Use of Topical Lidocaine to Reduce Pain in Patients With Diabetic Neuropathy

Use of Topical Lidocaine (Lidoderm 5% Patch) to Reduce Pain in Patients With Diabetic Neuropathy: Does the Density and Subtype of Sodium Channels Affect Response?

The purpose of this study is to see if an investigational drug known as the lidocaine 5% patch is safe and effective in reducing the symptoms of diabetic neuropathy, to examine how topical lidocaine affects the nerve endings, and to determine whether treatment with the lidocaine patch can prevent the potential progression to chronic diabetic neuropathy pain in subjects who did not report pain at the start of the study.

Inclusion Criteria:

• Group 1: 18-70 years of age, non-diabetic with no nervous system disease (healthy control group)
• Group 2: 18-70 years of age with Type I or Type II diabetes with significantly painful diabetic neuropathy (VAS > 40mm at Baseline)
• Group 3: 18-70 years of age with Type I or Type II diabetes with non- painful or insignificantly painful diabetic neuropathy (VAS < 40mm at Baseline)

Exclusion Criteria:

• History of clinically significant liver disease, serious peripheral vascular disease, a blood clotting disorder, or any other medical condition felt to be exclusionary by the investigator
• Allergy to lidocaine
• Unwillingness to sign informed consent or any other reasons for which the investigator feels the subject cannot complete the study
• Women who are pregnant, breastfeeding or trying to become pregnant
• History of slow-healing diabetic foot ulcers
• Current skin or soft tissue lesions on the foot that will interfere with application of the lidocaine patch and or skin biopsies
• Subjects taking Class I antiarrhythmics
• HgA1c > 11%
• Active cancer within the previous two years except treated basal cell carcinoma of the skin
• Co-morbidities that can produce neuropathy
• Subjects taking sodium channel blockers within one week of study treatment and throughout the study
• Subjects taking any other experimental drugs within 30 days prior to Screening Visit (Visit 1)
• Application of lidocaine patch to either foot within two weeks of Screening Visit (Visit 1)