Efficacy of Pregabalin in Patients With Radicular Pain

Study Overview
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Brief Summary
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The purpose of this study is to evaluate whether pregabalin is effective in reducing the pain in patients who present with radicular pain due to a herniated disc, spinal stenosis or failed back surgery syndrome.

Detailed Description
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Although the efficacy of pregabalin has been demonstrated in several pain states and it is approved by the FDA for use in post herpetic neuralgia, diabetic neuropathy and fibromyalgia there are few studies of its efficacy in patients with radicular pain from herniated disc, spinal stenosis or failed back surgery syndrome. This study was conducted to evaluate the efficacy of pregabalin in these pain states.

Official Title
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Efficacy of Pregabalin in Patients With Radicular Pain

Conditions
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Neuropathy; Radicular, Lumbar, Lumbosacral, Failed Back Surgery Syndrome, Spinal Stenosis, Herniated Disc

Intervention / Treatment
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* Drug: Pregabalin
* Drug: Sugar Pill


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients with pain in dermatomal distribution, in either cervical or lumbar region. History of pain for more than 3 months. History of herniated disc, spinal stenosis or failed back surgery. A series of epidural steroid injections within the past 6 months. Presence of motor or sensory neurological signs (hypoesthesia, hyperesthesia, allodynia, dysesthesia) in the affected dermatomes. Patients must be cognitively capable of completing the pain questionnaires. Exclusion Criteria: Patients below 18 or over 65 years of age. Patients with mostly axial spinal pain. Presence of significant motor deficits, and /or bowel and/or bladder dysfunction. Workmen's compensation or disability issues. Patients with chronic depression and on depression medications. Addiction and/or substance abuse issues. Patients using gabapentin or failure to respond to previous gabapentin use. Patients with known peripheral neuropathy (e.g. DPN, PHN etc.). Known hypersensitivity to pregabalin use (hives, blisters, rash, dypnea and wheezing). History of angioedema with pregabalin use. Patients with known renal insufficiency, diabetes, congestive heart failure, cardiac conduction abnormalities, and/or thrombocytopenia. Patients using ACE-inhibitors and thiazolidinedione antidiabetic agents (Avandia®, Actos®). Pregnant patients.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 64 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: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Pregabalin<br>A 75mg pregabalin capsule will be prescribed twice daily for the first week of the study (150mg/day). For the subsequent 2 weeks, the dose will be increased to 2 pregabalin capsules twice a day (300mg/day). The total duration of the treatment will be 3 weeks. | Drug: Pregabalin<br>* One pregabalin 75mg capsule will be prescribed twice daily for the first week of the study (150mg/day). For the subsequent 2 weeks, the dose will be increased to 2 pregabalin capsules twice a day (300mg/day). The total duration of the treatment will be 3 weeks.<br>* Other names: Lyrica®, Pfizer NY, NY 10017;|
| Placebo Comparator: Surgar Pill<br>One Sugar pill capsule will be prescribed twice daily for the first week of the study. For the subsequent 2 weeks, 2 Sugar pill capsules twice a day. The total duration of the treatment will be 3 weeks. | Drug: Sugar Pill<br>* One sugar pill will be prescribed twice daily for the first week of the study. For the subsequent 2 weeks, 2 placebo(sugar pills) capsules twice a day. The total duration of the treatment will be 3 weeks.<br>* Other names: Placebo;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pain Scores (NRS) at 3-weeks | Standard numeric rating pain scale ranging from 0 (no pain) to 10 (worst pain imaginable) after 3 weeks of treatment. . | 3 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Patient's Global Impression of Change at 3 Weeks | Global impression of change in patient status reported at 3 weeks. The global impression of change consists of a Likert scale as below: Very Much Improved Much Improved Minimally Improved No Change Minimally Worse Much Worse Very Much Worse | 3 weeks | 
| Oswestry Disability Questionnaires | Oswestry disability index (ODI) is a tool to measure a subject's functional disability. The Oswestry disability index consists of 10 questions with a Likert 0-5 scale. Each individual score is converted into a percent which represents the percent disability. There are five tiers, 0-20% (minimal disability), 21%-40% (moderate disability), 41%-60% (severe disability), 61%-80% (crippled), 81%-100% (i.e. bed bound). We report the Oswestry disability scores at 3 weeks. | 3 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Pregabalin, Radicular pain, Failed back surgery, Of greater than 3 months duration