Diclofenac Patch for Treatment of Mild to Moderate Ankle Sprain

Inclusion Criteria: * 18 to 75 years of age * Has sustained a painful Grade 1 or 2 ankle sprain (Appendix H) no more than 48 hours prior to study entry * Presence of pain of at least 5, with a maximum of 9, on an 11-point Numerical Rating Scale (NRS) Exclusion Criteria: * Grade 3 ankle sprain or bilateral sprain (see Appendix H) * Previous injury to the same ankle within 3 months prior to current injury * Aspirin or short half-life NSAID use within 12 hours, or longer half-life NSAID use within 24 hours prior to study entry (Appendix B) * Opioid use within 24 hours prior to study entry * Topical treatment, other than ice packs, applied to the painful region since time of injury * A history of peptic ulcer disease within 1 year of study entry, any history of gastrointestinal bleeding or coagulation disorder * A history of, or evidence for, underlying disease in the injured ankle, such as osteoarthritis or gout * Clinically significant, poorly controlled pulmonary, gastrointestinal, hepatic, renal, endocrine, or cardiovascular disease * A history of hypersensitivity to diclofenac or diclofenac-containing products * A history of intolerance to acetaminophen (rescue medication in this trial) * A history of skin sensitivity to adhesives (e.g. adhesive tape) * Pregnant or breastfeeding women and women of child-bearing potential not using effective means of contraception