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Opsumit
Macitentan
$8700.00
10mg · 3 × 30 tablets · 3 months supply
BrandBranded medicine· By Janssen Cilag
$2900.00 per month
How long a supply?
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Annual cost
$34800a year at this pack size
Prescription required
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FDA boxed warningEmbryo-fetal toxicity
OPSUMIT is contraindicated for use during pregnancy because it may cause fetal harm based on animal data
Therefore, for females of reproductive potential, exclude pregnancy before the start of treatment with OPSUMIT. Advise use of effective contraception before the initiation of treatment, during treatment, and for one month after stopping treatment with OPSUMIT
When pregnancy is detected, discontinue OPSUMIT as soon as possible
Based on animal data, OPSUMIT may cause fetal harm if used during pregnancy.
Females of reproductive potential: exclude pregnancy before start of treatment. Prevent pregnancy prior to initiation of treatment, during treatment and for one month after treatment by using effective methods of contraception.
About Opsumit
Overview
Opsumit (macitentan) is a prescription medicine called an endothelin receptor antagonist. It is used in adults with pulmonary arterial hypertension (PAH, WHO Group I) to reduce the risks of disease progression and hospitalization for PAH. It works by blocking endothelin, a substance involved in narrowing blood vessels and changes to blood vessel walls in PAH, from binding to its receptors.
What it treats
Pulmonary arterial hypertension (PAH, WHO Group I) in adults, to reduce the risks of disease progression and hospitalization for PAH.
Safety information
Side effects
Common side effects include anemia (low red blood cells), inflammation of the nose or throat, bronchitis, headache, flu and urinary tract infection. Serious risks include liver injury or liver failure, fluid retention that may need treatment, decreased hemoglobin (the protein in red blood cells that carries oxygen), and pulmonary edema (fluid in the lungs) in people with pulmonary veno-occlusive disease. Contact your doctor if you develop or suspect any of these problems. Liver enzyme tests are needed before treatment and during treatment as clinically indicated. Opsumit can harm an unborn baby. Contact your doctor if you are pregnant or think you may be pregnant. Decreased sperm counts have also been observed with medicines in this class.
FDA boxed warning
Embryo-fetal toxicity
OPSUMIT is contraindicated for use during pregnancy because it may cause fetal harm based on animal data
Therefore, for females of reproductive potential, exclude pregnancy before the start of treatment with OPSUMIT. Advise use of effective contraception before the initiation of treatment, during treatment, and for one month after stopping treatment with OPSUMIT
When pregnancy is detected, discontinue OPSUMIT as soon as possible
Based on animal data, OPSUMIT may cause fetal harm if used during pregnancy.
Females of reproductive potential: exclude pregnancy before start of treatment. Prevent pregnancy prior to initiation of treatment, during treatment and for one month after treatment by using effective methods of contraception.
A boxed warning is the strongest warning the US Food and Drug Administration requires on a medicine label. Text is taken from the official label, with internal section references removed.
When to call your doctor
If symptoms are severe or getting worse quickly, seek emergency care rather than waiting.
Before taking this medicine
Do not take Opsumit if you are pregnant or allergic to macitentan or any of its ingredients. Do not breastfeed while taking it. Opsumit belongs to a class of medicines called endothelin receptor antagonists (ERAs), which can cause liver damage and liver failure. Liver enzymes should be checked before treatment and monitored as clinically needed. Other concerns include fluid retention, which may require treatment, and reduced hemoglobin levels. Fluid buildup in the lungs can occur in people with pulmonary veno-occlusive disease; treatment must be stopped if this condition is confirmed. Reduced sperm counts have been observed in people taking ERAs.
Interactions
Avoid taking Opsumit with rifampin, which lowers macitentan levels, or with ketoconazole or ritonavir, which raise them. Fluconazole and amiodarone may also raise macitentan levels and should be avoided with Opsumit. Other medicines that strongly affect the liver enzyme CYP3A4, or combinations that block both CYP3A4 and CYP2C9, should also be avoided. Ask your doctor to check your medicines for these interactions.
Using Opsumit
Dosing
Dosing is set by your prescriber. Each health care professional may prescribe medication differently according to a patient's medical history and condition, so follow the directions on your prescription label and speak to your doctor or pharmacist before changing anything.
Storage
Store below 25°C in a dry place, in the original pack, away from direct light and moisture. Do not keep it in a bathroom. Keep all medicines out of the sight and reach of children.
Clinical information on this page is summarised from the US FDA label OPSUMIT (MACITENTAN) TABLET, FILM COATED [ACTELION PHARMACEUTICALS US, INC.] (DailyMed, retrieved 19 September 2026).
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