Control of Nausea and Vomiting

Nausea and vomiting are distressing symptoms which denote irritation or abnormal stimulation of the vomiting center, which lies in the medulla oblongata. Etiological factors are diverse and may influence the emesis center directly or, perhaps more frequently, the chemoreceptor trigger zone, which lies more superficially in the medulla.1 Of the many drugs which have been advocated to prevent or control emesis, none has achieved such a universal acceptance in a short period as chlorpromazine. It has given clinical protection in apomorphineinduced vomiting,2in uremia,3in irradiation sickness,4in postoperative vomiting,5and in several miscellaneous conditions, including the vomiting of pregnancy.6Experimental evidence suggests that chlorpromazine exerts an action directly on the chemoreceptive trigger zone.7The only dissenting voice against the reliability of chlorpromazine in controlling nausea and vomiting has come from an experienced group who state it gave no significant protection in motion sickness.8 Before such a drug as chlorpromazine