Evaluation of Peripheral Itch Mechanisms Following Injection of Morphine (Second Sub-Project)

NCT04700007 | Completed DMC

• 1 other identifier: N-20200084 2nd sub-project
• Study Type: interventional
• Target: 26
• Locations: 1 country
• Sites: 1

Brief Summary

The aim of our 2nd sub-project is to clarify if the capsaicin receptor TRPV1 is implicated in the mechanism of morphine-induced mast cell degranulation. Moreover, we also aim to clarify if the mechanism of opioid-induced itch relay on the histaminergic pathway by using the antihistamine (diphenhydramine) to suppress the release of histamine from peripheral mast cells.

Conditions

Itch

Outcome Measures

Primary Outcomes (3)

• Measuring itch intensity by computerized Visual Analog Scale Scoring

  We will ask the subjects to rate the sensation of itch on a 100 mm VAS scale ranging from 0 to 100 where 0 indicates "no itch" and 100 indicates "worst itch imaginable".

  For 10 minutes

• Measuring pain intensity by computerized Visual Analog Scale Scoring

  We will ask the subjects to rate the sensation of pain on a 100 mm VAS scale ranging from 0 to 100 where 0 indicates "no pain" and 100 indicates "worst pain imaginable".

  For 10 minutes

• Superficial blood perfusion measurement

  Superficial blood perfusion is measured by a Speckle contrast imager

  After 15 minutes

Secondary Outcomes (1)

• While size

  After 15 minutes

Study Arms (1)

Study group

EXPERIMENTAL

Drug: Capsaicin; Drug: Diphenhydramine; Drug: Morphine Chloride; Drug: Isotonic saline; Drug: Histamine

Interventions

Capsaicin DRUG

A capsaicin patch will be applied on a 3x3 cm squared area on the volar forearm. The patch will be left in place for 24h after which it will be removed.

Study group

Diphenhydramine DRUG

Diphenhydramin cream 1% (Restamine®) will be applied on a 3x3 cm squared predetermined area on the volar forearm for 24 hours.

Also known as: Antihistamine

Study group

Morphine Chloride DRUG

Morphine solution (0.1mg/ml, Morphine Hydrochloride) 50 μl will be applied intradermally to the center of a predetermined area on the volar forearm by a 1 ml syringe.

Study group

Isotonic saline DRUG

injections of isotonic saline (0.05 ml, 0.9%) as vehicle will be performed.

Study group

Histamine DRUG

A small drop of histamine dihydrochloride (1%, in saline) will be applied to a previously determined area on the volar forearm followed by a prick through the drop.

Study group

Eligibility Criteria

• Age: 18 Years - 60 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Healthy men and women
• years
• Speak and understand English

You may not qualify if:

• Participants with any clinically significant abnormalities that in the opinion of the investigator may increase the risk associated with trial participation or may interfere with the interpretation of the trial results.
• Pregnancy or lactation
• Drug addiction defined as any use of cannabis, opioids or other addictive drugs
• Lack of ability to cooperate
• Current use of medications that may affect the trial such as antihistamines, antipsychotics and pain killers as well as systemic or topical steroids.
• Participants with known allergy/discomfort to the opioid morphine and antihistamine.
• Skin diseases
• Moles, scars or tattoos in the area to be treated or tested.
• Consumption of alcohol or painkillers 24 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)

Sponsors & Collaborators

• Aalborg University: lead

Study Sites (1)

Mech-Sense, Medicinsk Gastroenterologisk ambulatorium, Medicineshus, Aalborn Universitethospitalet

Aalborg, North Denmark, 9000, Denmark

Location

MeSH Terms

Conditions

Pruritus

Interventions

Capsaicin; Diphenhydramine; Histamine Antagonists; Morphine; Sodium Chloride; Histamine

Condition Hierarchy (Ancestors)

Skin Diseases; Skin and Connective Tissue Diseases; Skin Manifestations; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Intervention Hierarchy (Ancestors)

Polyunsaturated Alkamides; Amides; Organic Chemicals; Alkenes; Hydrocarbons, Acyclic; Hydrocarbons; Catechols; Phenols; Benzene Derivatives; Hydrocarbons, Aromatic; Hydrocarbons, Cyclic; Solanaceous Alkaloids; Alkaloids; Heterocyclic Compounds; Fatty Acids, Monounsaturated; Fatty Acids, Unsaturated; Fatty Acids; Lipids; Ethylamines; Amines; Benzhydryl Compounds; Histamine Agents; Neurotransmitter Agents; Molecular Mechanisms of Pharmacological Action; Pharmacologic Actions; Chemical Actions and Uses; Physiological Effects of Drugs; Morphine Derivatives; Morphinans; Opiate Alkaloids; Heterocyclic Compounds, Bridged-Ring; Heterocyclic Compounds, 4 or More Rings; Heterocyclic Compounds, Fused-Ring; Phenanthrenes; Polycyclic Aromatic Hydrocarbons; Polycyclic Compounds; Chlorides; Hydrochloric Acid; Chlorine Compounds; Inorganic Chemicals; Sodium Compounds; Biogenic Monoamines; Biogenic Amines; Imidazoles; Azoles; Heterocyclic Compounds, 1-Ring; Autacoids; Inflammation Mediators; Biological Factors

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: PhD, Assistant Professor

Study Record Dates

• First Submitted: January 6, 2021
• First Posted: January 7, 2021
• Study Start: January 18, 2021
• Primary Completion: December 31, 2021
• Study Completion: December 31, 2021
• Last Updated: January 27, 2022

Record last verified: 2022-01

Locations

DK (1)