Lenacapavir

What is lenacapavir?

Lenacapavir is a medication used to treat HIV, marketed under the brand name Sunlenca. It is taken in combination with other antiretroviral drugs and is suitable for people who have resistance to antiretroviral drugs.

Lenacapavir is a long-acting medication that is given by injection.

How does lenacapavir work?

Lenacapavir is from a class of drugs known as HIV capsid inhibitors. Your doctor will prescribe lenacapavir as part of your HIV treatment, along with other antiretrovirals which will probably be taken as daily tablets. The other drugs you take will be chosen after your HIV has been tested for resistance, from at least one other class of drugs, so that the combination you take will be as effective as possible.

It is important to take all the drugs as prescribed, every day. 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.

How do I take lenacapavir?

Lenacapavir treatment starts with oral dosing to establish stable blood levels. You will take two 300mg tablets on days 1 and 2, then one 300mg tablet on day 8.

On day 15, you will receive two injections of lenacapavir in different places under the skin in your abdomen.

These injections should be repeated every six months (26 weeks) and no more than 28 weeks after the last lenacapavir injection. If the next dose is delayed by more than 28 weeks after the previous injections, dosing should begin again with oral lead-in before injections are resumed.

What are the possible side effects of lenacapavir?

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 lenacapavir.

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.

Common side effects of lenacapavir include:

  • Nausea (feeling sick)
  • Pain at the injection site.

Does lenacapavir interact with other drugs?

You should always tell your doctor and pharmacist about any other drugs or medication you are taking. That includes anything prescribed by another doctor, medicines you have bought from a high-street chemist, herbal and alternative treatments, and recreational or party drugs (‘chems’).

Some medicines or drugs are not safe if taken together – the interaction could cause increased, dangerous levels, or it could 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. This must only be done on the advice of your HIV doctor.

Lenacapavir should not be used with the following medicines:

  • Tadalafil for pulmonary artery hypertension
  • Rifampicin, rifabutin for tuberculosis or mycobacterial infections
  • Carbamazepine, phenytoin, oxcarbazepine, phenobarbital (anticonvulsants)
  • St John’s wort for anxiety or depression.

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

If you are taking lenacapavir, it is particularly important to check with your HIV doctor or pharmacist before taking any of the following medicines:

  • Dihydroergotamine or ergotamine (ergot derivatives)
  • Dexamethasone, hydrocortisone/cortisone (corticosteroids)
  • Lovastatin, simvastatin (statins)
  • Digoxin (antiarrhythmics)
  • Midazolam or triazolam (sedatives)
  • Rivaroxaban, dabigatran, edoxaban (anticoagulants)
  • Sildenafil, tadalafil, vardenafil (drugs used to treat erectile dysfunction).

Lenacapavir will remain in the blood for up to nine months after the last dose and so will continue to influence the levels of the drugs listed in this section for some time after discontinuation.

Can I take lenacapavir in pregnancy?

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.

It is not recommended to take lenacapavir at the time of becoming pregnant or during pregnancy, as not enough is known about its use during pregnancy.

If you become pregnant while taking lenacapavir, see your doctor as soon as possible to review your treatment.

Can children take lenacapavir?

Lenacapavir is not approved for use in children.

Talking to your doctor

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

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.

viral load

Measurement of the amount of virus in a blood sample, reported as number of HIV RNA copies per milliliter of blood plasma. Viral load is an important indicator of HIV progression and of how well treatment is working. 

 

undetectable viral load

A level of viral load that is too low to be picked up by the particular viral load test being used or below an agreed threshold (such as 50 copies/ml or 200 copies/ml). An undetectable viral load is the first goal of antiretroviral therapy.

drug interaction

A risky combination of drugs, when drug A interferes with the functioning of drug B. Blood levels of the drug may be lowered or raised, potentially interfering with effectiveness or making side-effects worse. Also known as a drug-drug interaction.

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.

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.

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. 

For detailed information on this drug, visit the lenacapavir page in the A-Z of antiretroviral drugs.

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