Fractionated dose cholecystography: a comparison between iopanoic acid and sodium ipodate.

Two randomised groups of 100 subjects each, undergoing oral cholecystography, were given either a 6 g fractionated dose of iopanoic acid (Telepaque) or sodium ipodate (Biloptin) to determine the relative merits of this dose schedule. Exclusions to the study were pregnancy and iodine sensitivity. Calculi or abnormal gallbladder opacification were present in 45% of subjects. Both agents were equally effective in demonstrating abnormalities, although bile duct visualisation was better using iopanoic acid (P less than 0.05). Of 46 subjects with abnormal cholecystograms subsequently undergoing surgery, all had the diagnosis confirmed. Side effects occurred in 63% of all subjects, being twice as common in those taking iopanoic acid (P less than 0.01). Sodium ipodate in a large fractionated dose is favoured because of the lower occurrence of side effects without loss of diagnostic accuracy.