Effect of High Dose Naloxone on Secondary Hyperalgesia

Phase 1

Completed

• Conditions: Hyperalgesia; Naloxone; Opioid Antagonist; Pain
• Interventions: Drug: Placebo; Drug: Naloxone (2 mg/kg)

• Registration Number: NCT01935206
• Lead Sponsor: Rigshospitalet, Denmark

Brief 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 naloxone (2 mg/kg) can reinstate secondary hyperalgesia 168 hours after a first-degree burn-injury. Investigators aim therefore to show that latent sensitization is present in humans and is modulated by endogenous opioids.

Detailed Description

Not available

Study Timeline

• Study Start: 2013-06
• Study First Submitted: 2013-08-19
• Study First Submitted QC: 2013-08-30
• Study First Posted: 2013-09-05
• Primary Completion: 2013-11
• Study Completion: 2013-11
• Status Verified: 2014-02
• Last Update Submitted: 2014-02-24
• Last Update Posted: 2014-02-25

Recruitment & Eligibility

• Status: COMPLETED
• Sex: Male
• Target Recruitment: 15

Inclusion Criteria

• healthy man
• written informed consent
• ASA 1-2
• BMI 18 < BMI < 30
• normal ultrasound examination of the heart
• normal ECG
• urin sample without traces of opioids

Exclusion Criteria

• volunteers, who do not understand the Danish language
• participation in another experimental trial in the previous 60 days
• nerve damage or skin lesions in the assessment areas
• neurological or psychiatric condition
• use of psycho-active drugs
• abuse of alcohol or drugs
• chronic pain
• regular use of pain-killers (> 1 a week)
• allergy against morphine or other opioids (including naloxone)
• use of prescription drugs 1 week prior to the trial
• use of over-the-counter medication 48 hours prior to the trial
• urin sample with traces of opioids
• volunteer is not suitable for the trial according to the investigator's consideration

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Placebo	Placebo	The effect of naloxone (2 mg/kg) on secondary hyperalgesia 168 hours after a first-degree burn-injury is compared to the placebo effect.
Naloxone (2 mg/kg)	Naloxone (2 mg/kg)	The effect of naloxone (2 mg/kg) on secondary hyperalgesia 168 hours after a first-degree burn-injury is compared to the placebo effect.

Primary Outcome Measures

Name	Time	Method
Change in Secondary hyperalgesia area (cm2) surrounding a first-degree burn injury before and after infusion of naloxone/placebo	1h, 2h, 3h, 168h, 168h15min, 168h30min post-burn	Areas of secondary hyperalgesia surrounding a first degree burn-injury will be assessed before and after infusion of naloxone/placebo.

Secondary Outcome Measures

Name	Time	Method
Change in allodynic area (cm2) surrounding a first-degree burn injury before and after infusion of naloxone/placebo	1h, 2h, 3h, 168h, 168h15min, 168h30min post-burn	Areas of allodynia surrounding a first degree burn-injury will be assessed before and after infusion of naloxone/placebo.

Trial Locations

Locations (2)

Dept Anaesthesiology HOC, 4231, Rigshospitalet; 🇩🇰 Copenhagen, Denmark

Multidisciplinary Pain Center; 🇩🇰 Copenhagen, Denmark