Effect of High-dose Naloxone Infusion on Pain and Hyperalgesia in Patients Following Groin-Hernia Repair.

Pain Clinical Trial

Official title:

Effect of High-dose Naloxone Infusion on Pain and Hyperalgesia in Patients Following Groin-Hernia Repair. A Randomized, Placebo-controlled, Double-blind Crossover Study

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT01992146
• Other study ID #: MP_SM01_2013
• Status: Completed
• Phase: Phase 2
• Start date: November 11, 2015
• Est. completion date: May 11, 2018

Study information

• Verified date: February 2024
• Source: Rigshospitalet, Denmark
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 9
• Est. completion date: May 11, 2018
• Est. primary completion date: December 14, 2015
• Accepts healthy volunteers: No
• Gender: Male
• Age group: 18 Years to 65 Years

Eligibility

Inclusion Criteria:

• Age = 18 years and = 65 years

• Signed informed consent

• Patients submitted to unilateral, primary inguinal, open herniotomy 6-8 weeks prior to study start.

• Open operating procedure a.m. Lichtenstein.

• Urin sample without traces of opioids (morphine, methadon, buprenorphine, codeine, tramadol, ketobemidone, oxycodone, hydromorphine, dextromethorphan)

• ASA I-II

• Body mass index (BMI): 18 < BMI < 30

Exclusion Criteria:

• Volunteers , who do not speak or understand Danish

• Patients, who cannot cooperate with the investigation

• Patients who have had previous surgery in the groin region

• Patients with pain at rest > 3 (NRS)

• Activity-related pain in the surgical field > 5

• Allergic reaction against morphine or other opioids (including naloxone),

• Abuse of alcohol or drugs - according to investigator's evaluation

• Use of psychotropic drugs (exception of SSRI)

• Neurologic or psychiatric disease

• Chronic pain condition

• Regular use of analgesic drugs

• Skin lesions and tattoos in the assessment areas

• Nerve lesions in the assessment sites (for instance, after trauma, disc herniation, etc.)

• Use of prescription drugs 1 week before the trial

• Use of over-the-counter drugs 48 hours before the trial

Related Conditions & MeSH terms

• Central Nervous System Sensitization
• Hernia
• Hernia, Inguinal
• Hyperalgesia
• Pain

Intervention

Drug:
• Target-controlled naloxone-infusion

• Placebo

Locations

Country	Name	City	State
Denmark	Multidisciplinary Pain Center, 7612, HOC, Rigshospitalet	Copenhagen

Sponsors (3)

Lead Sponsor	Collaborator
Rigshospitalet, Denmark	National Institute on Drug Abuse (NIDA), University of Kentucky

Country where clinical trial is conducted

Denmark, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Other	Pain Catastrophizing Scale	Patients fill out Pain Catastrophizing Scale before assessments on the first study day	in the 1st session: 6-8 weeks after surgery
Other	Hospital Anxiety and Depression Scale	Patients fill out Hospital Anxiety and Depression Scale before assessments on the first study day	in the 1st session: 6-8 weeks after surgery
Other	Clinical Opiate Withdrawal Scale	Clinical Opiate Withdrawal Scale is filled out before and during naloxone/placebo administration in each experimental session	1st session: 6-8 weeks after surgery; 2nd session: one week later
Primary	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.	1st session: 6-8 weeks after surgery; 2nd session: one week later
Secondary	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.	1st session: 6-8 weeks after surgery; 2nd session: one week later
Secondary	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.	1st session: 6-8 weeks; 2nd session: one week later