Alarid Syrup is an antihistamine and mast cell stabilizer manufactured by Square Pharmaceuticals Ltd., Bangladesh. Each 5 ml of the syrup contains 1 mg of Ketotifen Fumarate, an active ingredient effective in treating allergic conditions such as bronchial asthma, allergic rhinitis, conjunctivitis, hay fever, and urticaria (hives). Ketotifen works by inhibiting the release of histamine and other inflammatory mediators from mast cells, thereby reducing allergic symptoms.