenamide are from a class of drugs known as NRTIs. (Emtricitabine is a nucleoside reverse transcriptase inhibitor and tenofovir alafenamide is a nucleotide reverse transcriptase inhibitor.)

Your doctor will prescribe Descovy as part of your HIV treatment, along with an antiretroviral from another class of drugs. It is important to take all the drugs as prescribed, every day.

If you take Descovy with an antiretroviral from the protease inhibitor class (atazanavir, darunavir or lopinavir) and a booster drug (ritonavir or cobicistat), then you will be prescribed the form of Descovy that includes 10mg of tenofovir alafenamide.

If you take Descovy with antiretrovirals from other classes (dolutegravir, efavirenz, maraviroc, nevirapine, rilpivirine or raltegravir), then you will be prescribed the form of Descovy with 25mg of tenofovir alafenamide.

Each drug class works against HIV in a different way.

The aim of HIV treatment is to reduce the level of HIV in your body (viral load). Ideally, your viral load should become so low that it is undetectable – usually less than 50 copies of virus per ml of blood. Taking HIV treatment and having an undetectable viral load protects your immune system and stops HIV being passed on to someone else during sex.

You should take Descovy once a day with or without food.

HIV treatment works best if you take it every day. If you forget to take a dose of Descovy, take it as soon as you remember. If it’s nearly time to take your next dose (within the next six hours) then don’t take a double dose, just skip the dose you’ve forgotten and carry on.

If you regularly forget to take your treatment, or you aren’t taking it for another reason, it’s important to talk to your doctor about this.

All drugs have possible side-effects. It’s a good idea to talk to your doctor about possible side-effects before you start taking a drug. If you experience something that might be a side-effect, talk to your doctor about what can be done. A full list of side-effects, including less common side-effects, should be included in the leaflet that comes in the packaging with Descovy.

We generally divide side-effects into two types:

Common – a side-effect that occurs in at least one in a hundred people (more than 1%) who take this drug.

Rare – a side-effect that occurs in fewer than one in a hundred people (less than 1%) who take this drug.

The most common side-effect of Descovy is nausea. Other common side-effects include abnormal dreams, headache, dizziness, diarrhoea, vomiting, stomach pain, flatulence, rash and fatigue.

It’s important that your doctor and pharmacist know about any other drugs you are taking. That includes medicine prescribed by another doctor, drugs you have bought from a high-street chemist, herbal and alternative treatments, and recreational drugs.

Some medicines should not be taken together because if they are this can cause serious side-effects, or it can stop one or both of the drugs from working. Other drug interactions are less dangerous but still need to be taken seriously. If levels of one drug are affected, you may need to change the dose you take.

A list of drugs, known to have interactions with Descovy, should be included in the leaflet that comes in the packaging with Descovy. Tell your doctor if you are taking any of these drugs, and other drugs that are not on the list.

You should not take Descovy with any of the following drugs, used to treat hepatitis B:

• tenofovir disoproxil fumarate
• lamivudine
• adefovir dipivoxil

There are other interactions, including with common drugs such as some antibiotics, antivirals used to treat hepatitis C, anticonvulsants used to treat epilepsy and the herbal remedy St John’s wort, so it is very important that you tell your doctor about other drugs you are taking.

If you are considering having a baby, or think you might be pregnant, talk to your doctor as soon as possible about which combination of anti-HIV medications would be right for you. It is important to take antiretroviral treatment during pregnancy to prevent passing HIV from mother to baby.

Descovy is not usually used by women who are pregnant or want to get pregnant as it has not been studied in women who are pregnant. For this reason, the British HIV Association (BHIVA) does not recommend its use in pregnancy.

Women living with HIV are advised not to breastfeed, as HIV can be passed on in breast milk. However, some women do choose to breastfeed. Descovy should not be used during breastfeeding as at least one of the drugs it contains passes into breast milk.

Descovy can be taken by children aged 12 years and over, weighing 35kg or more.

If you have any concerns about your treatment or other aspects of your health, it’s important to talk to your doctor about them.

For example, if you have a symptom or side-effect or if you are having problems taking your treatment every day, it’s important that your doctor knows about this. If you are taking any other medication or recreational drugs, or if you have another medical condition, this is also important for your doctor to know about.

There are other things which are important to your health and HIV care, and which you and your doctor may take into account when making decisions about your treatment. For example, if you are considering having a baby, or want to start taking contraception.

Building a relationship with a doctor may take time. You may feel very comfortable talking to your doctor, but some people find it more difficult, particularly when talking about sex, mental health, or symptoms they find embarrassing. It’s also easy to forget things you wanted to talk about.

Preparing for an appointment can be very helpful. Take some time to think about what you are going to say. You might find it helpful to talk to someone else first, or to make some notes and bring them to your appointment. Our online tool Talking points may help you to prepare for your next appointment – visit www.aidsmap.com/talking-points