Note: This document contains side effect information about macitentan. Some dosage forms listed on this page may not apply to the brand name Opsumit.

Applies to macitentan: oral tablet.

Serious side effects of Opsumit

Along with its needed effects, macitentan (the active ingredient contained in Opsumit) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking macitentan:

More common

• Decrease in the amount of urine
• noisy, rattling breathing
• pale skin
• swelling of the fingers, hands, feet, or lower legs
• troubled breathing with exertion
• unusual bleeding or bruising
• unusual tiredness or weakness
• weight gain

Less common

• Abdominal or stomach pain or tenderness
• clay colored stools
• dark urine
• difficult, burning, or painful urination
• frequent urge to urinate
• lower back or side pain
• muscle aches and pains
• difficulty with breathing
• tightness in the chest
• yellow eyes or skin

Other side effects of Opsumit

Some side effects of macitentan may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

• Chills or fever
• cough
• sore throat
• stuffy or runny nose

For Healthcare Professionals

Applies to macitentan: oral tablet.

General

The most common adverse reactions are peripheral edema, upper respiratory tract infection, nasopharyngitis, headache, anemia, and bronchitis.^[Ref]

Respiratory

Very common (10% or more): Upper respiratory tract infection (15.3%), nasopharyngitis (14%), bronchitis (11.6%)

Common (1% to 10%): Viral respiratory tract infection, pharyngitis, sinusitis, rhinitis, lower respiratory tract infection, tracheitis, tonsillitis, rhinorrhea, productive cough, bronchial hyperreactivity

Frequency not reported: Pulmonary edema

Postmarketing reports: Nasal congestion^[Ref]

Hematologic

Very common (10% or more): Anemia (13.2%)

Common (1% to 10%): Thrombocytopenia, hemoglobin decreased, hematocrit decreased

Frequency not reported: Decrease in mean leukocyte count, decrease in mean platelet count^[Ref]

Cardiovascular

Very common (10% or more): Peripheral edema (18.2%)

Common (1% to 10%): Hypotension, flushing^[Ref]

Nervous system

Very common (10% or more): Headache (13.6%)

Common (1% to 10%): Migraine^[Ref]

Gastrointestinal

Common (1% to 10%): Diarrhea, upper abdominal pain, gastroenteritis, abdominal pain, irritable bowel syndrome, hemorrhoids, viral gastroenteritis^[Ref]

Genitourinary

Common (1% to 10%): Urinary tract infection, metrorrhagia, menorrhagia, ovarian cyst

Frequency not reported: Adverse effects on spermatogenesis affecting male fertility^[Ref]

Dermatologic

Common (1% to 10%): Skin ulcer, pruritus, eczema, urticaria

Postmarketing reports: Angioedema, rash^[Ref]

Musculoskeletal

Common (1% to 10%): Arthralgia, myalgia, systemic sclerosis, costochondritis^[Ref]

Hepatic

Common (1% to 10%): Cholelithiasis, elevated aminotransferases

Frequency not reported: Hepatotoxicity, liver failure^[Ref]

Metabolic

Common (1% to 10%): Hypokalemia, blood urea increased^[Ref]

Psychiatric

Common (1% to 10%): Insomnia, depression^[Ref]

Other

Common (1% to 10%): Pyrexia, gynecomastia^[Ref]

Immunologic

Common (1% to 10%): Influenza^[Ref]

Ocular

Common (1% to 10%): Conjunctivitis^[Ref]