Effect of Opioids in Neuropathic Pain in Postherpetic Patients
Status:
Unknown status
Trial end date:
2011-03-01
Target enrollment:
Participant gender:
Summary
Postherpetic neuralgia (PHN) is often associated with pain and sensory changes and is the
leading type of neuropathic pain in modern clinical pain research. It is characterized by a
variety of sensory patterns, which may be categorized into "irritable nociceptor" and
"impairment of nociceptor". At date, several lines of evidence lead to the assumption, that
mechanical hyperalgesia in PHN is based - at least in part - on central nervous processes of
sensitization.
In animal studies the investigators have discovered a previously unrecognized effect of
opioids, the reversal of long-term potentiation (LTP) at C-fibre synapses, i.e. an
opioid-induced depotentiation. In principle, synaptic depotentiation may be permanent or
transient. In our study the clinically used ultra-short acting MOR agonist remifentanil
normalized synaptic strength after wash-out of the drug. At present it is not known whether
opioid-induced depotentiation can be used to the benefit of pain patients.
The aim is to study the hypothesis, that pain in a group of PHN patients with predominant
mechanical hyperalgesia is reversed by intravenous remifentanil at a plasma target
concentration of 18ng/ml (corresponding to about 0.75 µg/kg/min) for 60 minutes compared with
PHN patients of other sensory types.
Phase:
Phase 3
Details
Lead Sponsor:
Medical University of Vienna
Collaborators:
Vienna General Hospital WWTF, Wiener Wissenschafts-, Forschungs- und Technologiefonds