About Ketotifen Second Generation H1 Antagonist, Mast Cell Stabilizer, Antihistamine. Mechanism of Action of Ketotifen It is a mast cell stabilizer. This inhibit the development of airway hyper reactivity (associated with activation of platelets by PAF (Platelet Activating Factor) or caused by neural activation following the use of sympathomimetic drugs or the exposure to allergen) by suppressing the priming of eosinophils by human recombinant cytokines and thereby suppression of the influx of eosinophils into inflammatory site. In addition, Ketotifen is a potent antiallergic substance possessing a powerful and sustained noncompetitive histamine (H 1) blocking property. Indications for Ketotifen 1. Rhinitis 2. Conjunctivitis 3. Prophylaxis for bronchial asthma Interactions for Ketotifen Sedatives, Hypnotics & Alcohol: May potentiate the effects of these agents, leading to CNS depression. Oral antidiabetics: Avoid as fall in thrombocyte count reported.