The story
From Mont(r)e(al) + -lukast (“leukotriene receptor antagonist”), named after the city of Montreal, where the drug was developed by Merck in 1991.
Etymology from Wiktionary, CC BY-SA 4.0.
montelukast
Today it means: A leukotriene antagonist (trademark Singulair) used orally in the form of its sodium salt C₃₅H₃₅ClNNaO₃S to treat asthma or to relieve the symptoms of seasonal allergic rhinitis. Full definition →