Efficacy of a single dose of a transdermal diclofenac patch as pre-emptive postoperative analgesia: a comparison with intramuscular diclofenac

Abstract Background: We compared the analgesic efficacy of a transdermal diclofenac patch 100 mg (NuPatch® 100, Zydus Cadila, Ahmedabad, India) and intramuscular diclofenac sodium 75 mg (Voveran®, Novartis, India) for postoperative analgesia, and the associated side-effects of the transdermal diclofenac patch. Method: Sixty participants in the study were randomly allocated to two groups of 30 each, by a computer-generated randomisation table. The anaesthetic procedure was standardised. A transdermal diclofenac patch 100 mg was applied to the participants in the study group at the beginning of the surgery. In the control group, 75 mg of diclofenac sodium was given intramuscularly half an hour before the end of surgery. Pain was assessed postoperatively at two-, six-, and 12-hour intervals using a visual analogue scale (VAS). An injection of tramadol 2 mg/kg was administered intramuscularly as rescue analgesia. The study ended when the patients asked for rescue analgesia, or when the VAS score was > 5. Results: The mean duration of analgesia in the control group was 7 hours 28 minutes, and in study group, it was 8 hours 6 minutes, which was comparable (p-value < 0.341). Conclusion: Intraoperative application of a single dose of 100 mg transdermal diclofenac patch is as effective as a single dose of intramuscular diclofenac (75 mg) for acute postoperative pain, without any significant side-effects.