Opsumit

The active ingredient in Opsumit is macitentan. Macitentan belongs to a class of medications known as endothelin receptor antagonists (ERA). These inhibitors block the actions of endothelin, which are involved in promoting vasoconstriction, fibrosis, scar tissue formation, and inflammation. All 3 of these properties can contribute to elevated pressure.

Follow all directions given to you by your doctor and read all documents provided, including the full Prescribing Information, FDA-Approved Product Labeling, Instructions for Use, and Medication Guide before using Opsumit. However, the following is a synopsis of the general guidelines for the use of Opsumit:

• Opsumit should be used exactly as prescribed. Before starting, your prescriber will have you undergo blood tests to check your liver function.
• It is typically taken once daily with or without food.
• Females of childbearing potential should use an effective form of birth control while taking Opsumit. Tell your doctor right away if you miss a period or think you could be pregnant.
• Because Opsumit can cause life-threatening harm to unborn babies, it is only available through a Risk Evaluation and Mitigation Strategy (REMS) program. All women who can get pregnant, their provider, and the pharmacy must be registered with this program. Talk to your provider or pharmacist for more information.
• If you miss a dose, take it as soon as you remember. However, if it is the following day, skip the missed dose and continue with your regular dosing schedule. Do not take 2 doses on the same day to make up for a missed dose.

The most common side effects of Opsumit seen in clinical trials as compared to placebo include:

• Anemia or low red blood cells
• Cold & flu-like symptoms such as a stuffy nose and sore throat
• Bronchitis
• Headache
• Urinary tract infections (UTIs)

Some individuals may experience serious side effects while using Opsumit. These side effects may require immediate medical attention. If you experience any of the following, contact your healthcare provider or seek emergency medical help:

• Signs of liver problems such as upper right abdominal pain, nausea, vomiting, loss of appetite, yellowing of the skin and whites of your eyes, and dark urine.
• Unexplained weight gain or swelling. These could be signs of fluid retention.
• Shortness of breath and chest pain, especially in those with heart failure. This, along with edema or fluid retention, could be signs of a worsening condition.
• Fertility issues in men. Opsumit can decrease sperm count.

These are not all of the possible side effects of Opsumit. You should always seek medical advice from your healthcare provider for any questions or concerns about your medical condition or treatment. Read all patient information, medication guides, or drug information sheets that come with this medication. You can also report adverse effects to the Food and Drug Administration at www.fda.gov/medwatch or 1-800-FDA-1088.

Before starting Opsumit, it is crucial to discuss any existing health conditions with your healthcare provider. You should be sure that your healthcare provider is aware of all your medical conditions, including:

• Liver problems
• Heart disease
• Low hemoglobin levels
• Pulmonary veno-occlusive disease
• Issues with sperm count

Boxed Warning

• Opsumit should not be used in pregnancy due to the risk of fetal harm and birth defects.
• Females of reproductive potential should perform a pregnancy test before using and use an effective form of contraception throughout treatment and for one month after stopping treatment. If pregnancy is detected, discontinue use immediately.

Do not use Opsumit if you:

• Are pregnant
• Have an allergy to macitentan or any of the other ingredients in Opsumit

Opsumit begins to work right after the first dose. However, it can take several weeks or months of regular use to see the full benefits.

When Opsumit is taken with other prescription drugs, over-the-counter medications, vitamins, and supplements, it may change how they work or increase the frequency or severity of side effects. Make sure that you tell your healthcare professional about anything that you are taking to avoid any negative drug interactions, including:

• Rifampin
• Ketoconazole
• Ritonavir
• Fluconazole
• Amiodarone

Opsumit is available as 10 mg film-coated tablets.

Opsumit should be stored at room temperature, away from light and moisture, and out of reach of children.

Opsumit is manufactured by the pharmaceutical company Actelion Pharmaceuticals US.

Currently, there is no generic available for Opsumit.

Consult your doctor or pharmacist before starting, stopping, or changing medications while taking Opsumit.

Do not use Opsumit during pregnancy. Talk to your doctor if you are already pregnant or if you have any plans to become pregnant. They will know or recommend what is best for you.

Do not breastfeed while using Opsumit. It is unknown if it passes into breast milk. Talk to your doctor if you are already breastfeeding or if you have any plans to breastfeed. They will know or recommend what is best for you.