An interventional study of Capsaicin and Trans-cinnamaldehyde in Pain, Pruritus and Neuropathic Pain, sponsored by Aalborg University. Status unknown at 1 site in Denmark. Open to participants aged 18 Years to 60 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2017-04-27.
Sponsored by Aalborg University · Not applicable, Interventional, and Basic science
The purpose of this study is to investigate the potential desensitising effects of repeated applications of capsaicin, trans-cinnamaldehyde and L-menthol on thermal, mechanical and chemical sensory stimulations.
Capsaicin, the compound responsible for the pungency of chili peppers, can induce desensitization to nociceptive (1) and pruriceptive (2) stimuli when topically applied. The purpose of this study is to determine whether repeated topical applications of trans-cinnamaldehyde and L-menthol result in decreased responses to various nociceptive and non-nociceptive thermal and mechanical stimuli and to compare potential alterations with those caused by repeated topical application of capsaicin. Furthermore, this study investigates the temporal profile of said alterations.
Capsaicin 8% patches, trans-cinnamaldehyde 10%, L-menthol 40% and inert vehicle patches will each be applied to 4 4x4 cm predefined areas on the skin of the volar forearms for 1 hour 4 times on 4 consecutive days. Before each application and the day after the last application, cold detection threshold (CDT), warmth detection threshold (WDT), cold pain threshold (CPT) and heat pain threshold (HPT) will be assessed using a Medoc Pathway (Medoc, Israel) equipped with a 3x3 cm contact thermode. On the last day, mechanical detection threshold (MDT) is assessed using a series of von Frey filaments and mechanical pain threshold (MPT) and mechanical pain sensitivity (MPS) is assessed using a series of standardized pinprick stimulators (Aalborg University).
Furthermore, full-field laser perfusion imaging (FLPI) will be used to assess the degree of neurogenic inflammation in each predefined area before and after each substance application and at the last session.
2,450 studies on the registry are indexed under Pain; 945 are open to participants now.
This study's planned enrollment of 22 is below the median of 70 across 2,101 interventional studies indexed under Pain.
Browse Pain studies →Aalborg University is the lead sponsor of 182 studies on the registry; 38 are open to participants now.
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Exclusion Criteria:
Capsacin (8%) patches applied topically 4 times for 1 hour to a 4x4 cm predefined area on the skin of the volar forearms.
Drug: Capsaicin
Trans-cinnamaldehyde (10%, dissolved in 90% ethanol) applied topically 4 times for 1 hour to a 4x4 cm predefined area on the skin of the volar forearms on a cotton ball placed in a plastic chamber to limit evaporation.
Drug: Trans-cinnamaldehyde
L-menthol (40%, dissolved in 96% ethanol) applied topically 4 times for 1 hour to a 4x4 cm predefined area on the skin of the volar forearms on a cotton ball placed in a plastic chamber to limit evaporation.
Drug: L-Menthol
Inert vehicle patches applied topically 4 times for 1 hour to a 4x4 cm predefined area on the skin of the volar forearms.
Drug: Vehicle patch
4x4 cm patch of 8% topical capsaicin applied to the skin of the volar forearm for 1 hour 4 times on 4 consecutive days
1mL of 10% trans-cinnamaldehyde applied to the skin of the volar forearm for 1 hour 4 times on 4 consecutive days
Drug pages: Levomenthol · Menthol
1mL of 40% L-menthol applied to the skin of the volar forearm for 1 hour 4 times on 4 consecutive days
Inert vehicle patch applied to the skin of the volar forearm for 1 hour 4 times on 4 consecutive days
Cold Pain Threshold (CPT)
The pain threshold for cold stimulation assessed using a Medoc Pathway (Medoc, Israel) equipped with a 3x3 cm thermode. CPT is defined as the temperature at which cold induces pain and is expressed in °C.
Time frame: Assessed at 5 visits on 5 consecutive days
Heat Pain Threshold (HPT)
The pain threshold for heat stimulation
Time frame: Assessed at 5 visits on 5 consecutive days
Neurogenic Inflammation Intensity
The average intensity of the neurogenic inflammation as assessed by full-field laser perfusion imaging (FLPI) (expressed in arbitrary units)
Time frame: Assessed before and after application of substances at 5 visits on 5 consecutive days
Neurogenic Inflammation Area
The area of the neurogenic inflammation as assessed by full-field laser perfusion imaging (FLPI) (expressed in arbitrary units)
Time frame: Assessed before and after application of substances at 5 visits on 5 consecutive days
Pain During Application of Capsaicin
Pain during the 60 minute application of topical capsaicin as rated on a visual analog scale (VAS) (0-10)
Time frame: Assessed every 5 minutes during the 60 minute application of capsaicin at 4 visits on 4 consecutive days
Pain During Application of Trans-cinnamaldehyde
Pain during the 60 minute application of trans-cinnamaldehyde as rated on a visual analog scale (VAS) (0-10)
Time frame: Assessed every 5 minutes during the 60 minute application of trans-cinnamaldehyde at 4 visits on 4 consecutive days
Pain During Application of L-menthol
Pain during the 60 minute application of L-menthol as rated on a visual analog scale (VAS) (0-10)
Time frame: Assessed every 5 minutes during the 60 minute application of L-menthol at 4 visits on 4 consecutive days
Pain During Application of Inert Patch (Control)
Pain during the 60 minute application of the inert patch (control) as rated on a visual analog scale (VAS) (0-10)
Time frame: Assessed every 5 minutes during the 60 minute application of the inert patch (control) at 4 visits on 4 consecutive days
Cold Detection Threshold (CDT)
The detection threshold for cold stimulation assessed using a Medoc Pathway (Medoc, Israel) equipped with a 3x3 cm thermode. CDT is defined as the temperature at which cold can be detected and is expressed in °C.
Time frame: Assessed at 5 visits on 5 consecutive days
Warmth Detection Threshold (WDT)
The detection threshold for warmth stimulation assessed using a Medoc Pathway (Medoc, Israel) equipped with a 3x3 cm thermode. WDT is defined as the temperature at which warmth can be detected and is expressed in °C.
Time frame: Assessed at 5 visits on 5 consecutive days
Mechanical Detection Threshold (MDT)
The detection threshold for mechanical stimulation is defined as the smallest force that can be felt and is assessed using a series of standardized von Frey filaments and using the "method of limits" employing a series of stimulations with ascending and descending force expressed in mN.
Time frame: Assessed at day 5 (final visit)
Mechanical Pain Threshold (MPT)
The pain threshold for mechanical stimulation is defined as the smallest force that induces pain and is assessed using a series of standardized pinprick stimulators (Aalborg University) and using the "method of limits" employing a series of stimulations with ascending and descending forces expressed in mN.
Time frame: Assessed at day 5 (final visit)
Mechanical Pain Sensitivity (MPS)
The sensitivity to mechanically induced pain induced by a series of 7 standardized pinprick stimulators (Aalborg University) as rated on a visual analog scale (VAS) ranging from 0-10 with 0 representing no pain and 10 representing the worst pain imaginable.
Time frame: Assessed at day 5 (final visit)
Vibration Detection Threshold
The detection threshold for vibrational stimulation assessed using a Vibrameter (Somedic, Sweden).
Time frame: Assessed at day 5 (final visit)
Plan to share: No
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Start is estimated for Apr 2017; primary completion for Aug 2017, 4 months later.
Of 1,253 non-industry interventional studies with no phase under Pain, half reached primary completion within 11 months of starting (the median), counting those still running; a quarter within 5 and three quarters within 29. This study's planned 4 months is below that.
Counting every sponsor, half of 1,276 studies reached it within 11 months; a quarter within 5 and three quarters within 30.
How these figures are worked out, and which studies are left out of them.
This study is status unknown, as verified in Apr 2017. You cannot join it, but the record below documents what was studied.
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Studies of the drugs tested here: Capsaicin · Levomenthol · Menthol