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Study on Reversing Opioid-Induced Breathing Problems Using Naloxone and Nalmefene in Healthy Volunteers and Opioid Users

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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 certain medications on reversing breathing problems caused by opioids. The diseases being studied include opioid use disorder and the trial also involves healthy volunteers. The medications being tested are nalmefene hydrochloride, naloxone hydrochloride, fentanyl citrate, sufentanil, and ondansetron hydrochloride dihydrate. These medications are used in different forms such as injections and nasal sprays.

The purpose of the study is to understand how these medications can help reverse the breathing difficulties that opioids can cause. Participants will receive either the medication or a placebo, and their breathing will be monitored to see how well the medications work. The study will involve both people who are new to opioids and those who have been using them for a long time.

Throughout the study, participants will receive the medications through injections or nasal sprays, and their breathing will be closely observed. The study aims to gather information on how quickly and effectively these medications can reverse the effects of opioids on breathing. This research is important for improving treatments for people who experience breathing 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 required to sign an informed consent form. This form confirms your understanding of the study and your agreement to participate. It is important to comply with the study requirements and restrictions outlined in the form.

  2. Step 2

    Initial assessment

    An initial assessment will be conducted to ensure eligibility. This includes a review of your medical and surgical history, a physical examination, and tests such as vital signs, a 12-lead ECG, and blood tests. For women of childbearing potential, a pregnancy test will be conducted.

  3. Step 3

    Medication administration

    During the trial, you will receive medications intravenously (through a vein) or intranasally (through the nose). The medications include fentanyl, sufentanil, naloxone, and nalmefene. The specific dosage and frequency will be determined by the study protocol and administered by healthcare professionals.

  4. Step 4

    Monitoring and data collection

    Throughout the study, your ventilation (breathing) will be closely monitored. Blood samples will be taken to measure the concentration of the medications in your system. This data will help in understanding how the medications affect your breathing and how quickly they work.

  5. Step 5

    End of participation

    At the end of your participation in the study, a final assessment will be conducted. This may include a physical examination and additional tests to ensure your well-being. You will be informed about any follow-up requirements or additional care needed after the study.

Who can join the trial?

16 criteria

  • Healthy Volunteers:
  • Must sign the informed consent form and be able to follow the study requirements.
  • Must be male or female, aged 18 to 70 years.
  • Women who can have children must have a negative pregnancy test before joining and agree to use reliable birth control from the start of the study until at least 1 month after the last dose of the study drug.
  • Must have a Body Mass Index (BMI) between 18 and 30 kg/m2. BMI is a measure of body fat based on height and weight.
  • Must be considered healthy by the study doctor, based on medical history, physical exam, vital signs, and lab tests. This includes having normal kidney function and liver enzyme levels, and negative tests for HIV and hepatitis B or C.
  • Must have no history of substance use disorder.
  • Chronic Opioid Users:
  • Must sign the consent form and be able to follow the study requirements.
  • Must be male or female, aged 18 to 70 years.
  • Women who can have children must have a negative pregnancy test before joining and agree to use reliable birth control from the start of the study until at least 3 months after the last dose of the study drug.
  • Must have a Body Mass Index (BMI) between 18 and 32 kg/m2.
  • Must be taking prescription opioids at daily doses equal to or greater than 60 mg of oral morphine equivalents. Opioid tolerance means the body is used to opioids and requires more to feel the same effect.
  • Must be considered stable by the study doctor, based on medical history, physical exam, vital signs, heart test (ECG), and blood tests.
  • Must have a positive opioid urine drug screening, which means opioids are detected in the urine.
  • Must have a positive naloxone challenge, which is a test to see how the body responds to naloxone, a medication used to reverse opioid effects.

Who cannot join the trial?

2 criteria

  • Patients who are not healthy volunteers cannot participate. This means the study is only for people who do not have any medical conditions.
  • Patients with opioid use disorder cannot participate. This refers to a condition where a person has a problematic pattern of opioid use that causes significant impairment or distress.
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Investigated drugs

  • Fentanyl

    is a powerful medication used to relieve severe pain. In this study, it is being used to understand how it affects breathing. Researchers are looking at how the body processes fentanyl and how it impacts the ability to breathe, especially when used in people who are not used to taking opioids and those who use them regularly.

  • Sufentanil

    is another strong pain-relieving medication similar to fentanyl. It is being studied to see how it affects breathing and how the body handles the medication. This helps researchers understand its impact on people who are new to opioids and those who have been using them for a long time.

  • Naloxone

    is a medication used to quickly reverse the effects of opioids, especially in cases where breathing has slowed or stopped. In this study, it is being tested in both nasal spray and injection forms to see how well it can help restore normal breathing in people affected by opioids like fentanyl and sufentanil.

  • Nalmefene

    is another medication used to counteract the effects of opioids. It is similar to naloxone but may work for a longer period. In this study, it is being used to see how effectively it can reverse breathing problems caused by opioids, helping to restore normal breathing in affected individuals.

What is already known about the treatment

  • Fentanyl

    Fentanyl is administered intravenously, meaning it is injected directly into the bloodstream. It is currently used in medical settings to manage severe pain and is well-documented in medical literature. The main therapeutic indication for fentanyl is pain relief, particularly in patients who are opioid-naïve or chronic opioid users. At the molecular level, fentanyl works by binding to opioid receptors in the brain, which reduces the perception of pain. It is classified as an opioid analgesic.

  • Sufentanil

    Sufentanil is also administered intravenously and is used in medical practice for pain management, especially during surgery or in intensive care. It is recognized in medical literature for its potency and effectiveness. The primary therapeutic use of sufentanil is to provide pain relief in controlled medical environments. Sufentanil acts by binding to opioid receptors in the central nervous system, altering the way the brain and body perceive pain. It is classified as an opioid analgesic.

  • Naloxone

    Naloxone can be administered intranasally, as a nasal spray, or intravenously, directly into the bloodstream. It is widely used in medicine to reverse the effects of opioid overdose, particularly respiratory depression. Naloxone works by quickly binding to opioid receptors, blocking the effects of opioids like fentanyl and sufentanil. It is classified as an opioid antagonist.

  • Nalmefene

    Nalmefene is administered intravenously and is used in medical settings to counteract the effects of opioid overdose, similar to naloxone. It is known in medical literature for its ability to reverse respiratory depression caused by opioids. Nalmefene acts by binding to opioid receptors, preventing opioids from exerting their effects. It is classified as an opioid antagonist.

Investigated diseases

Opioid Use Disorder – Opioid Use Disorder is a condition characterized by a problematic pattern of opioid use that leads to significant impairment or distress. It involves a strong desire to take opioids, difficulties in controlling their use, and continued use despite harmful consequences. The disorder often progresses with increased tolerance, meaning more of the drug is needed to achieve the same effect. Individuals may experience withdrawal symptoms when not using opioids. Over time, the disorder can lead to significant physical and psychological issues. The progression can vary widely among individuals, influenced by factors such as the type of opioid used and personal health conditions.
Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2024-518041-16-00Estimated enrolment24 patientsSponsorLeids Universitair Medisch Centrum (LUMC)

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