The effect of size and shape of tablets on their esophageal transit.

The esophageal transit times of small- and medium-sized barium sulfate tablets were measured using x-ray fluoroscopy in 50 patients after swallowing while in both erect and supine positions with a 15-mL drink, and the esophageal transit times of large round and oval barium sulfate tablets were similarly measured in 25 patients. When tablets were swallowed by subjects who were standing, no difference was found between the transit times of small and medium tablets, but large oval tablets had significantly shorter times than did large round tablets (P less than .04). The transit times of both small and medium tablets were significantly shorter than those of oval (P less than .05) and large round tablets (P less than .02). Retention of large oval and round tablets in the esophagus occurred in 20% of patients after swallowing while in the standing position. No medium-sized tablet was retained, but in 4% of patients, a small tablet remained in the esophagus. Tablets that were retained in the esophagus remained there for five minutes, when they were washed down by a further drink. When tablets were swallowed in the lying position, no significant differences in transit times were found between any of the four tablets. Retention of tablets within the esophagus occurred in over 60% of patients with all four tablets after ingestion while in the supine position. Tablets stuck mainly in the lower esophagus above the lower esophageal sphincter, but after swallowing in the standing position, a significant proportion (33% [P less than .01]) stuck in the upper esophagus.(ABSTRACT TRUNCATED AT 250 WORDS)