Clinical trial NCT01935206: Effect of High Dose Naloxone on Secondary Hyperalgesia
Official title: Effect of a High-dose Naloxone Infusion on Secondary Hyperalgesia After a First-degree Burn
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE1
Conditions: Hyperalgesia
Pain
Naloxone
Opioid Antagonist
Keywords: secondary hyperalgesia
allodynia
mechanical pain threshold
naloxone
endogenous opioids
pain
Lead sponsor: Rigshospitalet, Denmark
Sponsor class: OTHER
First posted: 2013-09-05
Enrollment: 15
Sex: MALE
Minimum age (years): 20
Maximum age (years): 35
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: BASIC_SCIENCE

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.


Eligibility criteria: 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

Primary outcomes:
measure: Change in Secondary hyperalgesia area (cm2) surrounding a first-degree burn injury before and after infusion of naloxone/placebo
timeFrame: 1h, 2h, 3h, 168h, 168h15min, 168h30min post-burn
Secondary outcomes:
measure: Change in allodynic area (cm2) surrounding a first-degree burn injury before and after infusion of naloxone/placebo
timeFrame: 1h, 2h, 3h, 168h, 168h15min, 168h30min post-burn
Other outcomes:
measure: Change in Mechanical Pain Thresholds at primary hyperalgesia site before and after naloxone/placebo infusion
timeFrame: 0h, 168h, 168h30min
Locations:
city: Copenhagen
country: Denmark
facility: Dept Anaesthesiology HOC, 4231, Rigshospitalet
city: Copenhagen
country: Denmark
facility: Multidisciplinary Pain Center
Study officials:
affiliation: Dept Anaesthesiology, HOC, 4231, Rigshospitalet
name: Joergen B Dahl, M.D., DMSc
role: STUDY_DIRECTOR
affiliation: Multidisciplinary Pain Center, 7612, Rigshospitalet, Copenhagen
name: Mads U. Werner, M.D., Ph.D., DMSc
role: PRINCIPAL_INVESTIGATOR
References: