CYCLIZINE hydrochloride (Marezine, Compound 47-83 [N-benzhydryl-N'-methylpiperazine dihydrochloride] ) is a new drug which was originally introduced because of its antihistaminic activity, its potency in this regard being comparable to that of diphenhydramine (Benadryl). It is a water soluble, bittertasting, white crystalline solid having the following formula (C6H5)?CHN^ Z ^>-CH3'2HCI Experimental studies in animals and man reveal it to be a relatively nontoxic compound. In addition to its antihistaminic properties, cyclizine is a moderately active local anesthetic and also displays atropine-like antispasmodic effects upon intestinal smooth muscle.1Chinn and his associates,* who have clinically tested numerous compounds of varying pharmacologie natures for their effectiveness in the prophylaxis of seasickness, found that both cyclizine and chlorcyclizine (Perazil) hydrochloride offered significant protection against motion sickness. Because of such studies and because of the pharmacologie relationships to compounds now being utilized for the symptomatic relief of dizziness and