Evaluation of Peripheral Itch Mechanisms Following Injection of Morphine

Effect of Intradermal Morphine Application on Histaminergic and Non-histaminergic Itch and Related TRPV1 and Antihistamine Treatment

The aim of this study is to the effect of opioid (morphine) intradermal application on histaminergic and non-histaminergic itch. In particular, we would like to demonstrate that also peripheral administration of morphine may affect mast cell release of histamine.

Study Overview

• Status: Completed
• Conditions: Morphine; Histamine; Cowhage; Isotonic Saline
• Intervention / Treatment: Drug: Morphine

Detailed Description

Opioids (i.e. substances extracted from opium poppies, e.g. morphine) are used for treatment of both acute and chronic pain conditions as well as in surgical procedures. Opioids render effective pain relief, however, they may cause bothersome itch as a side effect. With this series of experiments, we wish to clarify how an injection with morphine in the skin layer called dermis (located right below the upper skin) will affect itch.

• Study Type: Interventional
• Enrollment (Actual): 26
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Denmark
  • Nordjylland
    • Aalborg, Nordjylland, Denmark, 9229
      • Silvia Lo Vecchio

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 60 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

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 Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Morphine; During the 1st session, each of the middle forearms of the subject will be divided into two squared areas (4x4 cm) located 3 cm apart. Two areas will be treated with an intradermal injection of morphine (0.05 ml, 0.1 mg/ml), while two areas will be treated with injections of isotonic saline (0.05 ml, 0.9%) as vehicle. Fifteen minutes after the injections, the measurement of FLPI and wheal size will be conducted in one morphine and one saline treated area. This measurement will be followed by application of histamine and cowhage in the four areas (two pre-treated with morphine and two pre-treated with vehicle)

Drug: Morphine; During the 1st session, each of the middle forearms of the subject will be divided into two squared areas (4x4 cm) located 3 cm apart. Two areas will be treated with an intradermal injection of morphine (0.05 ml, 0.1 mg/ml), and two areas with an intradermal injection of isotonic saline.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Measuring itch 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".	10 minutes
Measuring pain 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".	10 minutes
Superficial blood perfusion measurement	Superficial blood perfusion is measured by a Speckle contrast imager	15 minutes

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
While size	While size will be assessed with a ruler	15 minutes

Collaborators and Investigators

• Sponsor: Aalborg University

Study record dates

Study Major Dates

• Study Start (Actual): July 1, 2021
• Primary Completion (Actual): May 31, 2022
• Study Completion (Actual): December 31, 2022

Study Registration Dates

• First Submitted: December 14, 2020
• First Submitted That Met QC Criteria: December 14, 2020
• First Posted (Actual): December 17, 2020

Study Record Updates

• Last Update Posted (Actual): January 18, 2023
• Last Update Submitted That Met QC Criteria: January 16, 2023
• Last Verified: January 1, 2023

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Central Nervous System Depressants; Peripheral Nervous System Agents; Analgesics; Sensory System Agents; Analgesics, Opioid; Narcotics; Morphine
• Other Study ID Numbers: N-20200084

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No