macitentan at a glance
Medicine class
Endothelin receptor antagonist
Main use
Specialist management of pulmonary arterial hypertension
Food
May be taken with or without food
Monitoring
Liver function, haemoglobin and pregnancy status may need monitoring
What is macitentan used for?
Macitentan is licensed for pulmonary arterial hypertension with WHO functional class II to III symptoms.
Adults may receive the film-coated formulation under specialist supervision.
Children aged 2 years and over may receive an appropriate formulation, depending on age, weight and ability to take the preparation.
How does macitentan work?
Endothelin-1 contributes to narrowing, inflammation and thickening of pulmonary blood vessels. Macitentan blocks ETA and ETB endothelin receptors, reducing these signals and resistance to blood flow through the lungs.
macitentan preparations and strengths
Dispersible tablet
Route: Oral
Strengths: 2.5 mg
Tablet
Route: Oral
Strengths: 10 mg
How to take macitentan
Follow the pulmonary hypertension team's instructions and use only the prescribed formulation.
Swallow the film-coated tablet whole with water; it is not designed to be broken.
Dispersible tablets must be mixed in room-temperature liquid and taken as an oral suspension. Follow the supplied preparation instructions, rinse the glass, and discard a prepared suspension if it has stood for more than 2 hours.
Either formulation may be taken with or without food.
macitentan side effects
Common or expected effects
- Headache
- Anaemia or reduced haemoglobin
- Cold-like symptoms, sore throat or bronchitis
- Fluid retention or swelling
- Flushing, nasal congestion or low blood pressure
- Raised liver enzymes
- Increased or irregular uterine bleeding
Get urgent medical advice
- Facial, lip, tongue or throat swelling, particularly with breathing difficulty
- Symptoms of liver injury, such as jaundice or dark urine
- Severe dizziness, fainting or symptomatic low blood pressure
- Marked new breathlessness or rapidly worsening swelling
macitentan in pregnancy
Macitentan is contraindicated during pregnancy. Pregnancy should be excluded before treatment; reliable contraception and regular pregnancy testing are required. Contact the specialist team promptly if pregnancy is suspected, and do not stop prescribed treatment without specialist advice.
macitentan while breastfeeding
Macitentan is contraindicated during breastfeeding. It is unknown whether it enters human milk, and a risk to the child cannot be excluded; discuss feeding and treatment options with the specialist team.
macitentan interactions
Check prescription, non-prescription and herbal products with the specialist team or pharmacist.
Rifampicin, carbamazepine, phenytoin and St John's wort
Strong CYP3A4 induction can substantially reduce macitentan exposure and effectiveness, so these combinations should be avoided.
Ketoconazole, itraconazole, voriconazole, clarithromycin and some HIV protease inhibitors
Strong CYP3A4 inhibition may raise macitentan exposure; specialist review and caution are required.
Fluconazole or amiodarone
Combined CYP3A4 and CYP2C9 inhibition may substantially increase macitentan exposure, requiring caution.
Common questions about macitentan
Answers are fully visible for fast scanning and source review.
What is macitentan used for?
Macitentan is used by specialist teams to manage pulmonary arterial hypertension with WHO functional class II to III symptoms.
How does macitentan help pulmonary arterial hypertension?
It blocks endothelin receptors, reducing signals that narrow and thicken pulmonary blood vessels.
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.