HIV treatment

Descovy

Detailed information
Keith Alcorn
Estimated reading time 3 minutes

Descovy (tenofovir alafenamide/emtricitabine) is a fixed-dose tablet combining 200mg of emtricitabine and either 25mg or 10mg of tenofovir alafenamide. It is manufactured by Gilead Sciences.

Emtricitabine is a nucleoside reverse transcriptase inhibitor (NRTI) and tenofovir alafenamide is a nucleotide reverse transcriptase inhibitor (NtRTI). These drugs reduce the amount of HIV in the body.

It is licensed for use in adults and adolescents aged 12 years and older with body weight at least 35 kg. Descovy was first approved for use in combination with another antiretroviral agent in April 2016 in the United States and European Union.

Descovy was also approved for use as pre-exposure prophylaxis for the prevention of HIV infection in the United States in October 2019.

Effectiveness

Descovy was approved based on trials in which tenofovir alafenamide (TAF) and emtricitabine were compared to tenofovir disoproxil fumarate (TDF) and emtricitabine, in combination with elvitegravir and cobicistat. All studies showed that a regimen containing TAF was equivalent to a regimen containing TDF. See tenofovir alafenamide for further details.

Taking it

The standard dose of Descovy is one pale blue tablet once a day, with or without food, in combination with at least one other anti-HIV drug.

The fixed-dose tablet containing 10mg of TAF is recommended for use when Descovy is used in combination with the protease inhibitors atazanavir, darunavir or lopinavir, boosted by either ritonavir or cobicistat. The tablet containing 25mg of TAF is recommended with other antiretrovirals.

Side effects

Glossary

antiretroviral (ARV)

A substance that acts against retroviruses such as HIV. There are several classes of antiretrovirals, which are defined by what step of viral replication they target: nucleoside reverse transcriptase inhibitors; non-nucleoside reverse transcriptase inhibitors; protease inhibitors; entry inhibitors; integrase (strand transfer) inhibitors.

trial

A clinical trial is a research study that evaluates a treatment or intervention with human volunteers, in order to answer specific questions about its safety, efficacy and medical effects.

nucleotide reverse transcriptase inhibitor

Family of antiretrovirals which includes tenofovir disoproxil and tenofovir alafenamide. It may be abbreviated to NtRTI or NRTI. It is often said that nucleotide reverse transcriptase inhibitors work in a similar way to nucleoside reverse transcriptase inhibitors, but approach from a different angle.

reverse transcriptase

A retroviral enzyme which converts genetic material from RNA into DNA, an essential step in the lifecycle of HIV. Several classes of anti-HIV drugs interfere with this stage of HIV’s life cycle: nucleoside reverse transcriptase inhibitors and nucleotide reverse transcriptase inhibitors (NRTIs) and non-nucleoside reverse transcriptase inhibitors (NNRTIs). 

resistance

A drug-resistant HIV strain is one which is less susceptible to the effects of one or more anti-HIV drugs because of an accumulation of HIV mutations in its genotype. Resistance can be the result of a poor adherence to treatment or of transmission of an already resistant virus.

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.

People with HIV may gain weight after starting antiretroviral treatment. Clinical trials of new HIV drugs introduced since 2003 show that people taking TAF are at higher risk of substantial weight gain than people taking other antiretroviral drugs.

See tenofovir alafenamide for further information about the impact of TAF on kidney function and bone mineral density.

Drug interactions

Descovy should not be used at the same time as tenofovir alafenamide, tenofovir disoproxil fumarate, emtricitabine, lamivudine or adefovir dipivoxil.

Use of the following drugs should be avoided when taking Descovy:

  • Antimycobacterials: Rifampicin, rifabutin, rifapentine
  • Anticonvulsants: Carbemazapine, oxcarbazepine, phenobarbital or phenytoin
  • Herbal medicine: St John’s wort.

The fixed-dose tablet containing 10mg of TAF is recommended for use when Descovy is used in combination with the anti-fungals itraconazole or ketoconazole.

Resistance

See tenofovir disoproxil fumarate – detailed information for further details.

Pregnancy

The British HIV Association recommends that TAF should be used after the first 12 weeks of pregnancy owing to a lack of information about its effects on foetal development during the first trimester. See tenofovir alafenamide for further details.

Children

Descovy is approved for use in children and adolescents aged 12 years and older with body weight at least 35 kg.

Further information

For more information on Descovy’s component drugs, including drug interactions, side effects and resistance, see emtricitabine (Emtriva) and tenofovir alafenamide.

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