Working…
ClinicalTrials.gov
ClinicalTrials.gov Menu

A Mechanistic Evaluation of the Nociceptive Desensitizing Properties of Topical Capsaicin

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. Know the risks and potential benefits of clinical studies and talk to your health care provider before participating. Read our disclaimer for details.
 
ClinicalTrials.gov Identifier: NCT03587220
Recruitment Status : Recruiting
First Posted : July 16, 2018
Last Update Posted : May 10, 2019
Sponsor:
Information provided by (Responsible Party):
Silvia Lo Vecchio, Aalborg University

Brief Summary:
The aim of this project is to study the role of transient receptor potential (TRP-) channel V1 (TRPV1+) fibers in the development of cutaneous inflammation induced by epidermal Ultraviolet-B damage. Moreover, in this project the investigators want to evaluate if the capsaicin-desensitization action can still be induced in a skin area pretreated with topical, local anesthetic lidocaine.

Condition or disease Intervention/treatment Phase
Capsaicin Ultaviolet B Light Burn Neuropathic Pain Lidocaine Drug: Capsaicin Topical Radiation: Ultraviolet-B (UVB) irradiation Other: Histamine 1% Drug: Lidocaine Not Applicable

Detailed Description:
In this project the Ultraviolet- B pain model, a model using type B ultraviolet rays to induce a first-degree sunburn, will be used to induce a non-specific inflammation in the skin. This model is well-known to produce both peripheral and central hyperalgesia through sensitization of peripheral and central nociceptors. Capsaicin, the active substance in chili peppers, is currently used to treat peripheral neuropathic pain, and prolonged application of 8% capsaicin patch causes profound desensitization to painful heat stimuli and itch provocations. Therefore, the investigators would like to monitor the development of unspecific UVB-cutaneous inflammation and consequent neurogenic flare in a capsaicin pre-treated area. Moreover the investigators want to test if pre-treating the skin with lidocaine can reduce the pain associated with the capsaicin application without affecting its desensitization action.

Layout table for study information
Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 44 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single (Participant)
Primary Purpose: Basic Science
Official Title: En undersøgelse af Mekanismerne Bag Nociceptiv Desensibilisering forårsaget af Topikal Capsaicin
Actual Study Start Date : August 1, 2018
Estimated Primary Completion Date : December 31, 2019
Estimated Study Completion Date : December 31, 2020

Resource links provided by the National Library of Medicine

Drug Information available for: Capsaicin

Arm Intervention/treatment
Experimental: Capsaicin+UVB group
All subjects will be treated with capsaicin, placebo + UVB, or Capsaicin+UVB.
Drug: Capsaicin Topical
Capsaicin patches (dosage form: patch 8% Qutenza) will be applied on 4x4 cm squared areas on the volar forearm. The patches will be left in place for 24h and 3 hours after which they will be removed.

Radiation: Ultraviolet-B (UVB) irradiation
Two circular areas (Ø 2 cm) on the forearm are irradiated with 2 x MED (Minimal Erythema Dose) dose of UVB using a calibrated UVB machine (290-320nm wavelength), Saal Mann Multi Tester (Mann Saal, LT SBC 400 Herford, Germany).

Experimental: Capsaicin + EMLA group
All subjects will be pre-treated with lidocain cream before capsaicin application
Drug: Capsaicin Topical
Capsaicin patches (dosage form: patch 8% Qutenza) will be applied on 4x4 cm squared areas on the volar forearm. The patches will be left in place for 24h and 3 hours after which they will be removed.

Other: Histamine 1%
To deliver histamine, standard allergy skin prick test (SPT) lancets are applied. The lancets have a 1 mm shouldered tip adapt to introduce a small amount of test substance extremely locally and approximately at the dermo-epidermal junction.

Drug: Lidocaine
Cutaneous anaesthesia will be topically induced by using EMLA cream 5%, a local anaesthetic cream consisting of equal parts of lidocaine and prilocaine (1g contains 25 mg of lidocaine and 25 mg of prilocaine)




Primary Outcome Measures :
  1. Superficial blood perfusion measured by a Speckle contrast imager (FLPI, Moor Instruments, England). [ Time Frame: Changes from baseline to 7 days after intervention ]
  2. Measurement of Warm Detection Thresholds and Heat thresholds by using a PATHWAY ATS (Medoc Ltd, Israel) thermal sensory testing device. [ Time Frame: Changes from baseline to 7 days after intervention ]
  3. Measurement of Pain to Supra-threshold Heat Stimuli by using a PATHWAY ATS (Medoc Ltd, Israel) thermal sensory testing device. [ Time Frame: Changes from baseline to 7 days after intervention ]
  4. Measurement of Mechanical Pain Thresholds and Sensitivity using a pin-prick set consisting of 8 needles each having a diameter of 0.6 mm and different force applications: 0.8, 1.6, 3.2, 6.4, 12.8, 25.6, 50.1 and 60.0 g. [ Time Frame: Changes from baseline to 7 days after intervention ]
  5. Trans-epidermal Water Loss (TEWL) using a 2x2 cm probe to measure the humidity gradient of the skin. [ Time Frame: Changes from baseline to 7 days after intervention ]

Secondary Outcome Measures :
  1. assessment of pain rating by using a visual analog scales (VAS) [ Time Frame: Change from baseline to 24 h ]
    The subject will report the peak and average of the perceived pain sensation during the last 24 hours (on a VAs scale from 0 indicating 'no pain' to100 indicating 'worst imaginable pain').

  2. Itch rating by using a visual analog scales (VAS) [ Time Frame: Changes from baseline to 7 days after intervention ]
    Itch is monitored for 9 minutes using a visual analog scale from 0 indicating 'no itch' to100 indicating 'worst imaginable itch.



Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.


Layout table for eligibility information
Ages Eligible for Study:   18 Years to 60 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion criteria:

  • Healthy men and women
  • 18-60 years
  • Caucasian descent (only in sub-study 1)
  • Speak and understand English

Exclusion criteria:

  • Pregnancy or lactation
  • Drug addiction defined as any use of cannabis, opioids or other drugs
  • Previous or current neurologic, musculoskeletal or mental illnesses
  • Lack of ability to cooperate
  • Current use of medications that may affect the trial
  • Skin diseases
  • Consumption of alcohol or painkillers 24 hours before the study days and between these
  • Moles or tattoos in the area to be treated or tested.
  • Exposure of the irradiated area to UV radiation (e.g., sun) 48 hours before the study days and between these
  • Acute or chronic pain
  • Participation in other trials within 1 week of study entry (4 weeks in the case of pharmaceutical trials)
  • Known history of anaphylactic shock, or local allergy (contact dermatitis) to lidocaine, prilocaine or other local anaesthetics of the amide type.

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 ClinicalTrials.gov identifier (NCT number): NCT03587220


Contacts
Layout table for location contacts
Contact: Silvia Lo Vecchio, PhD 21397785 slv@hst.aau.dk

Locations
Layout table for location information
Denmark
Silvia Lo Vecchio Recruiting
Aalborg, Nordjylland, Denmark, 9000
Contact: Silvia Lo Vecchio, PhD    21397785    slv@hst.aau.dk   
Sponsors and Collaborators
Aalborg University

Layout table for additonal information
Responsible Party: Silvia Lo Vecchio, Biologist, PhD, Aalborg University
ClinicalTrials.gov Identifier: NCT03587220     History of Changes
Other Study ID Numbers: N-20180034
First Posted: July 16, 2018    Key Record Dates
Last Update Posted: May 10, 2019
Last Verified: May 2019

Layout table for additional information
Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No
Additional relevant MeSH terms:
Layout table for MeSH terms
Neuromuscular Diseases
Lidocaine
Neuralgia
Peripheral Nervous System Diseases
Nervous System Diseases
Pain
Neurologic Manifestations
Signs and Symptoms
Capsaicin
Histamine
Histamine phosphate
Anesthetics, Local
Anesthetics
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
Antipruritics
Dermatologic Agents
Histamine Agonists
Histamine Agents
Neurotransmitter Agents