Opsumit

Macitentan is used to treat high blood pressure in the lungs (pulmonary arterial hypertension). This condition is thought to be caused by increased levels of a certain natural substance (endothelin-1). This medication blocks the effects of endothelin-1, which helps decrease the blood pressure in the lungs, and reduces the risk of worsening of symptoms and hospital stays due to the disease.

Read the Medication Guide and, if available, the Patient Information Leaflet provided by your pharmacist before you start taking macitentan and each time you get a refill. If you have any questions, ask your doctor or pharmacist.

Take this medication by mouth with or without food as directed by your doctor, usually once daily. Swallow the tablet whole. Do not split, crush, or chew the tablet.

Use this medication regularly to get the most benefit from it. To help you remember, take it at the same time each day.

Do not increase your dose or use this drug more often or for longer than prescribed. Your condition will not improve any faster, and your risk of side effects will increase.

Since this drug can be absorbed through the skin and lungs and may harm an unborn baby, women who are pregnant or who may become pregnant should not handle this medication or breathe the dust from the tablets.

Tell your doctor if your condition does not improve or if it worsens.

Runny nose, sore throat, cough, headache, chills, or body aches may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.

Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tell your doctor right away if you have any serious side effects, including: signs of low red blood cell count (such as unusual tiredness, rapid breathing, pale skin, shortness of breath, fast heartbeat), unusual weight gain, new or worsening swelling of the hands/ankles/feet.

Macitentan may rarely cause serious liver disease. Tell your doctor right away if you have any symptoms of liver disease, including: dark urine, persistent nausea/vomiting/loss of appetite, stomach/abdominal pain, yellowing eyes/skin.

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Before taking macitentan, tell your doctor or pharmacist if you are allergic to it; or to other endothelin receptor blockers (such as bosentan); or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of: anemia, other lung conditions (such as pulmonary veno-occlusive disease).

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

This medication can affect fertility in males. Ask your doctor for more details.

This medication must not be used during pregnancy. It may harm an unborn baby. See also Warning section.

Since this drug can be absorbed through the skin and lungs and may harm an unborn baby, women who are pregnant or who may become pregnant should not handle this medication or breathe the dust from the tablets.

It is unknown if this medication passes into breast milk. Because of the possible risk to the infant, breast-feeding while using this drug is not recommended. Consult your doctor before breast-feeding.

Store at room temperature away from light and moisture. Do not store in the bathroom. Keep all medications away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.

Other medications can affect the removal of macitentan from your body, which may affect how macitentan works. Examples include azole antifungals (such as ketoconazole), cobicistat, macrolide antibiotics (such as clarithromycin), HIV protease inhibitors (such as ritonavir), rifamycins (such as rifampin), among others.

If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center.

If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up.

Do not share this medication with others.

Laboratory tests (such as liver function tests, pregnancy tests, hemoglobin) should be performed before you start treatment, periodically to monitor your progress, or to check for side effects. Consult your doctor for more details.