Efficacy of Etoricoxib on Peripheral Hyperalgesia

Study Overview
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Brief Summary
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The purpose of the study is to determine the efficacy of etoricoxib on pain patients. The investigators assume that patients with neuropathic pain will have greater pain relief then patients on placebo.

Detailed Description
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Animal experiments analysing anti-hyperalgesic effects of Coxibs show inconsistent results due to different used dosages and varying different pain models. Theoretical the use of NSAIDs is rational, particularly of Coxibs as a part of the neuropathic pain management. But in the newest topical review, there is no valid information available about the effectiveness of these drugs in human neuropathic pain models or in patients with different underlying mechanism, e.g. with or without hyperalgesia.

Official Title
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Efficacy of Etoricoxib in Patients With Neuropathic Pain With and Without Peripheral Hyperalgesia - A Prove of Concept Trial

Conditions
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Causalgia, Polyneuropathy, Postherpetic Neuralgia, Peripheral Nerve Injury, Radiculopathy

Intervention / Treatment
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* Drug: Etoricoxib
* Drug: placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients over 18 years with Persistent moderate or severe pain (> 4 on NRS (1..10)) at rest (average of three daily assessments using a diary for at least two days) . Neuropathic pain associated with a clinical and neurologically proven peripheral nerve injury, radiculopathy, postherpetic neuralgia or polyneuropathy or CRPS One of the two following QST phenotypes at the baseline assessment: signs of peripheral hyperalgesia (that means, pathological decreased heat pain threshold and/or pathological decreased muscle pain threshold) without signs of peripheral hyperalgesia (no pathological decreased heat - and/or muscle pain threshold) Patients of both gender Signed consent form Patients with the ability to understand and follow the instructions of the doctor Exclusion Criteria: Excluded will be patients Parkinson's disease or a history of cerebral vascular insult or nerve injury. Excluded will be also all patients with contradictions for the use of Etoricoxib: Hypersensitivity to the active substance or to any of the excipients. Active peptic ulceration or active gastrointestinal (GI) bleeding. Patients who have experienced bronchospasm, acute rhinitis, nasal polyps, angioneurotic oedema, urticaria, or allergic-type reactions after taking acetyl-salicylic acid or NSAIDs including COX-2 (cyclooxygenase-2) inhibitors. Pregnancy and lactation Severe hepatic dysfunction (serum albumin <25 g/l or Child-Pugh score ≥10). Estimated renal creatinine clearance <30 ml/min. Inflammatory bowel disease. Congestive heart failure (NYHA II-IV). Patients with hypertension whose blood pressure is persistently elevated above 140/90mmHg and has not been adequately controlled Established ischemic heart disease, peripheral arterial disease, and/or cerebrovascular disease. Intake of one of the following drugs (current or in the last 3 days) selective-serotonin-reuptake-inhibitor cetoconazole rifampicin phenytoin carbamazepine dexamethasone or other systemic corticoids traditional nonsteroidal antiphlogistics cyclooxygenase-inhibitors immunosuppressives TNF-α-inhibitors

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: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: etoricoxib, peripheral hyperalgesia<br>14 patient with neuropathic pain and peripheral hyperalgesia get etoricoxib 90mg for 8 days | Drug: Etoricoxib<br>* the patients get etoricoxib 90mg for 8 days. They get one pill with 90mg per day<br>* Other names: Arcoxia;|
| Active Comparator: etoricoxib, no peripheral hyperalgesia<br>14 patients with neuropathic pain without peripheral hyperalgesia get etoricoxib 90mg for 8 days | Drug: Etoricoxib<br>* the patients get etoricoxib 90mg for 8 days. They get one pill with 90mg per day<br>* Other names: Arcoxia;|
| Placebo Comparator: placebo, peripheral hyperalgesia<br>14 patients with neuropathic pain with peripheral hyperalgesia get placebo for 8 days | Drug: placebo<br>* patients get one pill of placebo (sugar-pill) per day for 8 days.<br>|
| Placebo Comparator: placebo, no peripheral hyperalgesia<br>14 patients with neuropathic pain without peripheral hyperalgesia get placebo for 8 days | Drug: placebo<br>* patients get one pill of placebo (sugar-pill) per day for 8 days.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Superior improvement of peripheral hyperalgesia at day six after initiation of Cox-2-inhibiting-medication in comparison to placebo |  | 12 month | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Reduction of the average on-going pain | reduction of the average on-going pain decrease of the neuropathic symptoms intensity (NPSI score) decrease of the patients global impression of change (PGIC) decrease of the frequency and cumulative 7 day dosage of rescue medication | 12 month | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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CRPS, Morbus Sudeck, Causalgia, Etoricoxib, Polyneuropathy, post herpetic neuralgia, peripheral nerve injury, radiculopathy, Nervenverletzung, postherpetische Neuralgie, COX-2-Inhibitor