Effect of High Dose Naloxone on Secondary Hyperalgesia

Sponsor

Rigshospitalet, Denmark (Other)

Overall Status

Completed

CT.gov ID

NCT01935206

Collaborator

(none)

Enrollment

Locations

Arms

Duration (Months)

7.5

Patients Per Site

1.5

Patients Per Site Per Month

Study Details

Study Description

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.

Condition or Disease	Intervention/Treatment	Phase
Hyperalgesia Pain Naloxone Opioid Antagonist	Drug: Naloxone (2 mg/kg) Drug: Placebo	Phase 1

Study Design

Study Type:

Interventional

Actual Enrollment :

15 participants

Allocation:

Randomized

Intervention Model:

Crossover Assignment

Masking:

Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)

Primary Purpose:

Basic Science

Official Title:

Effect of a High-dose Naloxone Infusion on Secondary Hyperalgesia After a First-degree Burn

Study Start Date :

Jun 1, 2013

Actual Primary Completion Date :

Nov 1, 2013

Actual Study Completion Date :

Nov 1, 2013

Arms and Interventions

Arm	Intervention/Treatment
Placebo Comparator: 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.	Drug: Placebo
Experimental: 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.	Drug: Naloxone (2 mg/kg)

Arm

Intervention/Treatment

Placebo Comparator: 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.

Drug: Placebo

Experimental: 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.

Drug: Naloxone (2 mg/kg)

Outcome Measures

Primary Outcome Measures

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

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.

Other Outcome Measures

Change in Mechanical Pain Thresholds at primary hyperalgesia site before and after naloxone/placebo infusion [0h, 168h, 168h30min]
Mechanical Pain Thresholds will be assessed with pinprick stimulators at baseline and after infusion of naloxone/placebo at the primary hyperalgesia site (following a first degree burn) and in the contralateral leg.

Eligibility Criteria

Criteria

Ages Eligible for Study:

20 Years to 35 Years

Sexes Eligible for Study:

Male

Accepts Healthy Volunteers:

Yes

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

Contacts and Locations

Locations

	Site	City	State	Country	Postal Code
1	Dept Anaesthesiology HOC, 4231, Rigshospitalet	Copenhagen		Denmark	2100
2	Multidisciplinary Pain Center	Copenhagen		Denmark	2100

Sponsors and Collaborators

Rigshospitalet, Denmark

Investigators

Study Director: Joergen B Dahl, M.D., DMSc, Dept Anaesthesiology, HOC, 4231, Rigshospitalet
Principal Investigator: Mads U. Werner, M.D., Ph.D., DMSc, Multidisciplinary Pain Center, 7612, Rigshospitalet, Copenhagen