The effect of papaverine on the contraction of the human gallbladder.

In a double-blind study, 40 mg of papaverine (Group I) or the same amount of placebo (1.0 ml of physiological saline, Group II)was injected intravenously in 19 patients to study the effect of papaverine on the contractility of the gallbladder in connection with routine oral cholecystography. In both groups a standard contraction meal (200 ml of cream) caused a significant contraction of the gallbladder (at 30 minutes). Thereafter, intravenously administered papaverine significantly inhibited further contraction caused by the fatty meal, but no significant dilatation was observed. This difference between the two groups lasted throughout the whole study period to 60 minutes after the drug administration. This time period mainly consisted of the distributional alpha-phase of the drug concentrations determined by gas chromatography in the serum. Because no dilation effect on the gallbladder was found, the clinical spasmolytic response to papaverine during an acute attack of pain in a patient with gallstones seems to be questionable.