Fenobam on Heat/Capsaicin Induced Hyperalgesia in Healthy Volunteers

A Double Blind, Randomized, Placebo Controlled, Crossover Study to Investigate the Anti-hyperalgesic Efficacy of a Single Dose of Fenobam on Heat/Capsaicin Induced Cutaneous Hyperalgesia in Adult Healthy Volunteers.

Our goal is to demonstrate that healthy volunteers treated with fenobam will develop a significantly reduced area of cutaneous hyperalgesia compared to volunteers treated with placebo, after exposure to the heat/capsaicin model of cutaneous sensitization. Additionally we are going to assess changes in mood/affect and cognitive function of subjects following administration of fenobam and after cutaneous sensitization compared to baseline.

Study Overview

• Status: Completed
• Conditions: Hyperalgesia; Allodynia
• Intervention / Treatment: Drug: Fenobam; Drug: Placebo

Detailed Description

All subjects will receive a topical dose of capsaicin cream 0.1%(Capzasin-HP) to the forearm at the start of the study visit. The order of the 2 treatment regimens indicated below will be randomized and blinded to subjects and researchers.

Treatment Regimen 1: Fenobam [1-(3-chlorophenyl)-3-(1-methyl-4-oxo-2-imidazolidinylidine) urea hydrate]: administration of one 150 mg gelatin capsule.

Treatment Regimen 2: Placebo (lactose monohydrate): administration of one 150 mg gelatin capsule.

• Study Type: Interventional
• Enrollment (Actual): 33
• Phase: Phase 1

Contacts and Locations

Study Locations

• United States
  • Missouri
    • St. Louis, Missouri, United States, 63110
      • Washington University School of Medicine

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 50 years (Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

Inclusion Criteria:

1. 18-50 year old
2. Good general health with no remarkable medical conditions (e.g. liver, kidney, heart, or lung failure)
3. BMI between 20-33
4. Willing to comply with study guidelines as outlined in protocol [including: women of childbearing age must be willing to use a double-barrier method (e.g. oral contraception and condom) for contraception during participation in the study]
5. Willing to provide informed consent

Exclusion Criteria:

1. Anatomical malformation of upper extremities
2. Status post recent trauma or chronic lesions on either forearm
3. Medication use (includes vitamin, herbal, dietary and mineral supplements and grapefruit products during or within 14 days prior to study participation; excludes contraceptives)
4. History of allergy or intolerance to capsaicin
5. History of multiple drug allergies
6. History of addiction to drugs or alcohol (prior or present addiction or treatment for addiction)
7. History of chronic pain syndromes
8. Pregnant and nursing females
9. Smokers

Study Plan

How is the study designed?

Design Details

• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Treatment regimn 1; 150 mg Fenobam Orally - once	Drug: Fenobam; Fenobam 150 mg will be administered and subjects will be monitored for up to 8 hours. During the study day questionnaires will be administered, blood will be drawn a testing site will be marked and pain testing and heat/capsaicin sensitization will be measured.; Other Names: [1-(3-chlorophenyl)-3-(1-methyl-4-oxo-2-imidazolidinylidine) urea hydrate]
Placebo Comparator: Treatment Regimen 2; Placebo orally - once	Drug: Placebo; A placebo will be administered and subjects will be monitored for up to 8 hours. During the study day questionnaires will be administered, blood will be drawn a testing site will be marked and pain testing and heat/capsaicin sensitization will be measured.; Other Names: Lactose monohydrate

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Suppression of the development of cutaneous hyperalgesia and allodynia around the area treated with heat/capsaicin.	size of the area of hyperalgesia and allodynia around the area sensitized by heat/capsaicin as quantified by cutaneous stimulation with foam brush strokes and a von Frey filament requiring 26 g of bending force.	During approximately 7 hours of consecutive assessments

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Evaluation of nociception after drug administration as evaluated by prolonged (1 min) thermal stimulation on normal (untreated) skin.	Visual Analog Scale (VAS) rating of pain perception at 1 min 45°C heat stimulation on normal skin.	During approximately 7 hours of consecutive assessments
Assessment of Heat Pain Detection Thresholds (HPDT) in normal and sensitized skin pre and post treatment with fenobam.	lowest temperature perceived as painful with stimulation starting at 32°C and with a safety cut-off at 52°C.	During approximately 7 hours of consecutive assessments
Absence of significant side effects	Determined by subjects' monitoring during treatment sessions and follow up at 1 day and 1 week after treatment with drug.	7 days
Assessment of significant change in mood/affect	As determined by evaluation of the subjects by combined brief Positive And Negative Affect Scale/Brief State Anxiety Measure (PANAS/BSAM)	During approximately 6 hours of consecutive assessments
Assessment of significant change in cognitive function	As determined by evaluation of the Letter and Number Sequencing (LNS) assessment	During approximately 6 hours of consecutive assessments

Collaborators and Investigators

• Sponsor: Laura Cavallone
• Investigators: Principal Investigator: Laura F Cavallone, M.D., Washington University School of Medicine

Study record dates

Study Major Dates

• Study Start: January 1, 2014
• Primary Completion (Actual): February 1, 2015
• Study Completion (Actual): April 1, 2016

Study Registration Dates

• First Submitted: November 4, 2013
• First Submitted That Met QC Criteria: November 4, 2013
• First Posted (Estimate): November 11, 2013

Study Record Updates

• Last Update Posted (Estimate): April 29, 2016
• Last Update Submitted That Met QC Criteria: April 27, 2016
• Last Verified: April 1, 2016

More Information

Terms related to this study

• Keywords: cognitive function; heat; mood; hyperalgesia; allodynia; capsaicin; fenobam
• Additional Relevant MeSH Terms: Nervous System Diseases; Neurologic Manifestations; Sensation Disorders; Somatosensory Disorders; Hyperalgesia
• Other Study ID Numbers: 201311094