Overview

This study looks at how well a medicine called naldemedine works for people with cancer who become constipated while taking opioids. Opioids are medications prescribed to treat persistent or severe pain. Opioids can slow down the bowel and make it hard to pass stool. About 6 out of 10 people who use opioids have constipation. Laxatives such as lactulose or macrogol are described to help with this problem. If laxatives do not work, doctors may use special medicines called opioid blockers that act only in the gut. These medicines help relieve constipation without reducing pain relief. Naldemedine is one of these opioid blockers. It became available in the Netherlands in 2024 but is not yet widely used. The goal of this study is to learn how well naldemedine works in everyday care and how people feel while using it. Researchers will collect information on both medical results and participants' experiences.

Eligibility

Inclusion Criteria:

• Adult (≥18 years)
• A diagnosis of malignancy
• Daily use of opioids
• Use of laxatives
• Experiencing constipation, defined as a Bowel Function Index (BFI) score ≥30
• Able to complete a Dutch-language questionnaire
• Able to provide written informed consent

Exclusion Criteria:

• Use of other opioid antagonists in the last month
• Suspected (risk of) gastrointestinal perforation
• Participation in another study that may confound the results of this trial