Antipruritic Effect of Topical Ketamine, Amitriptyline, and Lidocaine

Brief Summary

The purpose of this study is to examine the antipruritic efficacy of topical ketamine, amitriptyline, lidocaine, and a tri-combination of ketamine, amitriptyline and lidocaine (hereafter referred to as "KeAmLi") using non-histaminergic itch provocations in healthy volunteers. The primary outcome is itch reduction (AUC) between the vehicle and active treatment (KeAmLi-combo). Secondary outcomes include modality-specific analgesic properties of the topically applied ketamine, amitriptyline, lidocaine, and KeAmLi-combo to controlled quantitative thermal and mechanical stimuli, which can improve our understanding of the mechanism of action of these substances in the context of topical therapy.

Intervention / Treatment

The antipruritic effect of 4 topical treatments and 1 vehicle treatment will be explored in each subject. Study visit 1 will consist of testing 3 topical formulations, and study visit 2 will test the remaining 2 topical formulations in each subject.
  • Ketamine Hydrochloride (DRUG)
    2g of topical 10% Ketamine will be applied for 30 minutes on one 4x4cm area on the volar forearm in one of two study visits.
  • Amitriptyline Hydrochloride (DRUG)
    2g of topical 5% Amitriptyline will be applied for 30 minutes on one 4x4cm area on the volar forearm in one of two study visits.
  • Lidocaine Hydrochloride (DRUG)
    2g of topical 5% Lidocaine will be applied for 30 minutes on one 4x4cm area on the volar forearm in one of two study visits.
  • Ketamine hydrochloride, Amitriptyline hydrochloride, and Lidocaine hydrochloride (COMBINATION_PRODUCT)
    2g of topical KeAmLi-combo (ketamine 10%, amitriptyline 5%, and lidocaine 5%) will be applied for 30 minutes on one 4x4cm area on the volar forearm in one of two study visits.
  • Lipoderm Cream (DRUG)
    2g of topical vehicle (Lipoderm) will be applied for 30 minutes on one 4x4cm area on the volar forearm in one of two study visits.

Condition or Disease

  • Pruritus

Phase

  • Phase 2
  • Study Design

    Study type: INTERVENTIONAL
    Status: Terminated
    Study results: No Results Available
    Age: 18 Years to 50 Years
    Enrollment: 13 (ACTUAL)
    Funded by: Other
    Allocation: Randomized
    Primary Purpose: Treatment

    Masking

    DOUBLE:
    • Participant
    • Investigator

    Clinical Trial Dates

    Start date: May 23, 2017 ACTUAL
    Primary Completion: Jul 19, 2017 ACTUAL
    Completion Date: Jul 21, 2017 ACTUAL
    Study First Posted: Mar 30, 2017 ACTUAL
    Results First Posted: Jul 02, 2019 ACTUAL
    Last Updated: Jun 24, 2019

    Sponsors / Collaborators

    Lead Sponsor: Gil Yosipovitch
    Responsible Party: Gil Yosipovitch

    This is a double-blind, vehicle-controlled study to evaluate the antipruritic efficacy of topical ketamine, amitriptyline, lidocaine, and a tri-combination of ketamine, amitriptyline and lidocaine (hereafter referred to as "KeAmLi") using non-histaminergic itch provocations in healthy volunteers. Each participant will be pre-treated with the vehicle and 4 active topical creams, over two study visits (3 treatments on the 1st visit and 2 treatment on the 2nd visit). Each treatment will be applied to the randomized forearm test area for 30 minute, and then sensory testing will be performed. Sensory testing includes thermal and mechanical stimuli, and itch induction using the plant cowhage. These tests will reveal mechanistic information and potential cellular and molecular targets for improved antipruritic and analgesic therapies.

    Participant Groups

    • Topical KeAmLi-combo (ketamine 10%, amitriptyline 5%, and lidocaine 5%) will be applied to one four 4 x 4 cm predefined skin areas on the ventral forearms during one of two study visits. The pre-treatment will occur under topical occlusion for 30 minutes to allow the ointment to be adsorbed. Following this, residual ointment will be removed and sensory testing, strictly within the pretreated area, will commence.

    • Topical ketamine 10% will be applied to one four 4 x 4 cm predefined skin areas on the ventral forearms during one of two study visits. The pre-treatment will occur under topical occlusion for 30 minutes to allow the ointment to be adsorbed. Following this, residual ointment will be removed and sensory testing, strictly within the pretreated area, will commence.

    • Topical amitriptyline 5% will be applied to one four 4 x 4 cm predefined skin areas on the ventral forearms during one of two study visits. The pre-treatment will occur under topical occlusion for 30 minutes to allow the ointment to be adsorbed. Following this, residual ointment will be removed and sensory testing, strictly within the pretreated area, will commence.

    • Topical lidocaine 5% will be applied to one four 4 x 4 cm predefined skin areas on the ventral forearms during one of two study visits. The pre-treatment will occur under topical occlusion for 30 minutes to allow the ointment to be adsorbed. Following this, residual ointment will be removed and sensory testing, strictly within the pretreated area, will commence.

    • Topical vehicle (PCCA Lipoderm) will be applied to one four 4 x 4 cm predefined skin areas on the ventral forearms during one of two study visits. The pre-treatment will occur under topical occlusion for 30 minutes to allow the ointment to be adsorbed. Following this, residual ointment will be removed and sensory testing, strictly within the pretreated area, will commence.

    Eligibility Criteria

    Sex: All
    Minimum Age: 18
    Maximum Age: 50
    Age Groups: Adult
    Healthy Volunteers: Yes

    Inclusion Criteria:

    1. Healthy subjects (absence of disease) between 18 and 50 years of age.
    2. Must be in general good health with no disease or physical conditions that would impair evaluation of itch and pain perception.
    3. No history of chronic itch or pain.
    4. Must abstain from the use of any systemic or topical anti-histamine, steroid, or pain relief medications 48 hours prior to the study visits.
    5. Must abstain from the use of moisturizers on the arms the day of study visit.

    Exclusion Criteria:

    1. Individuals under 18 or over 50 years of age.
    2. Inability to complete the required measures.
    3. The presence of an itchy skin disease or a painful condition.
    4. Diagnosis of diseased that would affect itch or pain perception (e.g. neuropathies).
    5. Currently enrolled in any investigational study in which the subject is receiving any type of drug, biological, or non-drug therapy.
    6. Use of oral, topical analgesics, or other medications known to interfere with itch or pain perception 48 hours prior to the study visits (e.g. antihistamines, anesthetics, anti-inflammatories, opioids, neuroleptics, etc.).
    7. Use of emollients on the volar aspects of the forearms arms on the day of the study visit.
    8. Use of anti-depressants, anti-psychotics, and illicit drugs.
    9. Known history of neuropathy, uremia, uncontrolled thyroid disease, and diabetes mellitus.
    10. Known history of anaphylactic shock, or allergy to cowhage and/or known adverse reactions to lidocaine (or other local anesthetics of the amide type), ketamine or amitriptyline.

    Primary Outcomes
    • Peak itch intensity between the vehicle and 4 other active treatments (individual ketamine, amitriptyline, or lidocaine, and KeAmLi-combo). Itch intensity was measured on a 100mm scale visual analog scale for 10 minutes. 0 was weighted with "no itch" and 100 was weighted with "most itch imaginable".

    Secondary Outcomes
    • Two standardized quantitative sensory tests are performed to measure warmth detection threshold (assesses the threshold of which warmth sensation is first detected) and heat pain threshold (assesses the threshold at which heat pain sensation is first detected). Measured in change in celsius.

    • Assess mechanical detection and pain thresholds using von Frey filaments stimulators (measured in force mN) to calculate the final threshold as the geometric mean of five series of ascending and descending stimuli.

    More Details

    NCT Number: NCT03096444
    Other IDs: 20170087
    Study URL: https://clinicaltrials.gov/study/NCT03096444
    Last updated: Sep 29, 2023