Macitentan was approved in October 2013. It is indicated for patients with pulmonary arterial hypertension, and is marketed under the brand name Opsumit. Macitentan is an antagonist/blocker of endothelin receptors on blood vessels and smooth muscle, and, thus, blocks the stimulation of vasculature hypertrophy, inflammation, fibrosis, proliferation, and vasoconstriction. Similar to all drugs acting on the renin-angiotensin system, opsumit is associated with embryo and fetal toxicity, so it should not be used in pregnancy and has special precautions that must be followed for all females of child-bearing age.
Macitentan blocks simulators of hypertrophy, inflammation, fibrosis, proliferation, and vasoconstriction.
Macitentan has a black box warning of embryo-fetal toxicity. Special precautions must be taken for all females of child-bearing age, and women who are pregnant must not be given opsumit.