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

Not Applicable

Completed

• Conditions: Itch
• Interventions: Drug: Capsaicin; Drug: Diphenhydramine; Drug: Morphine Chloride; Drug: Isotonic saline; Drug: Histamine

• Registration Number: NCT04700007
• Lead Sponsor: Aalborg University

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.

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2021-01-06
• Study First Submitted QC: 2021-01-06
• Study First Posted: 2021-01-07
• Study Start: 2021-01-18
• Primary Completion: 2021-12-31
• Study Completion: 2021-12-31
• Status Verified: 2022-01
• Last Update Submitted: 2022-01-26
• Last Update Posted: 2022-01-27

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 26

Inclusion Criteria

• Healthy men and women
• 18-60 years
• Speak and understand English

Exclusion Criteria

• 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)

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
Study group	Capsaicin	-
Study group	Isotonic saline	-
Study group	Morphine Chloride	-
Study group	Diphenhydramine	-
Study group	Histamine	-

Primary Outcome Measures

Name	Time	Method
Measuring itch intensity by computerized Visual Analog Scale Scoring	For 10 minutes	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".
Measuring pain intensity by computerized Visual Analog Scale Scoring	For 10 minutes	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".
Superficial blood perfusion measurement	After 15 minutes	Superficial blood perfusion is measured by a Speckle contrast imager

Secondary Outcome Measures

Name	Time	Method
While size	After 15 minutes	While size will be assessed using a ruler

Trial Locations

Locations (1)

Mech-Sense, Medicinsk Gastroenterologisk ambulatorium, Medicineshus, Aalborn Universitethospitalet; 🇩🇰 AAlborg, Nordjylland, Denmark