An antiemetic drug that also decreases acid secretion due to its action on H1 receptors is
promethazine is a first generation H1 antihidtaminic drug.it is inficated fir treatment of allergic reactions.because of its anticholinergic action and abikity to cross blood brain barrier it can be used as an antiemetic and an anti parkinsonian drug . acid secretion is reduced mainly by H2 blocking drugs like ranitidine but even H1 anti histamainics can also reduce secretion at high doses .
promethazine
domperidone
metaclopromide
ondansetron
Gastrointestinal tract