Iontophoretic administration of dexamethasone sodium phosphate for acute epicondylitis. A randomized, double-blinded, placebo-controlled study.

BACKGROUND A better treatment modality is needed to control the pain of medial or lateral epicondylitis (tennis elbow). HYPOTHESIS Dermal iontophoretic administration of dexamethasone sodium phosphate will be significantly more effective in controlling pain than a placebo in patients with medial or lateral elbow epicondylitis. STUDY DESIGN Randomized, double-blinded, placebo-controlled study. METHODS On six occasions, 1 to 3 days apart within 15 days, 199 patients with elbow epicondylitis received 40 mA-minutes of either active or placebo treatment. RESULTS Dexamethasone produced a significant 23-mm improvement on the 100-mm patient visual analog scale ratings, compared with 14 mm for placebo at 2 days and 24 mm compared with 19 mm at 1 month. More patients treated with dexamethasone than those treated with placebo scored moderate or better on the investigator's global improvement scale (52% versus 33%) at 2 days, but the difference was not significant at 1 month (54% versus 49%). Investigator-rated pain and tenderness scores favored dexamethasone over placebo at 2 days. Patients completing six treatments in 10 days or less had better results than those treated over a longer period. CONCLUSIONS Iontophoresis treatment was well tolerated by most patients and was effective in reducing symptoms of epicondylitis at short-term follow-up.