Diclofenac epolamine plus heparin plaster versus diclofenac epolamine plaster in mild to moderate ankle sprain: a randomized, double-blind, parallel-group, placebo-controlled, multicentre, phase III trial.

Background: In general sports, ankle sprain is the most frequently reported ankle injury and can cause chronic lateral ankle pain and tenderness. Treatment with NSAIDs is preferred, and several topical NSAID formulations are now available, helping to avoid the systemic adverse events typically associated with oral preparations.

Objective: To compare the efficacy and tolerability of a newly developed fixed-dose diclofenac epolamine (diclofenac hydroxyethylpyrrolidine, DHEP)/heparin plaster (Flectoparin® Tissugel) with that of a DHEP (Flector EP Tissugel®) or placebo plaster in the treatment of mild to moderate ankle sprain in adults.

Methods: This was a randomized, double-blind, parallel-group, placebo-controlled, multicentre, phase III study conducted in the emergency medical centres of hospitals or private clinics in Europe. Outpatients aged 18-65 years who had suffered an acute ankle sprain (O'Donoghue grade I or II in severity, with external lateral ligament involvement) within the previous 48 hours and had peri-malleolar oedema were eligible for inclusion. A total of 430 patients were randomized to receive a DHEP/heparin 1.3%/5600 IU (n = 142), DHEP 1.3% (n = 146) or placebo (n = 142) plaster, applied once daily to the injured ankle for a total of 7 days. The primary endpoint was the mean change from baseline in pain on movement on day 3, as measured by a visual analogue scale (VAS).

Results: The DHEP/heparin plaster was associated with a significantly (p = 0.002) greater mean reduction from baseline in pain on movement after 3 days of treatment than the DHEP plaster (-24.2 vs -18.8 mm VAS), with each active treatment providing significantly (p ≤ 0.005) greater pain relief than placebo (-13.7 mm VAS). Both DHEP/heparin and DHEP were also effective in relieving other measures of pain, with DHEP/heparin recipients experiencing significantly less daily pain while leaning on the injured limb than DHEP recipients (p < 0.001). In addition, oedema was reduced to a significantly greater extent with DHEP/heparin than with placebo (day 7 only; p = 0.012). The DHEP/heparin plaster and DHEP plaster were both well tolerated, with adverse event profiles similar to that of placebo. Local adverse events were infrequent and generally mild in severity and there were no systemic adverse effects.

Conclusion: The fixed-dose DHEP/heparin plaster is effective and has advantages over the DHEP plaster in relieving pain, and possibly also swelling, associated with mild to moderate acute ankle sprains with oedema in adults.