Ktin is a preparation of Ketotifen, which has anti-allergic properties and is effective in preventing asthmatic attacks. Ketotifen is a potent antihistamine, which exhibits strong H₁ receptor-blocking activity. In addition, it has been shown to possess anti-anaphylactic properties. Ktin exerts sustained inhibitory effect on histamine reactions, which can be clearly dissociated from its anti-anaphylactic properties. Also, it stabilizes mast cells & basophils and inhibits PAF (Platelet Activating Factor). The prophylactic activity of Ktin may take several weeks to become fully established.