Ketotifen, a cycloheptothiophenone, exhibits potent antihistamine effects as a non-bronchodilating anti-asthma medication. By inhibiting histamine and other mast cell mediators, blocking histamine H1 receptors, and suppressing phosphodiesterase enzyme activity, it elevates cyclic adenosine monophosphate levels. Notably, it curbs platelet-activating factor effects. While not halting bronchial asthma attacks on its own, Ketotifen precludes their onset, diminishes duration and intensity, and occasionally eradicates them.