An apomorphine-induced vomiting model for antiemetic studies in man.

Apomorphine-induced vomiting is often used for preclinical efficacy testing of putative antiemetics in normal volunteers. The usual technique of individual intravenous titration for finding the threshold emitic dose of apomorphine in each subject is slow and tedious. We used a uniform dose of 0.05 mg/kg apomorphine given subcutaneously to test the antiemetic action of metoclopramide and votracon in ten healthy, young male volunteers. All ten subjects vomited in response to this dose of apomorphine when pretreated with placebo. Pretreatment with metoclopramide prevented vomiting in all subjects, and votracon prevented vomiting in two. Apomorphine, 0.05 mg/kg, subcutaneously appears to be an appropriate challenge dose for testing compounds for antiemetic activity in normal human volunteers.