An anti-emetic drug that also decreases acid secretion due to its action on H1 receptors is:

Ans. (A) Promethazine(Ref: Katzung 11/e p277)Promethazine is a first generation H1 -antihistaminic drug. It is indicated for treatment of allergic reactions. Because of its anticholinegic action and ability to cross blood brain barrier, it can be used as an antiemetic (particularly for prophylaxis of motion sickness) and as an anti-Parkinsonian drug (particularly in drug induced Parkinsonism).Acid secretion is reduced mainly by H2 -blocking drugs like ranitidine but even H1 -anti histaminics can also reduce acid secretion at high doses (due to lack of selectivity at such high dose).