Opsumit (Macitentan)

Description

Opsumit, also known by its generic name Macitentan, is an endothelin receptor antagonist that serves as a treatment for pulmonary arterial hypertension (PAH, WHO Group I). By blocking the action of endothelin, a substance in the walls of blood vessels that causes them to narrow, Opsumit helps to relax and widen these vessels. Classified as a long-term treatment option, the drug aims to slow down the progression of PAH and can improve the ability to exercise.

Directions

When taking Opsumit, it's important to follow a healthcare provider’s instructions. The usual dosage is 10 mg once daily and can be taken with or without food. When consuming this medication, be aware that higher doses than 10 mg have not been studied extensively in individuals with PAH and are generally not recommended. Always swallow tablets whole, avoiding crushing or splitting them, as this could affect how the drug works.

Ingredients

Opsumit tablets contain the active ingredient Macitentan alongside several inactive ingredients that ensure the tablet's stability and promote its absorption. These inactive ingredients may include lactose, magnesium stearate, microcrystalline cellulose, polysorbate 80, povidone, and sodium starch glycolate type A.

Contraindications

Avoid taking or using this medication if any of the following apply:

• Pregnancy: There is a significant risk of harm to the fetus if a person takes Opsumit while pregnant
• Allergies to Macitentan: If you have had an allergic reaction to Macitentan or any other ingredients in this medication

Cautions

• Before starting treatment with Opsumit, inform your healthcare provider about:
• Any existing medical conditions
• Any medications you are taking
• If you are or plan to become pregnant
• If you are breastfeeding
• Opsumit, like other ERAs, can potentially cause liver damage and, in rare cases, lead to liver failure. It’s important to check liver enzyme levels before starting the treatment and monitor them regularly, as advised by your healthcare provider.
• Patients on Opsumit may experience fluid retention, which, in some cases, might require medical attention. It's vital to be vigilant for symptoms like swelling of limbs or sudden weight gain and report these to your doctor.
• A decrease in hemoglobin levels has been observed in individuals taking Opsumit. Regular blood tests to monitor these levels can be an important part of managing your health while on this medication.
• In patients with pulmonary veno-occlusive disease, there's a risk of developing pulmonary edema (accumulation of fluid in the lungs) while on Opsumit. If this condition occurs, stopping the medication is necessary.
• Opsumit has been associated with a decrease in sperm count in some patients. This is an important consideration for men looking to start a family and should be discussed with a healthcare professional.

Side Effects

Side effects are possible while taking Opsumit. Common Opsumit side effects may include stuffy nose or sore throat, bronchitis, headaches, flu symptoms, and urinary tract infections. More severe side effects linked to Opsumit include the risk of serious birth defects, liver problems (with symptoms like nausea, yellowing of the skin or eyes, and dark urine), fluid retention (seen as unexpected weight gain or swelling in ankles or legs), anemia, and reduced sperm counts in men. Regular check-ups and communication with a healthcare provider are recommended for managing the risk of side effects.

References:

1. Opsumit (Macitentan) Product Monograph. Titusville, NJ: Actelion Pharmaceuticals; 2023.
2. Opsumit (Macitentan) Drug Label Information. Titusville, NJ: Actelion Pharmaceuticals; 2023.

About Dr. Gerardo Sison (Page Author)

An honors graduate of the University of Florida, Dr. Sison started his pharmacy career in a community setting, extending his services to hospitals and clinics over time. He has also worked in medication therapy management, advising patients on proper medication use for their chronic health conditions. Read More....