A Study of Intra-dermal Injection of Botulinum Toxin Type A for the Diabetic Neuropathic Foot Pain

Sponsor

Taipei Medical University Hospital (Other)

Overall Status

Completed

CT.gov ID

NCT00336349

Collaborator

Allergan (Industry)

Enrollment

Location

Duration (Months)

1.7

Patients Per Site Per Month

Study Details

Study Description

Brief Summary

Effective treatment of neuropathic foot pain in diabetic patients is very important to improve their quality of life. There are many medications used to reduce the diabetic neuropathic pain, including anticonvulsants, anti-depressants or analgesics, but none is universally satisfied. A few previous studies employing BOTOX® i.d. injection for control of trigeminal neuralgia, post-herpes neuralgia indicate that BOTOX® was effective in controlling neuropathic pain. Intradermal injection of BOTOX® to the dorsum of the foot in diabetics should be effective in controlling diabetes-associated polyneuropathic pain of the foot.

Condition or Disease	Intervention/Treatment	Phase
Diabetes Mellitus Neuropathic Pain	Drug: Botulinum Toxin Type A	N/A

Detailed Description

Design: The present study is a single-center, randomized, double-blinded, cross-over study of BOTOX® in diabetic neuropathic foot pain.

Pain Assessment: Subjective intensity of neuropathic pain was rated by a 100 mm visual analogue scale (VAS, 0 = no pain, 100 = unbearable pain). To assess the somatosensory effect of botulinum toxin, we also performed aserial somatosensory evaluations upon bilateral medial (L5 dermatome) and lateral (S1 dermatome) dorsum of the feet, and bilateral medial calves (L4 dermatome). Tactile threshold (TT) values of were assessed by von Frey filament, applied in an ascending and descending order of magnitude. The force required to bend the filaments was converted to log units for further comparison. Pain threshold (PT) to static mechanical stimuli was also determined by von Frey filament upon the above test sites to evaluate the severity of cutaneous allodynia. All subjects underwent the subjective pain rating and somatosensory evaluations (TT and PT) at baseline and each follow-up stage.

Treatment: Treatments will consist of intradermal (i.d). injections of BOTOX® after topical anesthesia over randomly selected 15 patients and saline placebo over the other 15 patients. Dose will be 0.5-1U/cm2 BOTOX®, at total dose of 50 U/foot. A follow-up visit and assessment will be performed at 1, 4 8, 12 weeks following treatment during which the previous tests will be repeated. A cross-over of injection in the Botox group and saline group will be taken at the 12th week and then repeat the assessments at 1, 4, 8, 12 weeks.

Analysis: Comparison between treated feet and non-treated feet based on QVAS and pain sensitivity test and life quality questionnaire by chi-square analysis.

The summary of proposal is as below. Botox: 1. intradermal injection after Topical anesthesia, EMLA 2. 1 cc syringe with 30-gauge needle 3. 50 U/foot 4. 12 points/foot (3×4) A total of 30 cases (15 Botox group, 15 saline group and cross-over 12 weeks later)

Study Design

Study Type:

Interventional

Actual Enrollment :

30 participants

Allocation:

Randomized

Intervention Model:

Crossover Assignment

Masking:

Double

Primary Purpose:

Treatment

Official Title:

A Study of Intra-dermal Injection of Botulinum Toxin Type A for the Diabetic Neuropathic Foot Pain

Study Start Date :

Jun 1, 2006

Actual Primary Completion Date :

Dec 1, 2007

Actual Study Completion Date :

Dec 1, 2007

Outcome Measures

Primary Outcome Measures

VAS of pain []

Secondary Outcome Measures

SF36 for life quality []
sleep quality []
blood flow of feet []

Eligibility Criteria

Criteria

Ages Eligible for Study:

30 Years and Older

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

Inclusion Criteria:

type 2 diabetes with medication for diabetes> 3 years (established diagnosis, HbA1C<10% )
symptomatic polyneuropathy (stocking distribution and tingling pain)
stable but not satisfactory effects of drugs for diabetic neuropathic foot pain (stable effects of medication for over 6 months)
fitness of polyneuropathy on Nerve Conduction Velocity (NCV) criteria
willing and able to give written informed consent.
willing and able to complete the entire study course and comply with study directions.

Exclusion Criteria:

Injection not possible due to physiologic barriers.
Subject is pregnant or lactating.
Females of childbearing age who are not using a reliable method of avoiding pregnancy.
Significant medical or psychiatric disease.
Any condition that may put the subject at increased risk with exposure to BOTOX®, including
diagnosed myasthenia gravis, Eaton-Lambert syndrome, amyotrophic lateral sclerosis, or any other disease that might interfere with neuromuscular function.
Use of aminoglycoside antibiotics, curare-like agents, or other agents that might interfere with neuromuscular function.
Acute medication overuse in the investigator's best judgment.
Alcohol or drug abuse.
Heavy smokers
Infection or skin problems at any of the injection sites.
Known allergy or sensitivity to the study medications or its components.
Injections of anesthetics or steroids into the study targeted muscles within one month prior to the day of injection
Concurrent participation in another clinical trial within 30 days of the beginning of this study.
Previous use of botulinum toxin. (Types A or B)
Profound atrophy or excessive weakness of the muscles in the target area(s) or injection.
Evidence of peripheral artery occlusion
Evidence of liver or renal function impairment
Evidence old stroke