Opsumit (Macitentan) Dosages: Your GoodRx Guide

If you’re an adult living with pulmonary arterial hypertension (PAH), your healthcare team may recommend a medication like Opsumit (macitentan). Opsumit is often taken in combination with other PAH medications, such as tadalafil (Adcirca), to help people avoid hospitalization and slow the progression of the disease.

Before starting treatment with Opsumit, there are a few things you should know. Below, we cover the recommended Opsumit dosage, how to handle a missed dose, and more.

Before starting Opsumit

If there’s a possibility you could get pregnant, there are some additional steps you’ll need to take when you’re prescribed Opsumit. That’s because the medication has a boxed warning, the FDA’s strictest medication warning, about the potential for harm to a growing fetus.

To avoid this possibility, you’ll be enrolled in a Risk Evaluation and Mitigation Strategies (REMS) program. The program requires a negative pregnancy test prior to starting treatment with Opsumit. And you’ll need to take monthly pregnancy tests during treatment. If you stop taking Opsumit, a final pregnancy test is required 1 month after your last dose. As part of the program, you’ll also be asked to use effective birth control methods to prevent pregnancy.

If you’re a man and having children is important to you, you should also speak to your prescriber before starting Opsumit. The medication may decrease your sperm count, which could affect your ability to have a child. 

What’s the typical Opsumit dosage?

Opsumit is available in a 10 mg tablet. The FDA-approved Opsumit dosage is 10 mg by mouth once daily. Higher dosages have not been studied in people with PAH. You can take Opsumit with or without food, at any time of the day. Though, it’s helpful to pick a specific time and stick with it.

What happens if you miss a dose of Opsumit?

If you miss a dose of Opsumit, take the medication as soon as you remember. If you do not remember until it is almost time for your next dose, skip the missed one and take your next dose at the regular time. You should not take an extra dose of Opsumit to make up for a missed one.

What should you do if you take too much Opsumit?

If you take too much Opsumit, you may experience symptoms such as headache, nausea, and vomiting. If you believe you’ve taken too much of the medication, inform your prescriber right away. They will walk you through the next steps. You can also contact Poison Control online or at 1-800-222-1222 for guidance. If you have any symptoms that feel life-threatening, call 911 or go to the nearest ER.

How to save on Opsumit

Opsumit is considered a specialty medication. That means you’ll likely receive it in the mail from a specialty pharmacy. If you have health insurance, the pharmacy staff will work with your insurance provider on coverage details. They will also help you determine if you’re eligible for financial assistance.

If you have commercial insurance and qualify, you could pay as little as $5 for Opsumit with a copay savings card from the manufacturer. Or if you don’t have insurance, you may qualify for the manufacturer’s patient assistance program. Your specialty pharmacy can help you navigate ways to save on the medication.

Why trust our experts?

Written by:

Gabrielle Colina, PharmD

Gabrielle has 14 years of experience in community pharmacy. During her senior year of high school, she worked as a pharmacy technician at a local retail pharmacy.

Edited by:

Alyssa Billingsley, PharmD

Alyssa Billingsley, PharmD, is the director of pharmacy content for GoodRx. She has over a decade of experience as a pharmacist and has worked in clinical, academic, and administrative roles.

Reviewed by:

Bailey E. Eason, PharmD, MS, BCPS

Bailey Eason has been licensed for 6 years and has held licenses in three states (North Carolina, Virginia, and Illinois). She has held positions as a health-system pharmacy administration resident, operating room pharmacy manager, pharmacy manager of clinical operations: surgery, neurology and controlled substances, and most recently as program director  of drug diversion for a large academic health system.

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