Effect of small doses of somatostatin analog, octreotide, on gallbladder contractility in normal Chinese adults.

The acute effects of single different doses of the somatostatin analog octreotide on the contractility of the gallbladder stimulated by fatty meal were studied in six healthy Chinese volunteers. Gallbladder contraction after a fatty meal was significantly suppressed by octreotide at doses of 50, 25, 12.5, and 5 micrograms. Mean duration of suppression lasted for more than 10 hr at doses of 25 and 50 micrograms, after which the gallbladder contractility was restored at 24 hr in three and four, respectively, of the six subjects. The percentage of relative gallbladder contraction (PRGC) in all subjects receiving 12.5 and 5 micrograms octreotide returned to pretreatment values at 10 hr but had not returned to normal 6 hr after the injection of 5 micrograms octreotide. In summary, octreotide inhibits the contraction of the gallbladder even with a dose as low as 5 micrograms. It appears that it may not be possible to avoid gallbladder dysfunction during long-term octreotide therapy by decreasing the dose. Further studies including modalities to increase the contractility of the gallbladder are recommended.