Pregabalin Versus Placebo as an Add on for Complex Regional Pain Syndrome (CPRS) of the Upper Limb Managed by Stellate Ganglion Block (The PREGA Study)

Study Overview
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Brief Summary
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The purpose of this study is to assess the efficacy of pregabalin in patients with complex regional pain syndrome Type I and to determine whether it provides clinically significant pain relief and whether it improves functioning of the upper limb.

Official Title
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Pregabalin vs. Placebo as an Add on for Complex Regional Pain Syndrome of the Upper Limb Managed by Stellate Ganglion Block

Conditions
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Complex Regional Pain Syndromes

Intervention / Treatment
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* Drug: Pregabalin
* Other: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients diagnosed with CRPS Type I as per the IASP (International Association for the Study of Pain) criteria which states presence of an initiating noxious event, or cause for immobilization Evidence at some point of swelling, color change, hot/cold/sweaty sensation and no other condition which can account for the pain and dysfunction of the upper limb Men or women between ages 18-65 year old Women should not be pregnant or breast feeding No change in treatment for 4 weeks prior to recruitment Pain scores of 4/10 on a verbal analogue scale Exclusion Criteria: Patients with a neurologic disorder unrelated to CRPS Patients who are already on pregabalin Patients with renal impairment whose creatinine clearance is less than 60 ml/min Patients with congestive heart failure who are also diabetic and taking thiazolidinedione medication like rivoglitazone Unstable psychiatric history Patients with another problem with equal or worse pain Unstable medical condition

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 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: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: 1<br>Pregabalin group is made up of 20 patients. Patients will receive 150mg/day in two divided does. The patients will be assessed weekly and the dose can be increased to 300mg/day, if the patient does not report any decrease in pain. The following week the dose may be increased to 600mg/day if once again the patient reports no decrease in pain. This is also the maximum permissible does that will be given to the patient. If patient reports any side effects then the dose can be decreased once. The time period of 2 to 5 weeks will be the dose adjustment period. After which the drug maintenance period extends from week 5 to 12. All doses will be given in two divided doses/day. | Drug: Pregabalin<br>* Dose of 150mg/day divided in two doses. Increased to 300mg/day then to 600mg/day, always divided in two doses for the day.<br>* Other names: Lyrica;|
| Placebo Comparator: 2<br>Ten patients will be be in the placebo group. | Other: Placebo<br>* Sugar pill<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pain relief assessed by an observer blinded to group allocation with daily pain scores and assessed weekly. |  | Three months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Functional disability assessed by an observer blinded to group allocation. Patient rated wrist and hand evaluation form. |  | Three months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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CPRS, stellate ganglion block, pregabalin, pain, Type I