5-HT3 receptor antagonists do not alter spontaneous contraction of pregnant myometrium in vitro

• 5-HT3 receptor antagonists are used widely in pregnancy.
• The effects of 5-HT3 receptor antagonists on uterine contractility are unknown.
• Ondansetron, granisetron and tropisetron have no effect on myometrial contractility in vitro.

Background5-HT3 receptor antagonists are effective antiemetics for perioperative use. However, their effects on myometrial contractility remain unknown. We examined whether three different 5-HT3 receptor antagonists could affect the contraction of human myometrium.MethodsSamples of human myometrium were taken from parturients undergoing elective cesarean delivery. Effects of ondansetron, granisetron and tropisetron (over a range of 1–104 ng/mL) on spontaneous contraction (ratios of amplitude, interval, and duration of the contraction) were examined and compared to saline controls (n=6 for each agent).ResultsNone of the three 5-HT3 receptor antagonists significantly affected myometrial contraction.Conclusion5-HT3 receptor antagonists do not affect the contraction of myometrial strips isolated from term pregnant women.