Effect of aspirin on gallbladder motility in patients with gallstone disease. A randomized, double-blind, placebo-controlled trial of two dosage schedules.

Patients with gallstone disease have impaired gallbladder motility. Prostaglandins are thought to be important mediators of gallbladder hypomotility. We assessed the effect of aspirin, a prostaglandin inhibitor on gallbladder resting volume and ejection fraction according to a double-blind study protocol in 20 healthy volunteers and 30 patients with gallstone disease. Healthy volunteers had a higher ejection fraction compared to patients with gallstone disease (73.9 +/- 0.9% vs 60.4 +/- 1.0%, P < 0.05). Aspirin in a dose of 350 mg/day for two weeks did not alter gallbladder motility in the healthy volunteers. Thirty patients with gallstone disease were randomized into three treatment groups: group I (placebo), group II (aspirin 350 mg/day), and group III (aspirin 1400 mg/day). After two weeks of treatment, gallbladder ejection fraction was improved in group II (74.0 +/- 1.7% vs 62.0 +/- 1.7%, P < 0.01) and group III (69.8 +/- 3.8% vs 61.2 +/- 1.3%, P < 0.01) but not in group I (60.4 +/- 2.6% vs 59.0 +/- 1.9%, P = NS). The higher dose of aspirin did not induce a greater increase in gallbladder emptying. It is concluded that impaired gallbladder motility in patients with gallstone disease is corrected by short-term oral aspirin even in low dosage. This may be clinically useful in secondary prophylaxis after nonsurgical therapy for gallstone disease.