Pain Thresholds Under High-dose Topical Capsaicin

Pain Clinical Trial

Official title:

Heat-, Cold-, and Mechanical Pain Thresholds Under Exposition of High Dose Topical Capsaicin

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT02570841
• Other study ID #: FA738B0401
• Status: Completed
• Phase: Phase 4
• First received: September 8, 2015
• Last updated: October 5, 2015
• Start date: February 2015
• Est. completion date: September 2015

Study information

• Verified date: October 2015
• Source: Medical University of Vienna
• Contact: n/a
• Is FDA regulated: No
• Health authority: Austria: Agency for Health and Food Safety
• Study type: Interventional

Clinical Trial Summary

Aim of the study is to determine heat pain thresholds (HPT in °C) and cold pain thresholds (CPT in °C) during topical capsaicin 8% application, and mechanical pain thresholds (MPT in g) immediately after to find out the exact skin temperature by which capsaicin initiates the application pain (heat pain threshold, HPT in °C) but also the temperature by which capsaicin does not yet trigger a cold pain (cold pain threshold, CPT in °C). Moreover the investigators want to find out the mechanical pain threshold in g from topical capsaicin and to verify a prolonged effect of capsaicin on the pain thresholds.

Description:

Capsaicin is the main pungent ingredient in chili peppers. Topical capsaicin 8% is used for the treatment of peripheral neuropathic pain. Application of capsaicin 8% provokes distinct pain by activating the transient receptor potential vanilloid 1 (TRPV1) receptor. Cooling the skin results in a reliable prevention of the application pain. However, the necessary cooling temperature and if cooling itself produces application pain, is unknown.

Materials and Methods: 10 female and 10 male healthy volunteers will be enrolled in a randomised, double blind, placebo controlled, cross-over study. The left or right forearm of each subject is going to be treated with a capsaicin 8% patch (QUTENZA, Astellas Pharma, Tokyo, Japan) of 9 cm² or a placebo patch (Demo patch, Astellas Pharma, Tokyo, Japan) of the same size for 60 min. Then the other forearm (which has not been tested before) will be treated with the remaining patch. During capsaicin and placebo exposure HPT in °C and CPT in °C are going to be obtained by the thermode of a thermal sensory analyser, TSA-II (Medoc Ltd., Ramat Yishai, Israel). Temperature increase/decrease of the thermode will be stopped, as soon as the subject presses a switch because of a beginning pain sensation. Immediately after exposure a pin prick test will be performed 5 times in a row by pressing a Mini-Spike (B. Braun Melsungen AG, Melsungen, Germany) slowly against the skin of the application areal to determine the pressure necessary to provoke a sharp pain (Mechanical pain threshold in g). 2 weeks later HPT, CPT, and MPT will be determined again in the areas of capsaicin and placebo exhibition.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 20
• Est. completion date: September 2015
• Est. primary completion date: May 2015
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Both
• Age group: 18 Years and older

Eligibility

Inclusion Criteria:

• healthy volunteers 18 ore more years old

Exclusion Criteria:

• dermatologic or neurologic injuries on both thighs, (possible) pregnancy

Study Design

Allocation: Randomized, Intervention Model: Crossover Assignment, Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor), Primary Purpose: Prevention

Related Conditions & MeSH terms

• Pain

Intervention

Drug:
• Topical High dose Capsaicin
Topical High dose Capsaicin exposure within an area of 3x3 cm for 60 minutes
• Topical Placebo
Placebo exposure within an area of 3x3 cm for 60 minutes

Locations

Country	Name	City	State
Austria	Department of Anesthesia, Critical Care and Pain Medicine	Vienna

Sponsors (2)

Lead Sponsor	Collaborator
Medical University of Vienna	Astellas Pharma GmbH

Country where clinical trial is conducted

Austria, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Heat pain threshold (HPT) in degrees Celsius (°C)	During capsaicin and placebo exposure HPT in degrees Celsius (°C) is determined by a thermal sensory analyser TSA-II (Medoc Ltd.)	60 minutes during topical highdose Capsaicin/Placebo exposure	No
Secondary	Cold pain threshold (CPT) in degrees Celsius (°C)	During capsaicin and placebo exposure CPT in degrees Celsius (°C) is determined by a thermal sensory analyser TSA-II (Medoc Ltd.)	60 minutes during topical highdose Capsaicin/Placebo exposure	No
Secondary	Mechanical pain threshold (MPT) in grams (g)	After capsaicin and placebo exposure MPT in grams (g) is determined by pressing a Mini-Spike (B. Braun Melsungen AG, Melsungen, Germany) slowly against the skin of the application areal to determine the pressure necessary to provoke a sharp pain	Immediately after topical highdose Capsaicin/Placebo exposure	No
Secondary	HPT in degrees Celsius (°C)	HPT in degrees Celsius (°C) will be determined again in the areas of capsaicin and placebo Exhibition	2 weeks after exposure	No
Secondary	CPT in degrees Celsius (°C)	CPT in degrees Celsius (°C) will be determined again in the areas of capsaicin and placebo Exhibition	2 weeks after exposure	No
Secondary	MPT in grams (g)	MPT in grams (g) will be determined again in the areas of capsaicin and placebo Exhibition	2 weeks after exposure	No