Oral cisapride increases gallbladder volume in volunteers

It has been previously reported that intravenous application of cisapride leads to a contraction of the gallbladder. To evaluate this potential prokinetic effect cisapride was given to healthy subjects in the clinically relevant oral form. In a randomized double‐blinded placebo controlled design gallbladder volumes were monitored by ultrasound. Orally given single doses above 5 mg cisapride resulted in a significant increase of gallbladder volume reaching a maximum of 176.7 ± 10.0% at 90 min after ingestion of the 40 mg dose. This effect was observed over more than 3 h. Contraction after a standard meal was significantly impaired by 20 mg cisapride (minimal residual volumes 8.4 ± 2.3% vs. 18.7 ± 3.7%; P < 0.05). Refilling of the gallbladder started significantly earlier after cisapride ingestion. The underlying mechanisms of these observations being in contrast to the prokinetic effects cisapride generally exerts on the gastrointestinal tract are still unknown.