DrugLib.com — Drug Information Portal

Rx drug information, pharmaceutical research, clinical trials, news, and more

The Efficacy of Capsaicin Sensitivity Testing in Patients With Irritable Larynx Syndrome

Information source: St. Michael's Hospital, Toronto
ClinicalTrials.gov processed this data on August 20, 2015
Link to the current ClinicalTrials.gov record.

Condition(s) targeted: Cough; Larynx

Intervention: Capsaicin cough challenge test (Other)

Phase: N/A

Status: Not yet recruiting

Sponsored by: St. Michael's Hospital, Toronto

Official(s) and/or principal investigator(s):
Jennifer Anderson, MD, FRCS(C), Principal Investigator, Affiliation: Chief, Department of Otolaryngology - Head and Neck Surgery


Irritable larynx syndrome (ILS) is a hyperkinetic laryngeal dysfunction that is characterized by a persistent cough, voice changes, or breathing difficulties, which are often triggered by an irritant. Diagnosis of ILS is difficult and typically made via a thorough review of the clinical history and, occasionally, the patient's reaction to an odor-provocation test. Standard treatment for ILS is behavioural therapy with a speech language pathologist (SLP), which provides symptom improvement for most patients. However, currently, there are no objective measures of the upper airway hyper-responsiveness in this condition to assist in diagnosing and monitoring disease severity. Since the cough is irritant-based, it is anticipated that patients with ILS will have a hypersensitivity to the irritant capsaicin. Capsaicin is the active component of chili peppers and is what makes them hot. The capsaicin cough challenge is a well recognized test that involves inhaling different concentrations of capsaicin solutions to determine a cough reflex sensitivity. The purpose of this research study is to confirm that ILS patients have a hypersensitivity to capsaicin compared to healthy volunteers. If a hypersensitivity is observed in ILS patients, the second objective of this study will be to see if behavioural therapy improves the cough reflex sensitivity in this patient population.

Clinical Details

Official title: The Efficacy of Capsaicin Sensitivity Testing in Patients With Irritable Larynx Syndrome

Study design: Observational Model: Case Control, Time Perspective: Prospective

Primary outcome: cough reflex sensitivity

Detailed description: The proposed study has two purposes; the first is to utilize capsaicin cough challenge to demonstrate an increased efferent receptor sensitivity level in ILS subjects as compared to a control group. The second is to determine if there is an objective change in capsaicin cough challenge results after behavioral therapy, and whether it correlates to the subjective improvement. Self-reporting measures include two validated cough quality of life (QoL) questionnaires collected at the same intervals as the capsaicin testing.


Minimum age: 18 Years. Maximum age: N/A. Gender(s): Both.


ILS Participants: Inclusion Criteria:

- Diagnosis of ILS as per the St Michael's voice clinic consultation

- Methacholine test performed

- Negative/borderline result for methacholine test and/or negative/incomplete response

for asthma treatment

- Negative test result for gastroesophageal reflux or negative/incomplete response to

reflux treatment

- Allergy test has been completed with negative result or does not account for all


- Agreed to behavioural therapy in SMH Voice Disorders Clinic

Exclusion Criteria:

- Active smoker

- Active respiratory disease (e. g., COPD, pulmonary fibrosis, lung malignancy.)

- Taking an ACE inhibitor

- Pregnant and/or breastfeeding

- Impaired liver and/or renal function

- Neurological disorder

- Psychiatric condition (outside of depression or anxiety)

Healthy Volunteers: Exclusion Criteria:

- Active smoker

- Active respiratory disease (e. g. COPD, asthma)

- ILS diagnosis

- Chronic cough diagnosis

- Known hypersensitivity to capsaicin

Locations and Contacts

St. Michael's Hospital, Toronto, Ontario M5B 1W8, Canada; Not yet recruiting
William To, MSc, Phone: 416-864-6060, Ext: 6591, Email: tow@smh.ca
Jennifer Anderson, MD, Principal Investigator
Susan Tarlo, MB BS, Principal Investigator
Maria Brake, MD, Sub-Investigator
Additional Information

Starting date: August 2015
Last updated: May 28, 2015

Page last updated: August 20, 2015

-- advertisement -- The American Red Cross
Home | About Us | Contact Us | Site usage policy | Privacy policy

All Rights reserved - Copyright DrugLib.com, 2006-2017