The Effect of Remifentanil on Established Capsaicin-Induced Hyperalgesia in Human Volunteers
Overview
- Phase
- Phase 4
- Intervention
- Remifentanil
- Conditions
- Hyperalgesia
- Sponsor
- Medical University of Vienna
- Enrollment
- 24
- Locations
- 1
- Primary Endpoint
- Area of pin prick hyperalgesia
- Last Updated
- 16 years ago
Overview
Brief Summary
Treatment of chronic pain is a major clinical challenge since chronic pain is frequent and leads to deterioration of quality of life. An injury or wound can lead to long term changes in the nervous system that make the skin more sensitive at and near the injury; this is termed hyperalgesia and occurs through long term depotentiation (LTP), i.e., a change in the synaptic interaction between neurons.
Opioids are the gold standard for the symptomatic therapy of moderate to severe pain. Now, in animal studies the investigators have discovered previously unrecognized effects of opioids.
Intradermal injection of capsaicin (injection of pepper extract into the skin) is an established pain model in humans. The investigators want to test the influence of remifentanil, an ultra-short acting opioid, on hyperalgesia observed after intradermal capsaicin in human volunteers in a double blind cross-over prospective active placebo controlled clinical trial.
Investigators
Eligibility Criteria
Inclusion Criteria
- •Body mass index between 15th and 85th percentile
- •Normal findings in the medical history and physical examination
- •Drug free for 1 week prior to the study day
Exclusion Criteria
- •Regular use of medication especially analgesics
- •Abuse of alcoholic beverages, drug abuse
- •History of asthma
- •Participation in a clinical trial in the 2 weeks preceding the study
- •Symptoms of a clinically relevant illness in the 2 weeks before the first study day
- •Resting systolic blood pressure \> 135 mmHg or diastolic blood pressure \> 85 mmHg
- •Acute skin diseases like sunburn on the relevant areas or skin lesions
- •Pregnancy or breast feeding
Arms & Interventions
Remifentanil
Intervention: Remifentanil
Midazolam
Active Placebo
Intervention: Midazolam
Outcomes
Primary Outcomes
Area of pin prick hyperalgesia
Time Frame: 0-6 hours
Secondary Outcomes
- Stimulus-response (SR)function to a set of modified rigid von Frey filaments (8-512 mN)(0-6 hours)
- Pain immediately after injection(0-15 minutes)
- Heat pain threshold within the area of mechanical hyperalgesia(0-6 hours)
- Mechanical pain threshold within the area of pin prick hyperalgesia, area of dynamic allodynia to brush(0-6 hours)
- Adverse effects(10 and 30 min after infusion of study medication)