Less sedating anti emetic used in motion sickness and vertigo

Meclizine and cyclizine are often used in preventing motion sickness and for short-term treatment of vertigo because they are less sedating than diphenhydra­mine and promethazine. Promethazine also causes antiemetic activity and is available as a suppository or for injection. Chlorphen­iramine and brompheniramine, which are less sedating than diphenhydramine and promethazine, are often used alone or in combination with decongestants for allergies and colds. Cyproheptadine has antiserotonin activiry and may be useful in treating patients with carcinoid tUmor, where it blocks the effects of seroto­nin and histamine on smooth muscle. Aztemizole, loratadine, and terfenadine are nonsedating antihista­mines that do not cross the blood-brain barrier.