Utilization of methylnaltrexone (relistor) for opioid-induced constipation in an oncology hospital.

age insert states that methylnaltrexone “is indicated for the treatment of opioid-induced constipation in patients with advanced illness who are receiving palliative care, when response to laxative therapy has not been sufficient.”8 These details were included as a consequence of the clinical trials, which had been conducted in patients receiving opioid therapy, consisting of a median daily baseline dose of oral morphine 150 mg or its equivalent. The patients with opioidinduced constipation (fewer than three bowel movements in the preceding week or no bowel movement for two days) had incurable cancer or another terminal illness, were receiving only palliative care, and had been following a stable laxative regimen for at least three days before entry into the study. When methylnaltrexone was added to the formulary of our comprehensive tertiary cancer hospital (M.D. Anderson Cancer Center) in October 2008, discussions focused on whether to restrict its use to the Department of Palliative Care and Rehabilitation Medicine (the palliative care service) in order to avoid off-label uses. However, it was decided to add the drug to the formulary without restriction with a subsequent drug use evaluation (DUE) to determine whether there was adherence to the labeled indication. The importance of conducting a DUE is even more evident now, because of the FDA’s label update indicating potential safety concerns with methylnaltrexone.7