Lecope is a combination medication containing levocetirizine and montelukast. Levocetirizine blocks H1 receptors competing with allergy-causing compound histamine, and montelukast is a leukotriene antagonist (another chemical messenger) and reduces inflammation.
The chemical formula of montelukast is C35H36CL NO3 S. and the levocetirizine chemical formula is C21H25CIN.2O3, indicating the presence of sulfur in montelukast.