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

Itch Clinical Trial

Official title:

Effect of Intradermal Morphine Application on Histaminergic and Non-histaminergic Itch and Related TRPV1 and Antihistamine Treatments (2nd Sub-project)

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT04700007
• Other study ID #: N-20200084 2nd sub-project
• Status: Completed
• Phase: N/A
• Start date: January 18, 2021
• Est. completion date: December 31, 2021

Study information

• Verified date: January 2022
• Source: Aalborg University
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial 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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 26
• Est. completion date: December 31, 2021
• Est. primary completion date: December 31, 2021
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 18 Years to 60 Years

Eligibility

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)

Related Conditions & MeSH terms

• Itch

Intervention

Drug:
• Capsaicin
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.
• Diphenhydramine
Diphenhydramin cream 1% (Restamine®) will be applied on a 3x3 cm squared predetermined area on the volar forearm for 24 hours.
• Morphine Chloride
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.
• Isotonic saline
injections of isotonic saline (0.05 ml, 0.9%) as vehicle will be performed.
• Histamine
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.

Locations

Country	Name	City	State
Denmark	Mech-Sense, Medicinsk Gastroenterologisk ambulatorium, Medicineshus, Aalborn Universitethospitalet	AAlborg	Nordjylland

Sponsors (1)

Lead Sponsor	Collaborator
Aalborg University

Country where clinical trial is conducted

Denmark, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	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
Primary	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
Primary	Superficial blood perfusion measurement	Superficial blood perfusion is measured by a Speckle contrast imager	After 15 minutes
Secondary	While size	While size will be assessed using a ruler	After 15 minutes