NCT04115462

A Relation of Morphine-induced Itch and Pain Processing

A Mechanistic Study on Morphine-induced Orthogonal Neural Plasticity for Itch and Pain Processing in Humans (a Relation of Morphine-induced Itch and Pain Processing)

• Status: Completed
• Phase: N/A
• Study type: Interventional
• Enrollment: 24 (actual)
• Sponsor: Aalborg University · Academic / Other
• Sex: All
• Age: 20 Years – 65 Years
• Healthy volunteers: Accepted

Summary

In This experiment, the investigators would like to test the two following hypotheses regarding the mechanisms by which opioids cause itch: 1. Opioids cause itch by a spinal disinhibition mechanism (central nervous system (CNS) effect). 2. Opioids cause itch through a mast cell-destabilizing effect leading to release of histamine and tryptase in the skin where itch is evoked (peripheral mechanism).

Detailed description

Intrathecal and orally administered opioids are heavily used for the treatment of several acute pain conditions. However, while opioids are effective analgesics for acute pain, they are well-known to frequently cause itch (pruritus) as a side effect according with the two hypotheses stated above. So far, these two hypotheses have never been tested in humans.The present study describes a proposed study design for the purpose of confirming these two hypotheses in parallel in human subjects. Primary endpoints of the study: To evaluate changes itch and pain perception, and superficial perfusion after each itch provocations. Secondary endpoints of the study: To evaluate the existence of a correlation between itch sensitization and analgesic efficacy.

Conditions

• Morphine
• Itch

Interventions

Type	Name	Description
DRUG	Morphine	A 20 mg tablet of morphine
DRUG	Placebo oral tablet	Matching tablet of placebo
DRUG	Histamine	Histaminergic itch will be evoked by a 1% histamine solution. A droplet of histamine solution will be placed on the predetermined area on the forearm, and the SPT lancet will be pierced through the histamine with 120 g of pressure for 1-2 seconds.
DRUG	Cowhage (Mucuna Pruriens)	25 spicules will be inserted in the centre of the predefined skin area on the forearm. The spicules will be gently rubbed for 15-20 seconds in circular motion to facilitate epidermal penetration
DRUG	isotonic saline	A droplet of saline (0.9%) as vehicle control will be placed on the predetermined area on the forearm and the lancet will be pierced through the droplet.
DRUG	Histamine	Histaminergic itch will be evoked by a 1% histamine solution. A droplet of histamine solution will be placed on the predetermined area on the mandibular area, and the SPT lancet will be pierced through the histamine with 120 g of pressure for 1-2 seconds.
DRUG	Cowhage (Mucuna Pruriens)	25 spicules will be inserted in the centre of the predefined skin area on the mandibular area. The spicules will be gently rubbed for 15-20 seconds in circular motion to facilitate epidermal penetration

Timeline

• Start date: 2020-01-15
• Primary completion: 2020-05-01
• Completion: 2020-07-07
• First posted: 2019-10-04
• Last updated: 2020-07-08

Locations

1 site across 1 country: Denmark