Neurotropin to Treat Chronic Neuropathic Pain

Phase 2

Terminated

Conditions: Complex Regional Pain Syndrome Type I
Complex Regional Pain Syndrome Type II

Interventions: Drug: Placebo
Drug: Neurotropin

Registration Number: NCT00006289

Lead Sponsor: National Institute of Nursing Research (NINR)

Brief Summary: This study will examine the effectiveness of the drug neurotropin in treating chronic pain after injury to a limb or a large nerve.

Two groups of patients will participate in this study: patients with complex regional pain syndrome type 1, or CRPS-I (also called reflex sympathetic dystrophy) and patients with complex regional pain syndrome type 2, or CRPS-II. CRPS-I is pain that develops after relatively minor injury to an arm or leg, but lasts much longer and is much more severe than would normally be expected. CRPS-II is pain resulting from injury to a large nerve. Candidates will have a history and physical examination, blood tests, and electrocardiogram. Participants will undergo the following tests and procedures:

Patients with CRPS I and II will receive an individualized regimen of physical therapy and standard treatment to control their pain. In addition, they will receive neurotropin or placebo tablets for 5 weeks, then no trial medicine for at least 1 week, and then the other trial drug for the next 5 weeks. That is, patients who took placebo the first 5 weeks will take neurotropin the second 5 weeks and vice versa. Neither the patients nor the doctors will know who received which drug during the two intervals until the study is over. Patients will complete questionnaires about their pain, quality of life, and ability to perform daily living activities. They will have various tests to measure pain (such as sensitivity to heat and cold, to an electric current, to a mild pin prick, etc.); to provide information about changes in their condition (such as tests of range of motion of joints and limb size); to measure blood circulation and sweating in the arm or leg (such as measurements of blood flow to the limb, skin temperature, and sweat production), and other procedures.

Detailed Description: Patients with Reflex Sympathetic Dystrophy (RSD), re-named Complex Regional Pain Syndrome, type I (CRPS-I), have chronic, post-traumatic pain that spreads beyond the distribution of any single peripheral nerve without evidence of major peripheral nerve damage. A similar disorder, Causalgia, re-named CRPS-II, presents with clear evidence of nerve injury. No successful drug treatment exists for these disorders. Neurotropin is a non-protein extract of cutaneous tissue from rabbits inoculated with vaccinia virus. Neurotropin has been used extensively in Japan to treat RSD and other painful conditions; however, the drug has not undergone clinical therapeutic testing in the United States. This protocol is to carry out double-blind, placebo-controlled, crossover studies about clinical efficacy of Neurotropin for acute pain in dental outpatients and for chronic pain in outpatients with CRPS-I or II.

Recruitment & Eligibility

Status: TERMINATED

Sex: All

Target Recruitment: 21

Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Study & Design

Study Type: INTERVENTIONAL

Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Placebo first, then Neurotropin (G-1)	Placebo	Double blind cross-over study: receive placebo for 5 weeks and then Neurotropin for 5 weeks (after at least 1 week washout period). Assignment to each group was in random order, selected by the pharmacy with all others blind.
Neurotropin first, then Placebo (G-2)	Placebo	Double blind cross-over study: receive Neurotropin for 5 weeks and then placebo for 5 weeks (after at least 1 week washout period). Assignment to each group was in random order, selected by the pharmacy with all others blind.
Neurotropin first, then Placebo (G-2)	Neurotropin	Double blind cross-over study: receive Neurotropin for 5 weeks and then placebo for 5 weeks (after at least 1 week washout period). Assignment to each group was in random order, selected by the pharmacy with all others blind.
Placebo first, then Neurotropin (G-1)	Neurotropin	Double blind cross-over study: receive placebo for 5 weeks and then Neurotropin for 5 weeks (after at least 1 week washout period). Assignment to each group was in random order, selected by the pharmacy with all others blind.

Primary Outcome Measures

Name	Time	Method
Visual Analogue Scale (VAS) of Pain Scores After Administration of Test Drugs (Placebo or Neurotropin )	VAS of each patient is measured after each 5-week treatment interval with placebo or Neurotropin.	Assessments of pain severity by the patient using a visual analogue scale ranging from 0 to 100 (mm), with 0 = no pain and 100 = maximal pain level. When it is difficult to recruit the patients, the interim analysis using these data is performed after completion of the study of first 16 patients (target number is 30). The data from 16 patients was analyzed while investigators were blinded to the treatment code (Drug A and B) provided by the NIH pharmacy. Only after the analysis was completed was the code unblinded. Placebo or Neurotropin" in place of "drug A or drug B.
Numeric Rating Scale (NRS) of Pain Scores After Administration of Test Drugs (Neurotropin or Placebo)	NRS of each patient is measured after each five-week treatment interval with placebo or Neurotropin.	Assessments of pain severity by the patient using a numeric rating scale ranging from 0 to 10 as a verbal response where 0 = no pain and 10 =maximal pain. When it is difficult to recruit the patients, the interim analysis using these data is performed after completion of the study of first 16 patients (target number is 30). The data from 16 patients was analyzed while the investigators are blinded to the treatment code (Drug A or B) provided by the NIH pharmacy. Only after the analysis was completed was the code unblinded. Placebo or Neurotropin" in place of "drug A or drug B.
McGill Pain Questionnaire (MPQ) of Scores After Administration of Test Drugs (Neurotropin or Placebo)	MPQ of each patient is measured after each five-week treatment interval with drug A or drug B.	Assessments of pain severity by the patient using a McGill Pain Questionnaire which consists of 3 major classes of word descriptors-sensory, affective and evaluative - that are used by patients to specify subjective pain experience. Each word chosen from descriptor responses to 20 questions is given a value and the sum of the values of the responses provides a score which is an index of the pain severity with a minimum value of 20 and a maximal value of 78. When it is difficult to recruit the patients, the interim analysis using these data is performed after completion of the study of first 16 patients (target number is 30). The data from 16 patients was analyzed while investigators are blinded to the treatment code (drug A or B) provided by the NIH pharmacy. Only after the analysis was completed was the code unblinded. Placebo or Neurotropin" in place of "drug A or drug B.