Antiemetic action is produced through:
Mechanism of action of antiemetic drugs are: Anticholinergic e.g hyoscine H1 antihistaminics e.g promethazine,diphenyhydramine,cyclizine. 5-HT3 antagonists e.g ondansetrone,granisetron Prokinetics. 5HT4 agonists e.g cisapride. Motilin agonist e.g erythromycin. CTZ contains histamine dopamine,cholinergic,opioid and serotonin receptors.antiemetic acts by inhibiting the receptors at CTZ.( ref KDT 6/e p643)
Decreased CTZ stimulation
H1 agonistic action
D1 antagonistic action
Olfactory apparatus stimulation
Gastrointestinal tract