Indications
Macitentan is used for the long-term treatment of pulmonary arterial hypertension (PAH) in adults who are in WHO functional class (FC) II to III. It has also been shown to work in several types of PAH, including idiopathic and heritable PAH, PAH associated with connective tissue disorders, and PAH associated with congenital heart disease.
⚠️ Always consult a registered physician before taking any medicine.
Pharmacology
Endothelin (ET)-1 and its receptors (ETA and ETB) cause a number of harmful effects, including vasoconstriction, fibrosis, proliferation, hypertrophy and inflammation. In diseases such as PAH, the local ET system is upregulated, and this plays a part in vascular hypertrophy and organ damage.
Macitentan is an endothelin receptor antagonist. It blocks the binding of ET-1 to both ETA and ETB receptors. In human pulmonary arterial smooth muscle cells, macitentan shows high affinity and stays on the ET receptors for a long time.
One of the metabolites of macitentan is also active at the ET receptors. In vitro, it is estimated to be about 20% as potent as the parent drug. The clinical impact of dual endothelin blockage is unknown.
Pregnancy & Breastfeeding
Doctors should start Macitentan in a woman who could become pregnant only after they have confirmed that she is not pregnant. She should also avoid becoming pregnant for 1 month after she stops taking Macitentan. A pregnancy test every month during treatment is recommended, so that a pregnancy can be picked up early.
It is not known whether Macitentan passes into human milk. Macitentan is contraindicated during breastfeeding.
Male fertility
Testicular tubular atrophy was seen in male animals treated with Macitentan. Whether this matters for humans is unknown, but sperm production (spermatogenesis) could get worse.
⚠️ Talk to your doctor before taking any medicine during pregnancy or while breastfeeding.
Dosage Reference
⚠️ Reference ranges from official sources only. Consult your doctor for personalized dosing.
Side Effects & Interactions
Side Effects
No side-effect data recorded yet.