Oral nefopam and aspirin.

Analgesia through nefopam (30 mg, 60 mg, 90 mg), aspirin (325 mg, 650 mg), and placebo were compared in 122 hospitalized patients with moderate to severe postoperative, fracture, or other somatic pain. A double-blind noncrossover study design was used, and patients were evaluated for pain intensity and pain relief over a 6-hr period. Based on sum of pain intensity differences (SPID) scores, treatment effects were consistent and indicative of good dose response to both active medications. Pain relief scores were more variable but were generally in accordance with SPID values. Time-effect curves were similar. Estimated relative potency of nefopam to aspirin was 10.4 with a 95% confidence interval of 6.3 to 20.8 for SPID, indicating that the analgesic potency of nefopam, 60 mg, was equivalent to that of aspirin, 650 mg. Side effects were minimal.