Safety and Efficacy Study of Ethosuximide for the Treatment of Complex Regional Pain Syndrome (CRPS)

Complex Regional Pain Syndromes Clinical Trial

Official title:

A Single Centre. Parallel-Group, Double-Blinded, Randomized, Placebo-Controlled Pilot Clinical Trial on Ethosuximide for the Treatment of Complex Regional Pain Syndrome (CRPS)

Clinical Trial Details — Status: Terminated

Administrative data

• NCT number: NCT00689585
• Other study ID #: GEN#07-062
• Status: Terminated
• Phase: Phase 2
• First received: May 29, 2008
• Last updated: May 11, 2011
• Start date: September 2008
• Est. completion date: July 2010

Study information

• Verified date: May 2011
• Source: McGill University Health Center
• Contact: n/a
• Is FDA regulated: No
• Health authority: Canada: Health Canada
• Study type: Interventional

Clinical Trial Summary

Pain remains the most debilitating symptom for adult patients suffering from complex regional pain syndrome (CRPS). Most CRPS patients gain little to no relief from current painkillers. The purpose of this study is to evaluate the efficacy and safety of ethosuximide in search of much-needed adjunctive therapy to relieve the pain and suffering associated with CRPS.

Description:

This is a single centre, parallel-group, double-blind, randomized, placebo-controlled pilot clinical trial for adults suffering from complex regional pain syndrome (CRPS).

Twelve (12) subjects diagnosed with CRPS will be enrolled and randomized to receive orally, either ethosuximide or placebo. If the maximum trial medication dosage (1500mg) is reached, the subject will be in the study for a maximum of 10 weeks from screening (Clinic Visit 1) to the end of the drug cessation period. The minimum period a subject could complete the study would be 4 weeks presuming they were not previously on any disallowed drugs and only found the 500mg dose tolerable.

Recruitment information / eligibility

• Status: Terminated
• Enrollment: 4
• Est. completion date: July 2010
• Est. primary completion date: July 2010
• Accepts healthy volunteers: No
• Gender: Both
• Age group: 18 Years and older

Eligibility

Inclusion Criteria:

• Male or female, age =18 years old;

• Diagnosis of Complex Regional Pain Syndrome (CRPS) using International Association for the Study of Pain criteria >6 months;

• Normal liver function (AST level <3x normal level);

• Normal kidney function (serum creatinine <133µmol/L);

• Full blood count, haematocrit >38%;

• Willing and able to give informed consent and of completing study questionnaires;

• Stable (no change in past two months) but suboptimal pain pharmacotherapy (i.e. additional pain control felt by patient and physician to be necessary);

• Able to attend research centre according to the visit schedule;

• Women of child-bearing potential must be using a reliable form of contraception i.e. oral contraceptives, a barrier method (condom or diaphragm), intra-uterine device or abstinence.

Exclusion Criteria:

• Optimal response to opioids, antidepressants, anticonvulsants or anti- inflammatory medications;

• Any history or indication of kidney or liver disease;

• Any history of alcohol abuse;

• Presence of diabetes;

• Subjects taking other anti-epileptic drugs, including gabapentin, pregabalin, topiramate, phenytoin, carbamazepine, and oxcarbazepine;

• Pregnancy (a serum bHCG pregnancy test will be performed as part of the initial blood panel);

• Known or suspected allergy to succinimides, ethosuximide, methsuximide (Celontin®), phensuximide;

• Any history of mental illness or disorder, which in the investigators opinion, interferes with the subjects ability to accurately report treatment response;

• Participation in other clinical trial in the 30 days prior to enrolment.

Study Design

Allocation: Randomized, Endpoint Classification: Safety/Efficacy Study, Intervention Model: Parallel Assignment, Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor), Primary Purpose: Treatment

Related Conditions & MeSH terms

• Complex Regional Pain Syndromes
• Reflex Sympathetic Dystrophy
• Somatoform Disorders
• Syndrome

Intervention

Drug:
• Placebo
250mg matching placebo capsules
• Ethosuximide
500-1500mg/day over a 1-5 week dose titration period until maximal tolerated dose (MTD) attained, followed by 1 week MTD plateau period.

Locations

Country	Name	City	State
Canada	McGill University Health Centre	Montreal	Quebec

Sponsors (2)

Lead Sponsor	Collaborator
McGill University Health Center	McGill University

Country where clinical trial is conducted

Canada, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Maximum tolerated dose (500mg-1500mg per day) and Safety profile	Primary outcomes will consist of the dose attained during the study and the safety (adverse event) profile. Maximum timeframe on study drug is 6 weeks. Adverse events will be collected up to one month after the trial period ends.	up to 10 weeks	No
Secondary	Pain Intensity Scores on the Visual Analogue Scale (VAS)	Pain Intensity captured on Day 1 (First study visit post-disallowed drug cessation period) and 7 days after maximal-tolerated dose attained (Final Study Visit)	up to 7 weeks	No
Secondary	Pain Intensity Scores on the Numerical Rating Scale (NRS)	Pain Intensity using the Numerical Rating Scale will be captured by telephone every week during dose titration period (Days 3 and 6).	up to 5 weeks	No
Secondary	Neuropathic Pain Symptom Inventory (NPSI)	Day 1 (First study visit post-disallowed drug cessation period) and 7 days after maximal-tolerated dose attained (Final Study Visit)	up to 7 weeks	No
Secondary	Short Form 12v2 (SF-12v2)	Quality of Life measured on Day 1 (First study visit post-disallowed drug cessation period) and 7 days after maximal-tolerated dose attained (Final Study Visit)	up to 7 weeks	No
Secondary	Short Form McGill Pain Questionnaire (SF-MPQ)	Day 1 (First study visit post-disallowed drug cessation period) and 7 days after maximal-tolerated dose attained (Final Study Visit)	up to 7 weeks	No