Biliary colic as a model for assessing analgesic activity in man.

Acute pain from biliary colic is a model of pathological pain suitable for pharmacological investigations. It has been found useful for assaying analgesic effect of a narcotic-type agent (pentazocine) and a non-narcotic drug (indoprofen), both given intravenously in a single dose. Differences in pain intensity scores assessed on a five-point scale were taken as measurement of the pain-relieving effect. Distribution-free methods were used to estimate the potency ratio of the tested drugs. The analgesic potency of indoprofen based both on total and peak effect was roughly one-tenth that of pentazocine on a weight-for-weight basis. No adverse reactions were associated with indoprofen and a few were found after pentazocine.