Methylnaltrexone use in a seventeen-month-old female with progressive cancer and rectal prolapse.

BACKGROUND: Opioid-induced constipation is commonly seen in pediatrics, especially at the end of life. As patients clinically decline, constipation often leads to increased pain and distress, while its enteral treatment becomes more challenging.
METHOD: There is little information about the safety and use of methylnaltrexone in children. We present the case of a 17-month-old girl with progressive leukemia who was at the end of her life and whose severe opioid-induced constipation and rectal prolapse was successfully treated with the μ-opioid-receptor antagonist methylnaltrexone. We selected a lower dose based on our lack of experience with methylnaltrexone in this age group and concern for potential complications given her rectal prolapse. DISCUSSION: Opioid-induced constipation, abdominal distention, and rectal prolapse caused our patient's most distressing symptoms, even in the context of advanced cancer. A single dose of subcutaneous methylnaltrexone (0.12 mg/kg) resolved her constipation and rectal prolapse within one hour. Although evidence is limited, the drug has successfully been used in pediatric patients with no reported side effects to date. We recommend its use earlier in the course of severe opioid-induced constipation in children unable to tolerate an oral laxation regimen. Prospective research is needed to establish the parameters for use of this effective agent in children who cannot tolerate other regimens.