Safety and Efficacy of Nimesulide/Paracetamol Fixed-dose Combination in Acute Pain (SAFE Study)

Abstract

Background: Nimesulide shows preferential inhibition for the cyclooxygenase-2 (COX-2) enzyme, which blocks the formation of prostaglandins critical in pain and inflammatory pathways. Few studies in the past have reported rare and unpredictable hepatic effects with nimesulide. The present study aimed to evaluate the efficacy and safety of nimesulide/paracetamol (100 mg + 325 mg) fixed-dose combination twice a day for 2 weeks in the management of acute pain in Indian population. Materials and methods: This was a multicenter study, performed on 500 patients, by 24 experienced physicians across India. The primary outcome assessed clinical safety at 2 weeks for mild/serious adverse effects (AEs), change in liver function tests (LFTs), serum bilirubin and alkaline phosphatase levels. The secondary outcomes assessed the clinical effectiveness in reduction of pain at rest and at movement. Results: Analysis of LFT at 2 weeks showed a slight increase (mean change) in the aspartate transaminase {-0.73 [95% confidence interval (CI) -1.54, 0.09; p = 0.081]}, alanine transaminase [-1.73 (95% CI -2.82, -0.64; p = 0.002)], serum bilirubin [-0.02 (95% CI -0.04, -0.001; p = 0.018)] and alkaline phosphatase levels [-1.92 (95% CI -5.84, 2; p = 0.336), not exceeding the normal range. Only one in 500 patients reported AEs. The numerical rating scale (NRS) scores for intensity of pain at rest and at movement at 2 weeks, ≤7 days and >7 days were 68.38%, 68.44% and 68.39%; and 65.43%, 64.60% and 66.02%, respectively. An improvement of 96.6% was observed in patient global assessment scale (GAS) and 97.2% in physician GAS. Conclusion: Nimesulide/paracetamol combination was safe, effective and well-tolerated in acute pain conditions and did not lead to clinically significant changes in liver parameters indicating hepatic safety.