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

NCT ID: NCT00689585

Last Updated: 2011-05-13

Basic Information

• Recruitment Status: TERMINATED
• Clinical Phase: PHASE2
• Total Enrollment: 4 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2008-09-30
• Study Completion Date: 2010-07-31

Brief 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.

Detailed 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.

Conditions

Complex Regional Pain Syndromes

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: QUADRUPLE

Study Groups

1

Group Type: PLACEBO_COMPARATOR

Placebo

Intervention Type: DRUG

250mg matching placebo capsules

2

Group Type: EXPERIMENTAL

Ethosuximide

Intervention Type: DRUG

500-1500mg/day over a 1-5 week dose titration period until maximal tolerated dose (MTD) attained, followed by 1 week MTD plateau period.

Interventions

Placebo

250mg matching placebo capsules

Intervention Type: DRUG

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.

Intervention Type: DRUG

Other Intervention Names

Zarontin

Eligibility Criteria

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.

• Minimum Eligible Age: 18 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

McGill University

OTHER

Sponsor Role: collaborator

McGill University Health Centre/Research Institute of the McGill University Health Centre

OTHER

Sponsor Role: lead

Responsible Party

McGill University Health Centre - Pain Centre

Principal Investigators

Mark A Ware, MD

Role: PRINCIPAL_INVESTIGATOR

McGill University Health Centre/Research Institute of the McGill University Health Centre

Locations

McGill University Health Centre

Montreal, Quebec, Canada

Countries

Canada

Other Identifiers

GEN#07-062

Identifier Type: -

Identifier Source: org_study_id