A multicenter analgesic study using single doses of placebo, propoxyphene and acetaminophen.

Six studies were conducted using identical protocols. The design involved single oral doses of placebo, propoxyphene, acetaminophen and a combination of the two drugs. Postpartum patients with either postepisiotomy or uterine cramp pain participated. Both efficacy and adverse reports were evaluated. The differences among medications were consistently less than one standard deviation from the mean for the studies indicating a lack of sensitivity to drug effects. In order of increasing effectiveness based on the pooled data, the medications were placebo, propoxyphene, acetaminophen, and the combination.