Studies of gallbladder contraction using intramuscular sincalide.

Intramuscular sincalide (the carboxy terminal octapeptide of cholecystokinin) was evaluated as an agent for producing gallbladder contraction. Following oral cholecystography 35 patients received intramuscular sincalide in one of two dosages, 18 patients received intravenous sincalide, and six patients were given intramuscular placebo. Generalized symptoms, often similar to those noted clinically, were more common following intravenous injection of sincalide; gallbladder contraction was greater following intramuscular injection. Both of these findings may be related to lower but more sustained blood levels of sincalide following intramuscular administration. Intramuscular sincalide may be useful for further studies of the value of cholecystokinin cholecystography.