An HIV entry inhibitor (CCR5 antagonist)
Maraviroc
An HIV medicine that blocks the virus from entering cells, used in combination treatment after a special test.
What is Maraviroc?
Maraviroc is an HIV medicine known as an entry inhibitor, or CCR5 antagonist, used as part of combination treatment for HIV. A crucial point is that it only works against one type of HIV, called CCR5-tropic virus, so a special tropism test must be done first to check it will be effective. It is always used alongside other HIV medicines, never on its own. Its important risks include liver problems and allergic reactions, and it can cause dizziness or lightheadedness on standing. It is prescribed and supervised by an HIV specialist team.
Education and reference only. This is a plain-language guide to Maraviroc — it deliberately contains no doses. Doses depend on the person, the brand and the reason for treatment, and belong with your prescriber. Always check the BNF, the product labelling (SmPC) and follow medical advice.
What it is
Maraviroc is a medicine used to treat HIV infection. It belongs to a group called entry inhibitors, and specifically it is a CCR5 antagonist. It is always used as part of combination treatment, meaning it is taken together with other HIV medicines to keep the virus under control. What makes maraviroc unusual is that it only works against a particular type of HIV, so a test has to be carried out before it is started to confirm the virus is the right type. It is taken by mouth as tablets and is prescribed and supervised by a specialist HIV service.
How it works
To infect a cell, HIV has to attach to and enter immune cells, and many strains do this using a doorway on the cell surface called the CCR5 receptor. Maraviroc blocks this CCR5 receptor, so the virus cannot get into the cell, which stops it spreading. Because it only blocks this one doorway, it only works against HIV that uses CCR5 (called CCR5-tropic virus); it does not work against strains that use a different route. This is why a tropism test is essential before starting it, to make sure the person's virus is the type maraviroc can block.
Company & origin
Originated / developed by: Specialist manufacturer.
A specialist HIV medicine used in the UK as part of combination treatment, after a test shows the virus is the right type for it to work.
Practical use
How to take Maraviroc
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- Take it exactly as prescribed, always alongside your other HIV medicines and never on its own.
- Make sure the tropism test has been done first, as maraviroc only works against one type of HIV.
- Take it consistently and do not miss doses, as this keeps the virus controlled and prevents resistance.
- Report any rash, fever, yellowing of the skin or eyes, or feeling generally unwell, as these can signal liver or allergic reactions.
- Take care when standing up, as it can cause dizziness or lightheadedness.
Weighing it up
Advantages & disadvantages of Maraviroc
Advantages
- Offers a different way of controlling HIV by blocking the virus from entering cells.
- A useful option in combination treatment, particularly when other medicines are less suitable.
- Taken by mouth as tablets as part of a daily HIV regimen.
Disadvantages
- Only works against CCR5-tropic HIV, so a tropism test is needed before it can be used.
- Carries a risk of liver problems and allergic-type reactions.
- Can cause dizziness or lightheadedness, particularly on standing, and interacts with several medicines.
Practical use
Good to know
The single most important thing about maraviroc is that it only works against CCR5-tropic HIV, so a tropism test must be done first; if the virus uses a different route, the medicine will not work. It is always part of a combination of HIV medicines and is never taken alone, because using one medicine on its own lets the virus become resistant. Two key safety points are the risk of liver problems, sometimes preceded by an allergic-type reaction with rash or fever, which should be reported urgently, and the chance of feeling dizzy or lightheaded, especially on standing up, so care is needed. Like all HIV treatment, it works best when taken regularly and consistently, as missed doses can let the virus rebound and become resistant.
Who should not take it / use with caution
- People whose HIV is not CCR5-tropic, as the medicine will not work against their virus.
- People who have had a serious allergic reaction to maraviroc should not take it.
- It is used with care, and the dose adjusted, in people with kidney or liver problems, under specialist guidance.
Monitoring
- A tropism test before starting to confirm the virus is the right type.
- Regular blood tests to check liver function and how well HIV is controlled.
- Watching for allergic-type reactions, dizziness and signs of infection.
Side effects
- Dizziness or lightheadedness, especially on standing.
- Liver problems, sometimes with an allergic-type reaction such as rash or fever, which need urgent attention.
- Tummy upset, cough, cold-like symptoms or rash in some people.
Key interactions
- Several other medicines can raise or lower maraviroc levels, so the dose is often adjusted accordingly.
- Some other HIV medicines and certain antibiotics or antifungals affect how it works.
- Tell your team about all medicines, including herbal products such as St John's wort, which can reduce its effect.
Available as: Tablets taken by mouth, with an oral liquid for some people.
Answers
Maraviroc: frequently asked questions
What is maraviroc used for?
It is an HIV medicine, an entry inhibitor, used as part of combination treatment to help control HIV by stopping the virus from getting into cells.
Why do I need a test before starting it?
Maraviroc only works against CCR5-tropic HIV, so a tropism test is done first to make sure your virus is the type it can block; otherwise it would not work.
Can I take it on its own?
No. Maraviroc is always used together with other HIV medicines; taking one HIV medicine alone lets the virus become resistant.
What serious side effects should I watch for?
Report any rash, fever, yellowing of the skin or eyes, or feeling generally unwell urgently, as maraviroc can cause liver problems and allergic-type reactions.
Why might I feel dizzy?
Maraviroc can cause dizziness or lightheadedness, particularly when standing up, so take care when changing position until you know how it affects you.
The wider class
About HIV entry inhibitor (CCR5 antagonist)
Maraviroc belongs to the hiv entry inhibitor (ccr5 antagonist) class. For how the class as a whole works, its shared safety principles and monitoring, see the full guide.
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Authoritative sources
- BNF
- NICE CKS
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