ABSTRACT
Almost 70% of patients with cancer-related pain requires an alternative route for opioid administration hours and months before death. Another review demonstrated that CSCI is effective and safe for use in terminal illness. Despite this observation, the authors concluded that the SC route is an effective method for the systemic administration of morphine. Long-term rectal administration of high-dose sustained-release morphine tablets is reported by Walsh and Tropiano. The results of the study of Hojsted et al. comparing the pharmacokinetics of hydrochloride morphine administered via rectal and colostomic routes demonstrated that the bioavailability via colostomy showed a very wide variation, but the mean value as compared to rectal administration was 43%. Therefore, it is recommended that initial dosing begin with the lowest dose and that when switching from one formulation to another, re-titration should be considered in a monitored setting.
