Oxcarbazepine for the Treatment of Chronic Peripheral Neuropathic Pain

Study Overview
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Brief Summary
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The purpose of this trial is to determine if the effect of oxcarbazepine on chronic peripheral nerve pain depends on the supposed mechanism of the pain, ie. if oxcarbazepine mainly relieve pain in patients with irritable nerves.

Official Title
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Oxcarbazepine for the Treatment of Chronic Peripheral Neuropathic Pain: Predictors of Response - a Randomised, Double-blind, Placebo-controlled Clinical Trial

Conditions
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Polyneuropathy, Peripheral Nerve Injury, Postherpetic Neuralgia

Intervention / Treatment
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* Drug: Oxcarbazepine


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: age > 18 years old definite or probable neuropathic pain diagnosis of polyneuropathy, postherpetic neuralgia or peripheral nerve inju pain duration > 3 months pain rating at baseline >= 4 point NRS Informed consent Exclusion Criteria: other non-neuropathic pain condition allergy to oxcarbazepine renal or hepatic impairment epilepsy depression and other serious psychiatric disorders serious medical condition previous treatment for neuropathic that cannot be stopped pregnancy patients expected not to be able to comply with study protocol treatment with anticonvulsants, antidepressant or opioids

Ages Eligible for Study
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Minimum Age: 18 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: Crossover Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: oxcarbazepine<br>Oxcarbazepine is gradually increased during 21 days from 300 mg x 1 daily to 2400 mg, and kept on that dose ( 2400 mg) for three weeks. | Drug: Oxcarbazepine<br>* Oxcarbazepine capsules 300 mg is gradually increased from 300 mg/day to 2400 mg/day Placebo capsules increase from 1/day to 8/day<br>* Other names: Trileptal;|
| Placebo Comparator: placebo<br> | Drug: Oxcarbazepine<br>* Oxcarbazepine capsules 300 mg is gradually increased from 300 mg/day to 2400 mg/day Placebo capsules increase from 1/day to 8/day<br>* Other names: Trileptal;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Total pain rated on numeric rating scale | Pain is rated daily on 0-10 point numeric rating scales. From the daily ratings from week 6 of each treatment period a median value is determined and used for data analysis. The analysis will compare scores between treatments (oxcabazepine vs placebo) and treatment effects (placebo-oxcarbazepine) between groups irritable nociceptor vs non-irritable nociceptors and some other subgroups. | Measurements from week 6 of treatment period | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Response defined as at least 50% reduction in pain score | Response defined as 50% reduction in pain score (median value week 6 of treatment period compared to median value during baseline period). Repsonse rates for each treatment and each phenotype will be calculated | Week 6 of each treatment period vs. baseline | 
| Neuropathic Pain Symptom Inventory | Different pain dimensions as rated by Neuropathic Pain Symptom Inventory | Week 6 of each treatment period | 
| Patient Global Impression of Change |  | Week 6 of each treatment period | 
| Rating of evoked pain | Rating on numeric rating scales of pain induced by stimulation with cold rollers, stiff von Frey hain and dynamic touch with rubber sponge | Week 6 of each treatment period | 
| Sleep disturbance | Numeric rating scale ratings of pain induced sleep disturbance, median value of ratings from week 6 of each treatment period | Week 6 of each treatment period | 
| Quality of life | Rating of quality of life with numeric rating scale | Week 6 of each treatment period | 
| Use of escape medication | Number of paracetamol 500 mg used during the last week of each treamtent period | Week 6 of each treatment period | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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neuropathic pain, oxcarbazepine, pain mechanism