About Cyclizine Piperazine derivative , First Generation histamine H1- antagonist, Antihistamine,Antiemetic. Mechanism of Action of Cyclizine Cyclizine produces Antiemetic action by its central action on Chemoreceptor trigger zone (CTZ). It decreases the sensitivity of Labyrinth apparatus which transmit stimuli to the CTZ and stimulates the vomiting center. Cyclizine produces antivertigo action by decreasing the excitability of middle ear labyrinth. It blocks the conduction in the middle ear vestibular path ways. Cyclizine is a potent H1 receptor antihistaminic agent. It has anticholinergic activity also