[Reduced postoperative opioid requirement with perioperative administration of naproxen. A randomized study in 86 patients with intravenous on-demand analgesia after orthopaedic surgery.].

In a double-blind, randomized, placebo-controlled study, 86 patients (44 verum, 42 placebo), scheduled for knee-joint arthrotomies or minor orthopaedic operations received either naproxen, a nonsteroidal antiinflammatory analgesic, or placebo orally in three doses: the first immediately before the operation and the others 6 h and 12 h after the first. The verum group received 1250 mg naproxen in total. Postoperative pain intensity was measured by the category splitting procedure. All patients were allowed to self-administer piritramide from a PCA (patient-controlled analgesia) pump (Prominjekt, Pharmacia, Sweden) in 2-mg boluses every 5 min during a 6-h period and subsequently every 15 min for another 18 h after surgery. The patients receiving verum had significantly (P<0.05) less pain immediately after surgery and used a significantly lower cumulated dose of piritramide during the first 24 h after operation (24 mg vs 44 mg;P<0.05) than placebo-treated subjects. There were no significant differences in the incidence of side-effects between the two groups. The intensity of typical side effects of opioids and antipyretic anti-inflammatory analgesics (nausea, vomiting, stomachache, headache, vertigo) was low and they were easily controlled in all cases. Lowering of respiratory frequency was not observed. Perioperative administration of the nonsteroidal anti-inflammatory analgesic naproxen results in better pain relief and significantly lower opioid requirements (by about 46%) after minor orthopaedic surgery.