Mechanism-based Choice of Therapy for Neuropathic Pain

Study Overview
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Brief Summary
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Mechanism-based choice of therapy for neuropathic pain: Can treatments success in neuropathic post-operative pain be coupled to psychophysical pain modulation profile?

Detailed Description
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Neuropathic or idiopathic pain patients will be assessed with the variety of pain tests including the conditioned pain modulation (CPM) and temporal summation (TS). Then, they will be offered on the double-blind design a several weeks treatment with either pregabalin or duloxetine. Patients will be followed-up weekly by phone for their pain relief and will be re-assessed in the lab toward the end of the treatment. The investigators suggest that patients with less-efficient CPM (deficient pain inhibition) will earn more pain relief from the treatment with duloxetine, while the patients with the enhanced pain summation will response better to pregabalin.

Official Title
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Mechanism-based Choice of Therapy for Neuropathic Pain: Can Treatments Success in Neuropathic Post-operative Pain be Coupled to Psychophysical Pain Modulation Profile?

Conditions
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Pain

Intervention / Treatment
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* Drug: Pregabalin
* Drug: Duloxetine


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: patients planned for thoracotomy Exclusion Criteria: age below 18 and above 75 years patients with psychiatric or cognitive dysfunction precluding use of psychophysics those who cannot communicate in Hebrew patients with existing thoracic or other current chronic pain

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Duloxetine<br> | Drug: Pregabalin<br>* Initial dose of 75x2mg/d for one week, and then fixed dose of 150x2mg/d for the following 5 weeks<br>* Other names: Calcium-channel blocker;|
| Active Comparator: Pregabalin<br> | Drug: Duloxetine<br>* Initial dose of 30 mg/d will be given for one week, in order to minimize possible side effects and drop outs, and then a fixed dose of 60 mg/d will be given for additional 5 weeks<br>* Other names: SSNRI;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| clinical pain | The pain relief will be achieved by treatment with duloxetine or pregabalin. We propose that the patients with deficient pain inhibition (As assessed by conditioned pain modulation lab test) will have better drug efficacy of cymbalta which restores the deficient level of serotonin and noradrenalin. In turn, pregabalin will be more effective in patients with enhance central sensitization of pain as measured by temporal summation assessment. In line, CPM and TS will be modulated by the treatment, in parallel with the analgesic effect. | One year |