The influence of duodenally-delivered Shakuyakukanzoto (Shao Yao Gan Cao Tang) on duodenal peristalsis during endoscopic retrograde cholangiopancreatography: a randomised controlled trial

BACKGROUND: Anti-cholinergic agents may be used to inhibit duodenal peristalsis, but they may have adverse effects. Shakuyakukanzoto (Shao Yao Gan Cao Tang) has an anti-spasmodic effect and has been used before for oesophagogastroduodenoscopy and colonoscopy. This randomised clinical trial aimed to evaluate the inhibitory effect of Shakuyakukanzoto on duodenal peristalsis, and its usefulness when administered into the duodenum just before endoscopic retrograde cholangiopancreatography (ERCP). METHODS: Participants were recruited between June 2008 and December 2010. All were aged ≥18 years and provided written informed consent. Exclusion criteria were: acute pancreatitis, a history of ischemic heart disease, prostatic hypertrophy or glaucoma, and altered/postsurgical upper gastrointestinal anatomy. The recruited participants were randomly assigned to the Shakuyakukanzoto group and control group. Shakuyakukanzoto 100 mg/mL solution or placebo (warm water) was administered directly as a spray into the duodenum during endoscopy. Efficacy was evaluated by observing the extent of duodenal peristalsis and assessing the difficulty of cannulating the common bile duct, the required time (RT) from administration to inhibition of duodenal peristalsis and the stop duration time (DT, the duration for which peristalsis was inhibited). Side effects were evaluated by measuring serum potassium concentration after ERCP. RESULTS: Of 28 participants, 15 were assigned to the Shakuyakukanzoto group and 13 to the control group. Duodenal peristalsis was inhibited in eight of the 10 eligible participants (80.0%) in the Shakuyakukanzoto group and none (0%) of the nine eligible participants in the control group (P = 0.026). In the Shakuyakukanzoto group, mean RT (±standard deviation) was 76.0 ± 23.9 s and DT was 11.3 ± 4.2 min. No adverse effects were observed in the Shakuyakukanzoto group during or after ERCP. CONCLUSION: Duodenal peristalsis can be inhibited by spraying Shakuyakukanzoto solution directly into the duodenum. Trial registration UMIN Clinical Trials Registry (UMIN-CTR) UMIN000011469 ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13020-016-0125-6) contains supplementary material, which is available to authorized users.