The effects of serotonin (5-HT3) receptor antagonists on gastric tachyarrhythmia and the symptoms of motion sickness.

BACKGROUND

The purpose of this study was to determine the effects of the serotonin (5-HT3) receptor-antagonist antiemetics ondansetron and granisetron on the development of gastric tachyarrhythmia, nausea, and other symptoms of motion sickness.

METHODS

In a double-blind, counterbalanced, repeated measures design, 12 motion sickness susceptible college students participated in 3 sessions with an intersession interval of 1 wk. Participants received either 8 mg of ondansetron, 2 mg of granisetron, or placebo 1 h before exposure to a rotating optokinetic drum. Electrogastrograms (EGGs) were recorded during a 6-min baseline period and a subsequent 16-min drum rotation period. Subjective symptoms of motion sickness (SSMS) were obtained every 3 min during drum rotation.

RESULTS

During drum rotation, gastric tachyarrhythmia increased significantly more during the placebo condition than during either of the serotonin (5-HT3) receptor antagonist conditions. However, maximum SSMS scores were not different among conditions.

CONCLUSIONS

The serotonin (5-HT3) receptor antagonists inhibited the development of tachyarrhythmia, but did not prevent the development of nausea and other symptoms of motion sickness. The antiemetics ondansetron and granisetron may act as gastric anti-dysrhythmics, but their ability to arrest the development of gastric tachyarrhythmia was not sufficient for the prevention of nausea.