A controlled evaluation of orally administered aspirin, dipyrone and placebo in patients with post-operative pain.

A double-blind controlled trial was carried out in 267 patients with moderate to severe pain following episiotomy to compare the pain relief provided over a 6-hour period by a single oral dose of 500 mg dipyrone, 500 mg aspirin or placebo. The results showed that dipyrone and aspirin were both significantly superior to placebo. Pain relief with dipyrone was already apparent at 30 minutes after drug intake, and was of significantly longer duration than that of aspirin. No side-effects were reported.