Objective: A randomized study comparing efficacy and safety of a new 75 mg/1 ml formulation of injectable diclofenac sodium designed for intra-deltoid use with the conventional 75 mg/3 ml formulation given by the intra-gluteal route.
Design: This was an open-label, multicentric, randomized clinical trial.
Methods: A total of 250 adult patients with post-operative pain were randomized to receive either an injection diclofenac 75 mg/1 ml or diclofenac 75 mg/3 ml. Primary efficacy criteria were time to onset of analgesia and reduction in pain intensity. Severity of pain at site of injection and side effects were also evaluated.
Results: 232 patients completed the study. The mean times to onset of anal-gesia were comparable (16.17 ± 12.70 min in the diclofenac 75 mg/1 ml group and 19.16 ± 11.79 min in the diclofenac 75 mg/3 ml group). However, significantly more patients achieved analgesia in less than 5 min and had less pain at the site of injection with the 1 ml formulation. The need for rescue medication was also lower with the 1 ml formulation (2.5% vs. 9.82%). No side effects were reported. A significantly larger number of patients and physicians rated the efficacy and safety of injectable diclo-fenac 75 mg/1 ml as excellent.
Conclusion: Both formulations were effective and safe in the management of post-operative pain with a significantly lower need for rescue analgesia and less pain at site of injection with diclofenac 75 mg/1 ml formulation. The 1 ml formulation had an added advantage of intra-deltoid use. This would be specially helpful in obese/overweight patients with a thick subcutaneous pad of fat over the gluteal region.