An open-label, pilot study to examine the pharmacokinetics, efficacy and safety of Methylnaltrexone Bromide in paediatric patients with opioid-induced constipation who have failed standard aperient treatment.

This study tests a medication called methylnaltrexone bromide in children who are constipated due to opioid pain medications and haven't responded to standard treatments. Researchers want to understand how the drug works in young patients' bodies and whether it safely helps relieve constipation caused by long-term opioid use.