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Effects of Lidocaine Patch on Intradermal Capsaicin Induced Pain and Hyperalgesia

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00373893
Recruitment Status : Completed
First Posted : September 8, 2006
Last Update Posted : September 8, 2006
Information provided by:
University of California, San Diego

Brief Summary:
To determine the effects of Lidocaine patch on the pain and hyperalgesia induced by intradermal capsaicin

Condition or disease Intervention/treatment Phase
Pain Hyperalgesia Drug: Lidoderm Patch Phase 1

Detailed Description:
A randomized, double-blinded, placebo controlled methodology will be conducted. At the session subjects will be exposed to placebo patch and lidocaine patch. Prior to study drug administration, a baseline neurosensory test on the volar aspect of both forearms will be performed and baseline vital signs will be measured. A placebo patch and a lidocaine patch will then be applied to the volar aspect of each forearm. The arms will be randomized to which arm receives placebo and which one receives the lidocaine patch. After four hours of application the right forearm patch will be removed the neurosensory testing will be repeated on the right forearm. After completing the testing, capsaicin (10µl, 10 mg/ml) will be injected intradermally on the volar aspect of the right forearm. Elicited and spontaneous pain scores, blood pressure, heart rate, and respiratory rate will be measured at the time of injection and every 2.5 minutes for 10 minutes. A McGill Pain Questionnaire will be administered at the time of capsaicin injection only. Ten minutes after the capsaicin injection, the hyperalgesic area will be established to von Frey hair, stroking, and heat; the flare response will be outlined; and neurosensory testing will performed halfway between the edge of this defined area and the capsaicin injection site. At the completion of the testing on the right forearm, the left forearm patch will be removed and the procedures described for the right forearm will be repeated for the left forearm.

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Study Type : Interventional  (Clinical Trial)
Enrollment : 12 participants
Allocation: Randomized
Intervention Model: Single Group Assignment
Masking: Double
Primary Purpose: Treatment
Official Title: Effects of Lidocaine Patch on Intradermal Capsaicin Induced Pain and Hyperalgesia
Study Start Date : December 2005
Study Completion Date : February 2006

Resource links provided by the National Library of Medicine

Primary Outcome Measures :
  1. Neurosensory testing
  2. Four neurosensory tests: warm and cold sensation,warm/cold pain/touch/mechanical pain.
  3. Warm and cold sensation measured w/a Thermal Sensory
  4. Touch will be measured using von Frey hairs. Calibrated von Frey hairs are filaments of varying size. The filament are selected at random and 3 successive stimuli are applied for 1.5 second at 5 second intervals per filament
  5. Mechanical pain will be measured using von Frey hairs. Endpoint will be pain.

Secondary Outcome Measures :
  1. Allodynia and Hyperalgesia
  2. At the completion of the stimulation, areas of cutaneous allodynia and hyperalgesia will be mapped. The region of hyperalgesia will be established with a 5.18 von Frey hair, and the area of allodynia with a foam brush gently stroked on the skin.

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Age 18 and above

Exclusion Criteria:

  • Pregnancy.
  • Allergy to lidocaine
  • Current painful condition
  • Current use of analgesics for the treatment of pain
  • Lack of ability to understand the experimental protocol and to adequately communicate in English. The neurosensory testing we plan to perform requires the complete cooperation and understanding of the subject. It would be impossible to perform these studies on patients who do not adequately communicate in English.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00373893

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United States, California
UCSD Center for Pain and Palliative Care
La Jolla, California, United States, 92037
Sponsors and Collaborators
University of California, San Diego
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Principal Investigator: Mark S. Wallace, MD University of California, San Diego

Layout table for additonal information Identifier: NCT00373893     History of Changes
Other Study ID Numbers: 051252
First Posted: September 8, 2006    Key Record Dates
Last Update Posted: September 8, 2006
Last Verified: October 2005
Keywords provided by University of California, San Diego:
Additional relevant MeSH terms:
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Somatosensory Disorders
Sensation Disorders
Neurologic Manifestations
Nervous System Diseases
Signs and Symptoms
Anesthetics, Local
Central Nervous System Depressants
Physiological Effects of Drugs
Sensory System Agents
Peripheral Nervous System Agents
Anti-Arrhythmia Agents
Voltage-Gated Sodium Channel Blockers
Sodium Channel Blockers
Membrane Transport Modulators
Molecular Mechanisms of Pharmacological Action
Dermatologic Agents