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

NCT00689585 | Terminated Phase 2

• 1 other identifier: GEN#07-062
• Study Type: interventional
• Target: 4
• Locations: 1 country
• Sites: 1

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.

Conditions

Complex Regional Pain Syndromes

Keywords

Complex Regional Pain Syndrome; Reflex Sympathetic Dystrophy; RSD; Chronic Pain; Ethosuximide; Zarontin; Anticonvulsant

Outcome Measures

Primary Outcomes (1)

• 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

Secondary Outcomes (5)

• Pain Intensity Scores on the Visual Analogue Scale (VAS)

  up to 7 weeks

• Pain Intensity Scores on the Numerical Rating Scale (NRS)

  up to 5 weeks

• Neuropathic Pain Symptom Inventory (NPSI)

  up to 7 weeks

• Short Form 12v2 (SF-12v2)

  up to 7 weeks

• Short Form McGill Pain Questionnaire (SF-MPQ)

  up to 7 weeks

Study Arms (2)

1

PLACEBO COMPARATOR

Drug: Placebo

2

EXPERIMENTAL

Drug: Ethosuximide

Interventions

Placebo DRUG

250mg matching placebo capsules

1

Ethosuximide 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.

Also known as: Zarontin

2

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• 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.

You may not qualify if:

• 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.

Sponsors & Collaborators

• McGill University Health Centre/Research Institute of the McGill University Health Centre: lead
• McGill University: collaborator

Study Sites (1)

McGill University Health Centre

Montreal, Quebec, H3G 1A4, Canada

Location

MeSH Terms

Conditions

Complex Regional Pain Syndromes; Reflex Sympathetic Dystrophy; Chronic Pain

Interventions

Ethosuximide

Condition Hierarchy (Ancestors)

Autonomic Nervous System Diseases; Nervous System Diseases; Peripheral Nervous System Diseases; Neuromuscular Diseases; Pain; Neurologic Manifestations; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Intervention Hierarchy (Ancestors)

Succinimides; Imides; Organic Chemicals; Pyrrolidinones; Pyrrolidines; Heterocyclic Compounds, 1-Ring; Heterocyclic Compounds

Study Officials

• Mark A Ware, MD

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

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER

Study Record Dates

• First Submitted: May 29, 2008
• First Posted: June 3, 2008
• Study Start: September 1, 2008
• Primary Completion: July 1, 2010
• Study Completion: July 1, 2010
• Last Updated: May 13, 2011

Record last verified: 2011-05

Locations

CA (1)