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Study on the Effects of Naldemedine and Tramadol on Opioid-Induced Bowel Dysfunction in Patients Using Opioids

Verified siteRegistered drugNo placebo
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What is this trial about?

A plain-language summary of the goals, design and what participants do

This clinical trial is focused on studying the effects of a medication called naldemedine on a condition known as opioid-induced bowel dysfunction. This condition can occur when people take opioids, like tramadol, which are strong pain-relieving medications. Opioids can sometimes cause problems with bowel movements, leading to discomfort and constipation. The trial will also involve the use of a placebo, which is a substance with no active medication, to compare the effects.

The purpose of the study is to explore how naldemedine can help manage the bowel issues caused by opioids. Participants in the study will take either naldemedine or a placebo while their bowel function is monitored. This will include looking at how quickly food moves through the digestive system, the patterns of movement in the intestines, and the volume of the colon. These observations will help researchers understand how naldemedine affects the digestive system when opioids are used.

The study will take place over a period of time, during which participants will be asked to take the medication and undergo various assessments. These assessments will include methods like MRI to look at the colon and other tests to measure bowel movement and function. The goal is to gather information that could lead to better treatments for people experiencing bowel problems due to opioid use.

The research process

The trial runs in 5 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Joining the study

    Upon joining the study, you will be assessed by a study-affiliated medical doctor to confirm that you are healthy. You will need to sign an informed consent form, which indicates that you understand the study and agree to participate.

    You must be able to read and understand Danish, be male, and of Northern European descent. You should be between 20 and 40 years of age and have no or low anxiety as assessed by a specific score range.

  2. Step 2

    Medication administration

    You will be given two types of tablets to take orally. The first is Rizmoic, which contains 200 micrograms of naldemedine. The second is Tramadol HCl Retard Mylan, which contains 100 mg of tramadol hydrochloride. These medications are designed to be taken as film-coated and prolonged-release tablets, respectively.

    The exact dosage, frequency, and duration of administration will be provided to you by the study team. It is important to follow these instructions carefully.

  3. Step 3

    Monitoring and assessments

    Throughout the study, your gastrointestinal transit and motility patterns will be monitored. This involves measuring how quickly food moves through your digestive system and how your intestines contract.

    You will also undergo assessments to evaluate any symptoms of constipation and to check for signs of opioid withdrawal. These assessments will include subjective questionnaires and diagnostic evaluations.

  4. Step 4

    Imaging and measurements

    You will have imaging tests, such as MRI scans, to assess the volume and water content in your colon. These tests help to understand how the medications affect your digestive system.

    Additional measurements will be taken to evaluate pressures and indices related to bowel movements using a device called Fecobionics.

  5. Step 5

    Completion of the study

    The study is expected to end by June 30, 2025. Upon completion, you will have a final assessment to ensure your health and well-being.

    The results of the study will contribute to understanding the effects of naldemedine on opioid-induced bowel dysfunction.

Who can join the trial?

9 criteria

  • Healthy: You must be in good health, as determined by a doctor involved in the study.
  • Signed informed consent: You need to sign a document that shows you understand the study and agree to participate.
  • Able to read and understand Danish: You must be able to read and understand the Danish language.
  • Male: Only males can participate in this study to avoid the influence of menstrual cycles.
  • Northern European descent: You should be of Northern European background to reduce differences in how the body processes the drug.
  • Understanding of the study: The researcher must believe that you understand the study details, will follow the study rules, and are likely to complete the study.
  • Opioid naïve: You should not have used opioids before. Opioids are a type of pain medication.
  • Between 20 and 40 years of age: You must be between 20 and 40 years old.
  • STAI score between 20-37: You need to have a score between 20 and 37 on the State-Trait Anxiety Inventory (STAI), which means you have no or low anxiety.

Who cannot join the trial?

3 criteria

  • Patients who are not experiencing opioid induced bowel dysfunction cannot participate. This condition occurs when certain pain medications, like opioids, cause problems with bowel movements.
  • Only male patients are eligible to participate in this study.
  • Patients who are part of a vulnerable population, such as those who cannot make decisions for themselves, are not eligible.
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Verified sites

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  • Verified

    Mech Sense

    DenmarkAalborg, Denmark

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Investigated drugs

  • Naldemedine

    is a medication used in this clinical trial to help manage bowel problems caused by taking opioids, like tramadol. Opioids can often lead to constipation and other bowel issues. Naldemedine works by blocking the effects of opioids in the gut, which helps to keep the bowels moving normally without affecting the pain relief provided by the opioids.

  • Tramadol

    is an opioid pain medication used in this trial. It is commonly prescribed to relieve moderate to severe pain. However, like many opioids, tramadol can cause side effects such as constipation. This trial is exploring how naldemedine can help reduce these bowel-related side effects while patients are taking tramadol for pain relief.

What is already known about the treatment

Naldemedine – Naldemedine is taken orally and is used to help manage bowel problems caused by opioid pain medications, like tramadol. It is currently being studied for its effectiveness in treating these issues, which are common in people taking opioids for pain relief. Naldemedine works by blocking the effects of opioids in the gut without affecting pain relief, helping to restore normal bowel function. It belongs to a class of drugs known as peripherally acting mu-opioid receptor antagonists.

Investigated diseases

Opioid-induced bowel dysfunction – This condition occurs when the use of opioid medications, such as tramadol, affects the normal functioning of the bowel. It primarily manifests as constipation, but can also include symptoms like bloating, abdominal pain, and a feeling of incomplete evacuation. Opioids slow down the movement of the gastrointestinal tract, leading to increased water absorption from the stool, making it harder and more difficult to pass. The condition can also alter the motility patterns of the intestines, affecting the overall transit time of food through the digestive system. Additionally, it may impact the secretion of fluids in the intestines and change the volume of the colon. These changes can lead to discomfort and a significant impact on quality of life.
Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IITrial ID2023-507744-36-00Estimated enrolment20 patientsSponsorAalborg University Hospital

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This service is not affiliated with the European Commission, the EMA, or the official CTIS system. Most information comes from publicly available international clinical-trial registries, supplemented by data from academic sites, national regulators and commercial sponsors. On this site, “treatment” and “therapy” mean a medicine being tested in a clinical trial. Its safety and effectiveness in the use being studied are not yet confirmed, some participants may receive a placebo or a comparator, and taking part does not guarantee a health benefit. The doctor at the research site decides who can take part. This site provides information, not medical advice. Certain content and visual elements on this website have been generated or enhanced using artificial intelligence (AI).