The Role of Intravenous (IV) Lidocaine in the Management of Chronic Neuropathic Pain of Peripheral Nerve Origin

• Hospital Anxiety and Depression Scale [ Time Frame: obtained baseline, 24 and 72 hours and then weeks 1,2,3, and 4 ] [ Designated as safety issue: No ]
• Modified Brief Pain Inventory [ Time Frame: obtained baseline, 24, 72 hours and then weeks 1,2,3 and 4 ] [ Designated as safety issue: No ]
• Leeds Sleep Evaluation Questionnaire [ Time Frame: obtained baseline, 24, 72 hours and then weeks 1,2,3 and 4 ] [ Designated as safety issue: No ]
• Patient Global Satisfaction with Treatment and Impression of Change [ Time Frame: obtained baseline, 24, 72 hours and then weeks 1,2,3 and 4 ] [ Designated as safety issue: No ]
• Side Effects [ Time Frame: obtained baseline, 24, 72 hours and then weeks 1,2,3 and 4 ] [ Designated as safety issue: No ]
• Quality of Life Health Outcome Instrument [ Time Frame: obtained baseline, 24, 72 hours and then weeks 1,2,3 and 4 ] [ Designated as safety issue: No ]

Pain as a result of nerve injury (neuropathic pain) is a particularly severe form of chronic pain. Common examples of neuropathic pain are pain due to diabetes and shingles. There is good evidence that an intravenous infusion of lidocaine (local anesthetic) is useful for the management of neuropathic pain in the short term - up to six hours.

This study will examine the role of intravenous lidocaine in the relief of neuropathic pain over four weeks following infusion compared to a salt water infusion. If we can show that intravenous lidocaine provides sustained benefit for up to one month, this will be a major advance in the management of individuals suffering from neuropathic pain.

• Drug: Lidocaine
  Lidocaine 5 mg/kg in 250 ml of normal saline infused over 45 minutes.
  Other Name: Xylocaine
• Drug: Diphenhydramine
  Diphenhydramine 50 mg in 250 ml of normal saline infused over 45 minutes.
  Other Name: Benadryl

• Placebo Comparator: Diphenhydramine(Benadryl)
  Intervention: Drug: Diphenhydramine
• Active Comparator: Lidocaine
  Intervention: Drug: Lidocaine

Inclusion Criteria:

• Chronic neuropathic pain of peripheral nerve origin as determined by the study physician and a score of 4/10 or greater on the DN4 questionnaire.
• Moderate to severe pain as defined by screening average pain intensity of 5 or greater on a 0-10 numerical rating scale.
• Neuropathic pain duration of at least 6 months.

Exclusion Criteria:

• Presence of clinically significant cardiac disease.
• Poorly controlled seizure disorder.
• Significant psychiatric disorder.
• History of allergy to lidocaine or any other amide local anesthetic
• History of allergy to diphenhydramine.
• Prior treatment with a local anesthetic infusion.
• Neuropathic pain due to cancer or complex regional pain syndrome
• Language barrier or cognitive impairment that would preclude understanding of the study and filling out of questionnaires
• Lack of a driver to transport the patient to and from the pain clinic.