The use of topical opioids for systemic pain management

Alternative routes to oral opioid administration in palliative care: a review and clinical summary

OBJECTIVE

A major goal of palliative care is to provide comfort, and pain is one of the most common causes of treatable suffering in patients with advanced disease. Opioids are indispensable for pain management in palliative care and can usually be provided by the oral route, which is safe, effective, and of lowest cost in most cases. As patients near the end of life, however, the need for alternate routes of medication increases with up to 70% of patients requiring a nonoral route for opioid administration. In order to optimize patient care, it is imperative that clinicians understand existing available options of opioid administration and their respective advantages and disadvantages.

METHODS

We performed a literature review to describe the most commonly used and available routes that can substitute for oral opioid therapy and to provide a summary of factors affecting choice of opioid for use in palliative care in terms of benefits, indications, cautions, and general considerations.

RESULTS

Clinical circumstances will largely dictate appropriateness of the route selected. When the oral route is unavailable, subcutaneous, intravenous, and enteral routes are preferred in the palliative care population. The evidence supporting sublingual, buccal, rectal, and transdermal gel routes is mixed.

CONCLUSIONS

This review is not designed to be a critical appraisal of the quality of current evidence; rather, it is a summation of that evidence and of current clinical practices regarding alternate routes of opioid administration. In doing so, the overarching goal of this review is to support more informed clinical decision making.

Topical morphine gel in the treatment of painful leg ulcers, a double-blind, placebo-controlled clinical trial: a pilot study

Chronic painful wounds, a major health problem, have a detrimental impact on the quality of life due to associated pain. Some clinical reports have suggested that local administration of morphine could be beneficial. The aim of this study was to evaluate the analgesic effect of topically applied morphine on chronic painful leg ulcers. Twenty-one patients were randomly assigned to receive either morphine or placebo in a randomised, placebo-controlled, crossover pilot study. Each patient was treated four times in total. Pain was measured by the visual analogue score (VAS) before application of gel, directly after and after 2, 6, 12 and 24 hours. Although an overall, clinically relevant, reduction of pain was observed upon treatment with morphine, the difference was not statistically significant. Morphine reduced pain scores more than placebo on treatment occasions 1 and 2. The difference was statistically significant only 2 hours after dressing on the first treatment occasion. Thus, our study did not demonstrate a consistent and globally significant difference in nociception in patients treated with morphine. However, the relatively small number of patients included in our study and other methodological limitations makes it difficult for us to draw general conclusions regarding efficacy of topically applied morphine as an effective treatment for some painful ulcers. Further studies are warranted to evaluate the value of topically applied morphine in the treatment of patients with chronic painful leg ulcers.