Study to determine the efficacy of topical morphine on painful chronic skin ulcers.

OBJECTIVE

To assess the efficacy of the topical application of morphine on painful chronic skin ulcers.

METHOD: A prospective bi-centric controlled double-blind randomised study was conducted involving 24 patients with painful chronic skin ulcers using topically applied morphine versus placebo. Ten milligrams of morphine hydrochloride with Intrasite Gel or Intrasite Gel with placebo were applied daily for five days. All patients were treated with a level II analgesic treatment. A numeric pain scale lower than 4/10 and no need for a 'rescue' treatment (morphine sulphate) indicated that the treatment was successful. Local and systemic tolerance of the treatments was analysed daily.

RESULTS

Twenty-four patients were included in the study, but only 18 started the protocol. Only 2/11 patients were completely relieved in the morphine group compared with 1/7 in the placebo group. Local and general tolerance of morphine was good. The peripheral efficacy of morphine is under discussion.

CONCLUSION

The results suggest that topical morphine cannot be an alternative to morphine administered by other routes (subcutaneously or orally) in painful chronic skin ulcers. Stimulation of peripheral morphine receptors by systemic morphine could explain the difference between these results and those of previous studies.