Determination of efficacy and toxicity of diclofenac microemulsion formulation for musculoskeletal pain: an observational study.

OBJECTIVE: Musculoskeletal pain is often caused by injury to the bones, muscles, tendons, ligaments or nerves. Symptoms can be localized or generalized. Mild-moderate symptoms are treated with topical/oral over the counter drugs. Microemulsion delivery formulations are thermodynamically stable, have superior bioavailability and better penetration of lipophilic and hydrophilic drug into the dermis. A prospective observational study in patients: 18 years or older, with mild-moderate musculoskeletal pain; with severe pain without adequate pain control; with severe pain and could not tolerate oral agents; with renal impairment were invited to try diclofenac 2% in microemulsion foam. They were followed up at 2 and 4 weeks. A 50% reduction on a visual analog pain scale was considered success. Adverse events were defined as irritation, gastrointestinal upset/bleed, rectal bleed, and hematemesis. The objective was to determine the efficacy and toxicity of diclofenac 2% in microemulsion foam. RESULTS: Thirteen consecutive patients with musculoskeletal pain consented to participate. Two patients were lost to follow up. Two of the 11 patients reported minimal improvement, while nine patients reported minimum 50% reduction. No adverse effects were reported. Diclofenac 2% in microemulsion foam is effective in the treatment of mild to moderate musculoskeletal pain and well tolerated.