How does this medication work? What will it do for me?

Maraviroc belongs to the class of medications called CCR5 antagonists. It is used in combination with other medications to treat human immunodeficiency virus (HIV) infection. It works by blocking a receptor called CCR5 that a type of HIV uses to enter cells in your blood called CD4 or T-cells. Maraviroc helps the immune system by reducing the amount of HIV in the blood and increasing the number of CD4 (T) cells.

This medication does not cure HIV infection or AIDS and does not reduce the risk of passing HIV to others through sexual contact or blood contamination.

This medication may be available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of this medication may not be used for all of the conditions discussed here.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

What form(s) does this medication come in?

150 mg
Each blue, biconvex, oval, film-coated tablet, debossed with "Pfizer" on one side and "MVC 150" on the other, contains maraviroc 150 mg. Nonmedicinal ingredients: dibasic calcium phosphate (anhydrous), magnesium stearate, microcrystalline cellulose, and sodium starch glycolate; film-coating: opadry II blue, FD&C Blue No. 2 Aluminum Lake, polyethylene glycol (macrogol 3350), polyvinyl alcohol, soya lecithin, talc, and titanium dioxide.

300 mg
Each blue, biconvex, oval, film-coated tablet, debossed with "Pfizer" on one side and "MVC 300" on the other, contains maraviroc 300 mg. Nonmedicinal ingredients: dibasic calcium phosphate (anhydrous), magnesium stearate, microcrystalline cellulose, and sodium starch glycolate; film-coating: opadry II blue, FD&C Blue No. 2 Aluminum Lake, polyethylene glycol (macrogol 3350), polyvinyl alcohol, soya lecithin, talc, and titanium dioxide.

How should I use this medication?

The usual recommended dose of maraviroc is 300 mg twice daily, taken with or without food. The dose may range from 150 mg to 600 mg twice daily depending on other medications you are taking.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.

It is important to take this medication exactly as prescribed by your doctor. The amount of HIV virus in your blood can increase if this medication is stopped for even a short period of time. Taking this medication exactly as prescribed will also decrease the chance of drug resistance (i.e., the medication stops working to fight HIV).

If you miss a dose, take it as soon as possible and continue with your regular schedule. If it is almost time for your next dose, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

Store this medication at room temperature and keep it out of the reach of children.

Do not dispose of medications in wastewater (e.g. down the sink or in the toilet) or in household garbage. Ask your pharmacist how to dispose of medications that are no longer needed or have expired.

Who should NOT take this medication?

Maraviroc should not be taken by anyone who is allergic to maraviroc or to any of the ingredients of the medication.

What side effects are possible with this medication?

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

  • abdominal pain
  • constipation
  • cough
  • diarrhea
  • difficulty sleeping
  • dizziness, especially when standing from a sitting or lying down position
  • headache
  • itching
  • muscle aches and pains
  • nausea

upper respiratory tract infection (e.g., runny nose, sore throat)Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

  • herpes infection (mouth or genital sores or blisters)
  • signs of infection (e.g., fever, chills, sore throat, mouth ulcers, cough)
  • signs of liver problems (e.g., itchy rash, yellowing of the eyes or skin, dark urine, vomiting, upper right abdominal pain)
  • trouble breathing
  • unexplained muscle aches, soreness, or pain

Stop taking the medication and seek immediate medical attention if any of the following occur:

  • signs of a heart attack (e.g., chest pain, tightness or pressure, nausea, vomiting, sweating, sense of impending doom)
  • signs of a severe allergic reaction (e.g., hives; skin rash; itchy skin; trouble breathing; or swelling of the face, lips, tongue, or throat)
  • signs of a severe skin reaction (e.g., blistering, peeling, a rash covering a large area of the body, a rash that spreads quickly, or a rash combined with fever or discomfort)

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Are there any other precautions or warnings for this medication?

Before you begin taking a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should take this medication.

Blood pressure: Maraviroc may cause dizziness and a drop in blood pressure when you stand from a sitting or lying down position, especially if you are taking medications that lower blood pressure. Get up slowly from a sitting or lying down position while you are taking this medication. If you faint while taking this medication, contact your doctor.

Dizziness: If you experience dizziness while taking maraviroc, do not drive or operate heavy machinery until you are no longer experiencing this side effect.

Heart disease: People with a history of heart disease or people at risk for heart disease should discuss with their doctor how this medication may affect their medical condition, how their medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Hepatitis B or C: People with hepatitis B or C should discuss with their doctor how this medication may affect their medical condition, how their medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

If you experience symptoms of liver problems (itchy rash, yellowing of the eyes or skin, dark urine, vomiting, upper right abdominal pain), stop taking maraviroc and contact your doctor immediately. Continue taking maraviroc and see your doctor immediately if you experience nausea, fever, flu-like symptoms, or fatigue.

Immune reconstitution syndrome: A condition called immune reconstitution syndrome can occur when you start taking HIV medications such as maraviroc. Your immune system may get stronger and start to fight other infections that have been hidden in your body (e.g., pneumonia, herpes, or tuberculosis). Contact your doctor if you develop any new symptoms after starting HIV medications such are maraviroc.

Infections: People taking maraviroc can experience an increase in infections, most commonly, upper respiratory tract infections.. If you experience increased symptoms such as cough, sinus congestion, or sore throat, speak with your doctor.

Kidney function: The safety and effectiveness of maraviroc have not been established for people with reduced kidney function. People with reduced kidney function or kidney disease should discuss with their doctor how this medication may affect their medical condition, how their medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Liver function: Maraviroc may cause liver failure or a decrease in liver function. If you experience symptoms of liver problems (itchy rash, yellowing of the eyes or skin, dark urine, vomiting, upper right abdominal pain), stop taking maraviroc and contact your doctor immediately. Continue taking maraviroc and see your doctor immediately if you experience nausea, fever, flu-like symptoms, or fatigue.

People with reduced liver function or liver disease should discuss with their doctor how this medication may affect their medical condition. Your doctor will monitor your liver function closely while you are taking this medication.

Pregnancy: This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately.

Breast-feeding: It is not known if maraviroc passes into breast milk. However, breast-feeding is not recommended for HIV-positive women since the virus can be passed through breast-milk.

Children: The safety and effectiveness of using this medication have not been established for children less than 18 years of age.

What other drugs could interact with this medication?

There may be an interaction between maraviroc and any of the following:

  • abiraterone acetate
  • amiodarone
  • aprepitant
  • "azole" antifungals (e.g., itraconazole, ketoconazole, voriconazole)
  • bicalutamide
  • boceprevir
  • bosentan
  • calcium channel blockers (e.g., amlodipine, diltiazem, nifedipine, verapamil)
  • carbamazepine
  • cobicistat
  • conivaptan
  • cyclosporine
  • deferasirox
  • desipramine
  • dexamethasone
  • dronedarone
  • enzalutamide
  • fusidic acid
  • grapefruit juice
  • haloperidol
  • HIV non-nucleoside reverse transcriptase inhibitors (NNRTIs; e.g., delaviridine, efavirenz, etravirine, nevirapine)
  • HIV nucleoside reverse transcriptase inhibitors (NRTIs; e.g., abacavir, didanosine, lamivudine, tenofovir, zidovudine)
  • HIV protease inhibitors (e.g., atazanavir, indinavir, ritonavir, saquinavir)
  • ivacaftor
  • lomitapide
  • nefazadone
  • phenobarbital
  • macrolide antibiotics (e.g., clarithromycin, erythromycin)
  • mifepristone
  • mitotane
  • metronidazole
  • modafinil
  • nefazodone
  • norfloxacin
  • phenytoin
  • primidone
  • quinidine
  • rifabutin
  • rifampin
  • St. John's wort
  • sertraline
  • siltuximab
  • simeprevir
  • stiripentol
  • telaprevir
  • telithromycin
  • tetracycline
  • tocilizumab
  • certain tyrosine kinase inhibitors (e.g., ceritinib, crizotinib, dabrafenib, dasatinib, imatinib)

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

  • stop taking one of the medications,
  • change one of the medications to another,
  • change how you are taking one or both of the medications, or
  • leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.