Effects of midazolam on small bowel motility in humans

Background: Benzodiazepines are used as sedatives for some intestinal procedures and as hypnotics, and this is the reason for studying their effects on duodenojejunal motility. Methods: Antroduodenojejunal manometry was performed in 13 healthy volunteers on two different occasions, when placebo or midazolam were given intravenously (randomized, double-blind). A bolus dose of midazolam 0.03 mg/kg was followed by 0.015 mg/kg after 1.5, 3 and 4.5 h. After 5 h observation of interdigestive motility, the volunteers were given a test meal and recording continued for another hour. Twenty-eight motility variables were compared. Results: With midazolam the median motility index of phase III in the proximal duodenum was increased by 37% (P < 0.05), which was a consequence of both a longer duration (P < 0.01) and higher pressure amplitudes (P < 0.05), compared with placebo. A longer duration (9%) of phase III was also seen in the distal duodenum (P < 0.05). With midazolam the duration of the migrating motor complex was shortened by 27% (P < 0.05). No statistically significant difference was found for the number of episodes of phase III registered (P=0.09), or for the other 22 motility variables compared including the duodenal retroperistalsis in late phase III. Conclusion: Midazolam does affect some aspects of duodenal motility, especially in the proximal part, but phase III-related retroperistalsis is not affected.