EFFECT OF ERYTHROMYCIN ON GASTRIC-EMPTYING IN HEALTHY-INDIVIDUALS ASSESSED BY RADIO-OPAQUE MARKERS AND PLASMA ACETAMINOPHEN LEVELS

We simultaneously recorded gastric emptying of radio-opaque markers (R OMs) and monitored serial changes in plasma acetaminophen (AAP) levels to demonstrate the relationship between the ROM and the AAP methods, and we investigated the effect of a single intravenous dose of erythro mycin (EM) on gastric emptying in healthy human subjects, After an ove rnight fast, subjects were randomized to receive either placebo or EM lactobionate (Abbott, North Chicago, IL, USA) 250mg intravenously in a single dose, given immediately before a standard meal. Subjects inges ted 1.59 of AAP and ROMs with the test meal. A supine plain abdominal radiograph was taken 1, 2, 3, and 6 h after ingestion of the test meal . Peripheral blood samples were obtained 0, 0.5, 1, 1.5, 2, 3, and 6 h after ingestion of the test meal. EM significantly accelerated gastri c emptying of ROMs. By 6 h, no markers remained in the stomach in any of the subjects in the placebo or EM groups. By 120 min, half of the R OMs had passed into the duodenum in 12.5% of subjects after placebo, w hereas EM injection resulted in gastric emptying of half of the ROMs i n all subjects. There was no difference in plasma AAP concentration be tween the placebo and EM groups. There were significant correlations b etween maximum plasma AAP concentration and gastric emptying of ROMs 1 20 min after ingestion (r = 0.546; P = 0.019), and between time of max imum plasma AAP concentration and gastric emptying of ROMs 120 min aft er ingestion (r = -0.568; P = 0.014). The time taken to reach the peak concentrations ranged from 30 to 90 min after ingestion, whereas most ROMs were emptied 120 min after ingestion. We conclude that the gastr ic emptying assessed by ROMs and by serial changes in plasma AAP level are good, non-invasive, clinically applicable tests. with a significa nt correlation between the two tests. A single intravenous dose of EM had a prokinetic effect on gastric emptying, assessed by ROMs, in heal thy human subjects.