Pain Thresholds Under High-dose Topical Capsaicin

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

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.

Study Overview

• Status: Completed
• Conditions: Pain
• Intervention / Treatment: Drug: Topical High dose Capsaicin; Drug: Topical Placebo

Detailed 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.

• Study Type: Interventional
• Enrollment (Actual): 20
• Phase: Phase 4

Contacts and Locations

Study Locations

• Austria
  • Vienna, Austria, 1090
    • Department of Anesthesia, Critical Care and Pain Medicine

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• healthy volunteers 18 ore more years old

Exclusion Criteria:

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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Capsaicin; Treatment with Topical High dose Capsaicin	Drug: Topical High dose Capsaicin; Topical High dose Capsaicin exposure within an area of 3x3 cm for 60 minutes; Other Names: Topical Capsaicin 8%; Qutenza® patch
Placebo Comparator: Placebo; Treatment with Topical Placebo	Drug: Topical Placebo; Placebo exposure within an area of 3x3 cm for 60 minutes; Other Names: Demo patch

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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
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
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
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
MPT in grams (g)	MPT in grams (g) will be determined again in the areas of capsaicin and placebo Exhibition	2 weeks after exposure

Collaborators and Investigators

• Sponsor: Medical University of Vienna
• Collaborators: Astellas Pharma GmbH
• Investigators: Principal Investigator: Erich Knolle, MD, Department of Anesthesia, Critical Care and Pain Medicine

Study record dates

Study Major Dates

• Study Start: February 1, 2015
• Primary Completion (Actual): May 1, 2015
• Study Completion (Actual): September 1, 2015

Study Registration Dates

• First Submitted: September 8, 2015
• First Submitted That Met QC Criteria: October 5, 2015
• First Posted (Estimate): October 7, 2015

Study Record Updates

• Last Update Posted (Estimate): October 7, 2015
• Last Update Submitted That Met QC Criteria: October 5, 2015
• Last Verified: October 1, 2015

More Information

Terms related to this study

• Keywords: Heat pain threshold; Cold pain threshold; Mechanical pain threshold; High dose Capsaicin
• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Peripheral Nervous System Agents; Sensory System Agents; Dermatologic Agents; Antipruritics; Capsaicin
• Other Study ID Numbers: FA738B0401