Six randomised placebo-controlled trials (n=1,371), one randomised active-controlled trial (n=190) and one open-label study (n=101) were included in the review, along with three additional reports on tolerability. Three of the placebo-controlled trials were double blind.
Diclofenac epolamine topical patch 1.3% was associated with improvements in acute pain associated with minor soft tissue injuries over seven to 14 days compared with placebo plaster and DDA topical gel. Spontaneous pain was reduced from baseline at seven days (visual analogue scale (VAS) score 26% to 88%) and at 14 days (VAS score 56% to 61%) (three studies) and resulted in significantly better pain relief on day seven (88% versus 74%, p<0.001, one study) and day 14 (56.5% versus 46.8%, p=0.001, one study) compared to placebo plaster and on day 14 compared to DDA topical gel (60.8% versus 40.8%, p<0.001, one study).
Median time to pain resolution was three days less with diclofenac patch compared to placebo (8.8 versus 12.4 days, p=0.009).
Adverse events were reported in five of the included studies. Incidence was low and equivalent for diclofenac patch and placebo. The most common adverse events were cutaneous application-site reactions (pruritus, rash and dermatitis) and gastrointestinal symptoms (nausea). Tolerability findings from the additional three reports were also reported.