A topically applied quaternary ammonium compound exhibits analgesic effects for orthopedic pain.

OBJECTIVE To investigate the effectiveness of a topically applied emulsion of an analgesic ammonium solution for the temporary treatment of pain associated with arthritis, tendinitis and bursitis. DESIGN 100 subjects in a single center, presenting with chronic pain associated with arthritis, tendinitis, or bursitis trialed against placebo in a double-blind cross-over protocol. MAIN OUTCOME MEASURES Measures of treatment success include reduction in pain, improvement in clinical and/or mechanical evaluations, and evaluation of local and systemic adverse effects. Analysis was conducted at two weeks, after one week's clearance, and again after two weeks. RESULTS For chronic neuralgia associated with arthritis, tendinitis, and bursitis, the test material had a positive effect at temporary pain reduction. Several subjects also recorded improvements in mechanical evaluations from baseline. Withdrawals due to systemic or local adverse reactions were minimal. CONCLUSION A topical emulsion of a strong ammonium solution utilizing quaternary ammonium, enhanced with certain penetration enhancers, is effective for temporary relief of pain associated with arthritis, tendinitis, and bursitis.