Comparison of postpartum pain treatments using a sequential trial design: II. Naproxen versus paracetamol.

The efficacy of naproxen and paracetamol in relieving uterine cramps has been compared in a sequential trial. The treatments did not differ significantly in a two-sided test in 56 patients. A corresponding fixed sample test would have required 140 patients to obtain the same significance level and power. In addition to uterine pain, the effect on episiotomy pain was also estimated at the termination of the trial. Again, there seemed to be no difference between naproxen and paracetamol.