Hyoscyamine as a pharmacological adjunct in colonoscopy: A randomized, double blinded, placebo-controlled trial

OBJECTIVE: Investigators have assessed the utility of antispasmodic agents in colonoscopy, with conflicting results. The aim of this study is to deter mine the effects of premedication with hyoscyamine, an anticholinergic anti spasmodic, on outcomes in colonoscopy. METHODS: A total of 165 patients undergoing elective colonoscopy were rando mized in a double blinded fashion to one of three arms: intravenous hyoscya mine (0.25 mg), oral hyoscyamine (0.25 mg), or placebo, administered 20-40 min before colonoscopy. Primary outcome measures included insertion time to cecum, patient's assessment of pain, and physician assessment of spasm. Se condary outcome measures included amount of analgesic medications used, tot al procedure time, amount and type of pathology visualized, and physician a ssessment of patient's pain. RESULTS: Bivariate analysis showed no difference, between the three groups in insertion time (13.8 min, 14.8 min, and 13.8 min for placebo, intravenou s hyoscyamine, and oral hyocyamine, respectively), analgesic medication nec essary, or any other primary or secondary outcome variable. Multivariate an alysis controlling for potential confounders also failed to demonstrate any differences between the groups. Women had higher procedure duration and an algesic requirement, and reported more pain than did men. CONCLUSIONS: This randomized, double blinded, placebo-controlled trial did not demonstrate efficacy of either intravenous or oral hyoscyamine as a pre medication for colonoscopy. (C) 1999 by Am. Cell. of Gastroenterology.