Effect of High-dose Target-controlled Naloxone Infusion on Pain and Hyperalgesia During a Burn Injury

• Status: Completed
• Trial end date: 2017-01-01
• Target enrollment: 0
• Participant gender: Male

Summary

In several rodent studies, it has been demonstrated that very high doses of opioid antagonists (i.e., naloxone 3-10 mg/kg) administered after weeks after recovery from an inflammatory injury may lead to a reinstatement of hyperalgesia and pain behavior. This latent sensitization has recently been demonstrated also to take place in humans.

The present study examines if it is possible to foresee individuals who will demonstrate a larger degree of latent sensitization upon challenge with an injury, than others. Using an enriched design high sensitizers (e.g., the upper quartile of individuals developing large areas of secondary hyperalgesia following a mild burn injury) are compared with low sensitizers (lower quartile), regarding the propensity for developing latent sensitization

• Phase: Phase 2
• Accepts Healthy Volunteers?: Accepts Healthy Volunteers

Details

• Lead Sponsor: mads u werner
• Collaborator: University of Kentucky
• Treatments: Naloxone

Criteria

Inclusion Criteria:

• Healthy male

• Signed informed consent

• Urin-sample without traces of opioids (morphine, methadone, buprenorphine, codeine, tramadol, ketobemidone, oxycodone, hydromorphone, dextro-methorphan)

• ASA I

• Body mass index (BMI): 18 < BMI < 30 kg/sq.m

In addition Days 2-4:

• Secondary hyperalgesia areas 1 hr after a burn injury belonging to the upper quartile (Q3: high-sensitizers [n = 20]) or the lower quartile (Q1: low-sensitizers [n = 20]) The selection is made during a separate test day (Day 0 [n = 80]).

Exclusion Criteria:

• Participants, who do not speak or understand Danish

• Participants, who cannot cooperate with the investigation

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

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

• Use of psychotropic drugs

• Neurologic or psychiatric disease

• Signs of neuropathy in the examination region

• Previous severe trauma to the lower legs with sequelae

• Scarring or tattoos in the examination areas

• Chronic pain condition

• Regular use of analgesic drugs

• Use of prescription drugs one week before the trial

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

• Does not develop measurable secondary hyperalgesia areas after BI