Introduction and Aims: This randomised, double-blind, placebo-controlled study evaluated the safety and effectiveness of dermal iontophoretic administration of Dexamethasone Sodium Phosphate 0.4% Injection, USP versus placebo in patients with medial and lateral elbow epicondylitis.

Method: 199 patients with elbow epicondylitis received 40 mA-min of either active or placebo treatment on six occasions. Treatments were spaced one to three days apart and were completed within 15 days. Efficacy variables included patient and investigator global evaluation of improvement, patient and investigator pain evaluation, patient evaluation of symptoms, investigator disease severity assessment and investigator evaluation of tenderness. Baseline scores were compared with scores two days and one month after the sixth treatment.

Results: Dexamethasone produced a 23 mm improvement in patient visual analog scale ratings compared with 14 mm for placebo (p=0.012) at two days and 24 mm compared with 19 mm (p=0.249) at one month. More dexamethasone patients than placebo patients had a score of moderate or better on the investigator global improvement score (52% vs 33%, p=0.013) at two days. This was not significant at one month (54% vs 49%, p=0.650). Investigator pain scores and tenderness scores favoured dexamethasone over placebo (p=0.019 and p< 0.001, respectively) at two days. Patients completing six treatments in ≤10 days appeared to show better efficacy than patients completing treatments over a longer period of time.

Conclusion: Iontophoresis treatment was well tolerated by the majority of the patients and was effective in reducing symptoms of epicondylitis at short-term follow-up.