An interventional study of Morphine and Placebo oral tablet in Morphine and Itch, sponsored by Aalborg University. Completed at 1 site in Denmark. Open to participants aged 20 Years to 65 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2020-07-08.
Sponsored by Aalborg University · Not applicable, Interventional, and Basic science
In This experiment, the investigators would like to test the two following hypotheses regarding the mechanisms by which opioids cause itch:
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.
Aalborg University is the lead sponsor of 178 studies on the registry; 37 are open to participants now.
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Exclusion Criteria:
Each participant will receive a single dose of 20 mg morphine tablet. At estimated peak-plasma concentration testing is conducted. The subject and the assessor are both blinded to the drug administrations.
Drug: Morphine · Drug: Histamine · Drug: Cowhage (Mucuna Pruriens) · Drug: isotonic saline
Each participant will receive a single dose of an identical placebo tablet. At estimated peak-plasma concentration testing is conducted. The subject and the assessor are both blinded to the drug administrations.
Drug: Placebo oral tablet · Drug: Histamine · Drug: Cowhage (Mucuna Pruriens) · Drug: isotonic saline
A 20 mg tablet of morphine
Matching tablet of placebo
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.
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
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.
Also known as: saline
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.
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
Microvascular reactivity
The evoked cutaneous inflammation (quantified by superficial blood perfusion) will be measured by full-field laser perfusion imaging.
Time frame: Before and 70 minutes after morphine/placebo administration
Microvascular reactivity
The evoked cutaneous inflammation (quantified by superficial blood perfusion) will be measured by full-field laser perfusion imaging.
Time frame: 10 minutes after every itch inductions
Assessment of itch
Immediately following the itch provocations, participants will be instructed to rate the itch intensity for 10 minutes using a digital visual analogue scale (VAS; eVAS Software: Aalborg, University, Denmark), on a tablet. The scale will be measured from 0 to 100, where 0 represents 'no itch' and 100 'worst itch imaginable'.
Time frame: 1 minute after every itch inductions
Assessment of pain
Immediately following the itch provocations, participants will be instructed to rate the pain intensity for 10 minutes using a digital visual analogue scale (VAS; eVAS Software: Aalborg, University, Denmark), on a tablet. The scale will be measured from 0 to 100, where 0 represents 'no pain' and 100 'worst pain imaginable'.
Time frame: 1 minute after every itch inductions
Cold (CPT) and heat (HPT) pain thesholds
Thermal cold and heat stimuli will be applied by a contact heat-evoked potential stimulator (PATHWAYS; Medoc Ltd, Ramat Yishai, Israel), placed 5 cm distal to the elbow on the right dorsal forearm.
Time frame: 10 minutes before morphine/placebo administration
Cold (CPT) and heat (HPT) pain thesholds
Thermal cold and heat stimuli will be applied by a contact heat-evoked potential stimulator (PATHWAYS; Medoc Ltd, Ramat Yishai, Israel), placed 5 cm distal to the elbow on the right dorsal forearm.
Time frame: 60 minutes after morphine/placebo administration
Pressure Pain Threshold
Pressure will be applied to the supinator muscle on the left forearm, 15 cm distal to the elbow by a handheld electronic pressure algometer (Somedic AB, Stockholm, Sweden) with a standard probe of 1 cm2.
Time frame: 10 minutes before morphine/placebo administration
Pressure Pain Threshold
Pressure will be applied to the supinator muscle on the left forearm, 15 cm distal to the elbow by a handheld electronic pressure algometer (Somedic AB, Stockholm, Sweden) with a standard probe of 1 cm2.
Time frame: 60 minutes after morphine/placebo administration
This study is completed, as verified in Jul 2020. You cannot join it, but the record below documents what was studied.
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Aalborg University