A Phase 2 interventional study of Target-controlled naloxone-infusion and Placebo in Central Nervous System Sensitization, Pain and Hyperalgesia, sponsored by Rigshospitalet, Denmark. Completed at 1 site in Denmark. Open to male participants aged 18 Years to 65 Years. Per ClinicalTrials.gov, last updated 2024-02-22.
Sponsored by Rigshospitalet, Denmark · Phase 2, Interventional, and Basic science
Recent studies have focused on the role of endogenous opioids on central sensitization. Central sensitization is known to be impaired or altered in chronic pain conditions, as fibromyalgia or chronic tension headache.
Animal studies have shown reinstatement of mechanical hypersensitivity following naloxone administration after resolution of an injury. This suggests latent sensitization.
In the present study, investigators hypothesize that a high-dose target-controlled naloxone infusion (total dose: 3.25 mg/kg) can reinstate pain and hyperalgesia 6-8 weeks after a unilateral primary open groin hernia repair procedure. Investigators aim to show that latent sensitization is present in humans and is modulated by endogenous opioids.
10,054 studies on the registry are indexed under Pain; 1,649 are open to participants now.
This study's enrollment of 9 is below the median of 66 across 8,493 interventional studies indexed under Pain.
Browse Pain studies →Rigshospitalet, Denmark is the lead sponsor of 1,007 studies on the registry; 175 are open to participants now.
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Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
The anaesthetists’ scale of health before surgery: I is healthy, II has a mild illness that is under control, III a severe one, IV a severe illness that is a constant threat to life. V and VI are used for the critically ill and for organ donors.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ASA physical status
The anaesthetists’ scale of health before surgery: I is healthy, II has a mild illness that is under control, III a severe one, IV a severe illness that is a constant threat to life. V and VI are used for the critically ill and for organ donors.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Change in Pain Ratings (NRS) at the surgical site and at the mirror-site in the contralateral groin six to eight weeks after unilateral herniotomy following administration of placebo.
Drug: Placebo
Change in Pain Ratings (NRS) at the surgical site and at the mirror-site in the contralateral groin six to eight weeks after unilateral herniotomy following administration of naloxone.
Drug: Target-controlled naloxone-infusion
Summated pain intensity
Change in pain ratings (\[NRS,0-10\] pain at rest + pain during transition from supine to standing position + pain during pressure (100 kPa) at injury site), assessed 6-8 weeks after unilateral, primary, open groin hernia repair following administration of naloxone/placebo.
Time frame: 1st session: 6-8 weeks after surgery; 2nd session: one week later
Secondary hyperalgesia/allodynia
Change in secondary hyperalgesia area/allodynia at surgical site and at the mirror-site in the contralateral groin assessed 6-8 weeks after unilateral, primary, open groin hernia repair following administration of naloxone/placebo.
Time frame: 1st session: 6-8 weeks after surgery; 2nd session: one week later
Pressure pain thresholds
Change in pressure pain thresholds at surgical site and at the mirror-site in the contralateral groin assessed 6-8 weeks after unilateral, primary, open groin hernia repair following administration of naloxone/placebo.
Time frame: 1st session: 6-8 weeks; 2nd session: one week later
Pain Catastrophizing Scale
Patients fill out Pain Catastrophizing Scale before assessments on the first study day
Time frame: in the 1st session: 6-8 weeks after surgery
Hospital Anxiety and Depression Scale
Patients fill out Hospital Anxiety and Depression Scale before assessments on the first study day
Time frame: in the 1st session: 6-8 weeks after surgery
Clinical Opiate Withdrawal Scale
Clinical Opiate Withdrawal Scale is filled out before and during naloxone/placebo administration in each experimental session
Time frame: 1st session: 6-8 weeks after surgery; 2nd session: one week later
Ran from Nov 2015 to primary completion in Dec 2015, 1 month.
Of 124 non-industry phase 2 interventional studies under Pain, half reached primary completion within 33 months of starting (the median), counting those still running; a quarter within 13 and three quarters within 60. This study's 1 month is below that.
Counting every sponsor, half of 186 studies reached it within 21 months; a quarter within 7 and three quarters within 40.
How these figures are worked out, and which studies are left out of them.
This study is completed, as verified in Feb 2024. You cannot join it, but the record below documents what was studied.
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