[Double-blind study of the effect of cyclotropium bromide on the smooth musculature of the esophagus. Description of a test of spasmolytic action].

Esophageal manometry can be employed to quantify the effects of antispasmodics in human subjects. Because of this, the effects of intravenously administered ciclotropium bromide (CTB) or hyoscine N-butylbromide (HNB) on esophagus smooth muscles were tested by manometry against saline (placebo) in 10 healthy volunteers in a randomized double-blind study. Tolerance as well as efficacy of CTB and HNB were evaluated. CTB administered intravenously significantly reduced the peristalsis amplitude following dry and wet acts of swallowing for at least 90 min. HNB caused a similar reduction which lasted only for 10 min. No reduction was observed following placebo except for physiological fluctuations. This shows that intravenous CTB causes a long-lasting reduction of smooth muscle contractions following the act of swallowing. Following placebo the lower esophageal sphincter (LES) pressure was higher than baseline values during the entire 90 min measurement period. CTB administration resulted in a significant reduction of the LES pressure compared to placebo. After HNB administration there was an initial decrease of the LES pressure lasting 30 min which was followed by an increase. None of the 3 drugs affected systolic or diastolic blood pressure. The heart rate did not change following placebo. After HNB administration heart rate was elevated at 15 min but decreased thereafter and was significantly lower than the baseline value at 45 min and later. CTB caused a significant increase of the heart rate at all sampling times. This increase corresponds well with the side-effects reported by 7 of the 10 subjects.