Extent and time course of pain intensity upon treatment with a topical diclofenac sodium patch versus placebo in acute traumatic injury based on a validated end point: post hoc analysis of a randomized placebo-controlled trial.

Objective: To investigate the extent and time course of pain intensity upon treatment with a topical diclofenac patch compared with placebo in acute traumatic sport injury based on a validated and established end point.

Methods: Post hoc analysis of a randomized, placebo-controlled, double-blind, multicentre, 1-week study in 120 patients with traumatic blunt soft tissue injury. Visual analogue scale (VAS) scores (in millimetres) for pain on movement were analysed. The mean absolute VAS changes in pain intensity from baseline over the study course were calculated for the diclofenac patch formulation (active) and placebo; mean differences between active and placebo were assessed twice daily during the first 3 days after enrolment and then once daily up to day 7.

Results: The diclofenac patch was consistently superior to placebo in relieving pain. The mean differences compared with placebo were greatest on day 2 (23.6 - 30.6 mm, p < 0.0001) and day 3 (24.5 - 24.6 mm, p < 0.0001). Diminishing differences were observed over the study course.

Conclusion: The investigated diclofenac sodium patch provides clinically relevant pain relief in patients with acute traumatic injuries. Maximum effects versus placebo are detected at 2 - 3 days post-injury. This analysis may serve as useful information for the planning of clinical trials in acute traumatic injury.