Double-blind Trial of Mannitol Cream to Block the Effect of Capsaicin Cream (LipTRP)

Capsaicin is a TRPV1 (transient receptor potential vanilloid 1) agonist, causing pain upon application. The investigators wish to determine whether mannitol blocks the effect of capsaicin application. As both cream bases are identical and mannitol addition is the only difference between the creams, if the mannitol cream is more effective in blocking the effect of capsaicin on the TRPV1 (transient receptor potential vanilloid 1) receptor, the investigators will have established that mannitol down-regulates or blocks the TRPV1 (transient receptor potential vanilloid 1) receptor.

Study Overview

• Status: Completed
• Conditions: Pain
• Intervention / Treatment: Drug: 30% Mannitol in vehicle cream; Drug: vehicle cream

Detailed Description

Capsaicin cream, which stimulates the TRPV1 (transient receptor potential vanilloid 1) receptor, causing a burning sensation, will be applied to both halves of the upper lip until a burning sensation with 8/10 intensity on an NRS (Visual Analog Scale) scale is experienced or five minutes have elapsed. Following this, the capsaicin cream will be wiped off and 30% mannitol in vehicle cream ( isopropyl palmitate, caprylic capric triglyceride, propylene glycol, ceteareth 20, cetearyl alcohol, glyceryl stearate, polyethylene glycol 100 stearate, dimethicone, octyldodecanol, lecithin, ethylhexyl glycerin and phenoxy ethanol) will be applied to one half of the upper lip, and vehicle cream alone will be applied to the other half. Cream assignment will be randomized and neither the subject nor the person applying the cream will know which half upper lip has which cream. Every minute for 10 minutes, the heat sensation felt in each half upper lip will be measured, using a visual scale from 0 to 10. A repeated measures analysis of variance will compare the NRS (Visual Analog Scale) scores from the 30% mannitol cream, to the NRS (Visual Analog Scale)scores from the vehicle cream. Significance will be accepted if P less than .05.

• Study Type: Interventional
• Enrollment (Actual): 25
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Canada
  • British Columbia
    • North Vancouver, British Columbia, Canada, V7M 2K2
      • Dr. Helene Bertrand Inc., 220-1940 Lonsdale Ave.

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 19 years to 80 years (ADULT, OLDER_ADULT)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Age between 19 and 80 years

Exclusion Criteria:

• Diet containing capsaicin (Cayenne pepper, capsicum) (spicy foods), more than once a week.
• Meal containing capsaicin (spicy foods) within 5 days prior to the experiment.
• Any lesion, cracking, cold sore or abrasion on the lips
• Inability to tolerate capsaicin containing "spicy foods"
• Wearing lipstick or lip balm on the upper lip
• Inability to fill out an NRS pain scale
• Use of painkilling medication, within 24 hours of the study.
• Allergy to any of the ingredients of the creams, or to mannitol
• History of contact or allergic dermatitis
• Pregnant or nursing women

Study Plan

How is the study designed?

Design Details

• Primary Purpose: BASIC_SCIENCE
• Allocation: RANDOMIZED
• Interventional Model: PARALLEL
• Masking: TRIPLE

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
ACTIVE_COMPARATOR: Mannitol in vehicle cream; Once the capsaicin has been removed, .2 mL of 30% mannitol in vehicle cream will be applied to one half of the upper lip and kept there for 10 minutes.	Drug: 30% Mannitol in vehicle cream; applied to one half of the upper lip following removal of capsaicin cream.; Other Names: Mannitol; mannitol cream; mannite; manna sugar; C6H8(OH)6
PLACEBO_COMPARATOR: Vehicle Cream; Once the capsaicin has been removed, .2 mL of vehicle cream will be applied to the other half of the upper lip and kept there for 10 minutes.	Drug: vehicle cream; application to the other half of the upper lip following capsaicin cream removal

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
NRS heat score, once per minute	Every minute after capsaicin cream application, subject will indicate NRS (numerical rating scale)heat score. When the score has reached 8/10 or after five minutes, the cream will be removed. The time needed to reach 8/10 heat score and the heat score achieved, or the score at five minutes will be recorded. Following application of the test creams, NRS (Visual Analog Scale) heat scores will be recorded once per minute for each side for 10 minutes.	15 minutes per subject

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Side effects of capsaicin cream on upper lip	The subject will be observed for redness, swelling, or other side effects following the capsaicin cream application. These side effects will be recorded	One hour

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Side effects of test creams	The subjects will be observed for side effects of the mannitol cream or the vehicle cream	one hour

Collaborators and Investigators

• Sponsor: University of British Columbia
• Investigators: Principal Investigator: Helene Bertrand, MD, CM, CCFP, Department of Family Practice, University of British Columbia

Publications and helpful links

General Publications

• Ngom PI, Dubray C, Woda A, Dallel R. A human oral capsaicin pain model to assess topical anesthetic-analgesic drugs. Neurosci Lett. 2001 Dec 28;316(3):149-52. doi: 10.1016/s0304-3940(01)02401-6.
• Boudreau SA, Wang K, Svensson P, Sessle BJ, Arendt-Nielsen L. Vascular and psychophysical effects of topical capsaicin application to orofacial tissues. J Orofac Pain. 2009 Summer;23(3):253-64.
• Bertrand H, Kyriazis M, Reeves KD, Lyftogt J, Rabago D. Topical Mannitol Reduces Capsaicin-Induced Pain: Results of a Pilot-Level, Double-Blind, Randomized Controlled Trial. PM R. 2015 Nov;7(11):1111-1117. doi: 10.1016/j.pmrj.2015.05.002. Epub 2015 May 12.

Study record dates

Study Major Dates

• Study Start: December 1, 2013
• Primary Completion (ACTUAL): January 1, 2014
• Study Completion (ACTUAL): January 1, 2014

Study Registration Dates

• First Submitted: October 10, 2013
• First Submitted That Met QC Criteria: October 15, 2013
• First Posted (ESTIMATE): October 16, 2013

Study Record Updates

• Last Update Posted (ESTIMATE): March 4, 2014
• Last Update Submitted That Met QC Criteria: February 28, 2014
• Last Verified: February 1, 2014

More Information

Terms related to this study

• Keywords: Pain; neuropathic pain; neuropathy; Mannitol; Burning pain; TRPV1 receptor
• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Natriuretic Agents; Diuretics, Osmotic; Diuretics; Mannitol
• Other Study ID Numbers: H13-01551