A single-dose-finding study of the antiemetic effect and associated plasma levels of MDL 72222 in patients receiving cisplatin.

A total of 25 patients (5 groups of 5) were given single i.v. doses of 5, 10, 20, 40 and 60 mg MDL 72,222 (a 5-HT3 receptor antagonist) at 15 minutes before the commencement of a 24-h cisplatin infusion (total dose, 120-200 mg) to determine the efficacy and safety of the former in the prevention of nausea and vomiting associated with such chemotherapy. All patients completed the study. The time to onset of vomiting was significantly correlated with dose. All patients vomited following doses of 5 and 10 mg (range, 1-6 episodes), with onset being noted at 5-8 h. At the 20-mg level, only one episode of vomiting was observed in 3/5 patients, with onset being observed at 18-22 h. Following doses of 40 and 60 mg, 3/10 patients did not vomit; in the remaining patients the number of episodes ranged from 1 to 6, but a significant increase occurred in the time to onset of symptoms. At the higher doses, nausea tended to be milder in nature both at onset and at the time of maximal severity. A similar dose-effect trend was seen in the time to onset of the maximal severity of nausea. The time to and requirement for escape medication was similarly extended at doses of greater than or equal to 20 mg MDL 72,222. Pain at the injection site in one patient was the only unwanted effect associated with MDL 72,222. The results suggest that the i.v. injection of 20 mg MDL 72,222 should be further explored in the control of nausea and vomiting associated with cisplatin administration.