Celsentri (Maraviroc)

How does it work?

Celsentri tablets contain the active ingredient maraviroc, which is a type of medicine called a CCR5 antagonist. It is used in the treatment of HIV (human immunodeficiency virus) infection.

AIDS (acquired immune deficiency syndrome) is caused by infection with HIV. This virus invades cells of the immune system, particularly the white blood cells known as CD4 T-helper lymphocytes. These cells normally work to activate other cells in the immune system to fight infection. Since HIV kills CD4 T-helper cells, over time the body becomes less able to fight the virus or subsequent infections.

Maraviroc works by binding to a protein on the outside of the CD4 T-helper cells known as the CCR5 receptor. With maraviroc bound to this protein, the virus is prevented from fusing with the CD4 cell membrane. This stops it injecting its genetic material into the cell. The virus can only replicate and increase in numbers once its genetic material is inside CD4 cells, so maraviroc stops the virus from replicating.

Maraviroc is only licensed for people who have been identified as being infected with a strain of the HIV-1 virus called CCR5-tropic. This is the only strain of HIV that uses the CCR5 receptor to gain entry to the CD4 cells.

This mechanism of action is different from most of the other currently available anti-HIV drugs, which only work once the virus has infected the CD4 cells. Maraviroc is active against strains of HIV that have become resistant to other anti-HIV medicines.

There is no cure for HIV, but maraviroc, is one of a number of anti-HIV medicines that lower the amount of virus in the body (viral load) and slow the progression of the disease from HIV to AIDS. Maraviroc must be used in conjunction with other anti-HIV drugs that attack the HIV virus in different ways. It is added to existing treatment in people who are failing an antiretroviral regimen because their virus has become resistant, and is not responding to the existing treatment.

What is it used for?

  • HIV infection.


  • Celsentri is reserved for people infected with a strain of HIV-1 virus called CCR5-tropic. A test known as a tropism assay will be carried out before treatment with this medication is started. This involves a blood test to determine the strain of HIV.
  • The HIV virus is very good at becoming resistant to anti-HIV medicines. For this reason it is very important that you carefully follow your doctor's instructions for taking your anti-HIV medicines, in order to maintain effective levels of the medicines in your blood. If the blood levels drop, the virus will be given more chance to replicate and develop resistance to the drugs. Skipping even a few doses increases the risk of treatment failure, so you should try to ensure that you take all your doses at the correct time, and that you visit your doctor for repeat prescriptions before you run out of medicine.
  • Treatment of HIV infection with anti-HIV medicines such as this one does not reduce the risk of transmitting the virus to other people through sexual contact or blood contamination. You should continue to use condoms to prevent transmitting the virus to your sexual partner.
  • Some people being treated with combination antiretroviral therapy may develop a bone condition called osteonecrosis. This condition is caused by loss of blood supply to a bone, causing death of the bone tissue. The risk of the condition is thought to be increased by corticosteroid use, alcohol consumption, severe immunosuppression, higher body mass index, advanced HIV disease and long-term use of antiretroviral medicines. If you notice any joint stiffness, aches and pains (especially of the hip, knee and shoulder) or difficulty in movement while using this medicine, you should tell your doctor so this can be investigated.
  • You will need to have regular blood tests to monitor your liver function while you are taking this medicine. This is especially important if you already have any problems with your liver, in particular chronic hepatitis B or C. Symptoms that may suggest a liver problem include persistent nausea and vomiting, abdominal pain, or the development of jaundice (a yellow colouring to the skin and the whites of the eyes). Consult your doctor if you experience any of these symptoms.
  • Treatment with this medication may increase the risk of developing infections, such as fungal infections. If you notice any symptoms of infection, such as inflammation, it is necessary to see a doctor.

Use with caution in

  • Elderly people.
  • People with history of low blood pressure or taking any medication to lower blood pressure.
  • Decreased kidney function.
  • Decreased liver function.
  • Hepatitis, particularly chronic Hepatitis B or C.
  • Severe disease affecting the heart and blood vessels (cardiovascular disease).
  • Tuberculosis.
  • Invasive fungal infections.

Not to be used in

  • Children.
  • Celsentri tablets contain soya lecithin and are unsuitable for people with an allergy to peanuts or soya.

This medicine should not be used if you are allergic to any of its ingredients. Please inform your doctor or pharmacist if you have previously experienced such an allergy.

If you feel you have experienced an allergic reaction, stop using this medicine and inform your doctor or pharmacist immediately.

Pregnancy and breastfeeding

Certain medicines should not be used during pregnancy or breastfeeding. However, other medicines may be safely used in pregnancy or breastfeeding providing the benefits to the mother outweigh the risks to the unborn baby. Always inform your doctor if you are pregnant or planning a pregnancy, before using any medicine.

  • The safety of this medicine for use during pregnancy has not been established. It is not recommended for use in pregnancy unless the potential benefit outweighs any risks to the developing foetus. Seek medical advice from your doctor.
  • It is not known if this medicine passes into breast milk. It is recommended that women infected with the HIV virus must not breastfeed their infants under any circumstances, in order to avoid transmission of the virus to the baby. Seek medical advice from your doctor.

Side effects

Medicines and their possible side effects can affect individual people in different ways. The following are some of the side effects that are known to be associated with this medicine. Just because a side effect is stated here does not mean that all people using this medicine will experience that or any side effect.

  • Disturbances of the gut, such as nausea and vomiting, bloating, indigestion, abdominal pain, constipation, diarrhoea.
  • Headache.
  • Dizziness.
  • Cough.
  • Fatigue, weakness or loss of strength (asthenia).
  • Difficulty sleeping (insomnia).
  • Skin reactions such as rash, itching.
  • Pins and needles or numb sensations.
  • Pain in the muscles or joints.
  • Shortness of breath (dyspnoea).
  • Epilepsy.
  • Fainting (syncope).
  • Increased production of urine (polyuria).
  • Kidney failure.
  • Loss of muscular movement in the face (face palsy).
  • Bleeding from the rectum.
  • Inflammation of the pancreas (pancreatitis).
  • Blood disorders.
  • Hallucinations.
  • Heart attack.

The side effects listed above may not include all of the side effects reported by the medicine's manufacturer.

For more information about any other possible risks associated with this medicine, please read the information provided with the medicine or consult your doctor or pharmacist.

How can this medicine affect other medicines?

It is important to tell your doctor or pharmacist what medicines you are already taking, including those bought without a prescription and herbal medicines, before you start treatment with this medicine. Similarly, check with your doctor or pharmacist before taking any new medicines while taking this one, to ensure that the combination is safe.

The following medicines may prevent the breakdown of maraviroc by the liver and so could increase the amount of maraviroc in the blood. If you are prescribed any of these while taking maraviroc you should let your doctor know if you get any new or worsening side effects, as your doctor may need to reduce your dose of maraviroc:

  • atazanavir
  • clarithromycin
  • darunavir
  • indinavir
  • itraconazole
  • ketoconazole
  • lopinavir
  • nelfinavir
  • saquinavir
  • telithromycin.

The following medicines may increase the breakdown of maraviroc by the liver. As this could decrease the level of maraviroc in the blood and may therefore make it less effective, your doctor may need to increase your maraviroc dose if you are prescribed any of these:

  • efavirenz
  • rifampicin
  • the herbal remedy St John's wort (Hypericum perforatum). This should not be taken by people taking maraviroc.

Other medicines containing the same active ingredient

There are currently no other medicines available in the UK that contain maraviroc as the active ingredient.