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Methacholine Challenge: Comparison of Doubling and Quadrupling Methacholine Dose Regimes Using the Tidal Volume Method

This study has been completed.
Information provided by:
University of Saskatchewan Identifier:
First received: March 2, 2009
Last updated: November 23, 2009
Last verified: November 2009
The purpose of this study is to determine the difference (if any) in the result of the methacholine challenge (a test used by physicians in diagnosing asthma) when concentrations of methacholine are quadrupled versus doubled.

Condition Intervention
Drug: Methacholine challenge

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Open Label
Primary Purpose: Diagnostic
Official Title: Methacholine Challenge: Comparison of Doubling and Quadrupling Methacholine Dose Regimes Using the Tidal Volume Method

Further study details as provided by University of Saskatchewan:

Primary Outcome Measures:
  • Methacholine PC20 [ Time Frame: 1 week ]

Secondary Outcome Measures:
  • Subject measure of breathlessness - modified Borg scale [ Time Frame: 1 week ]

Estimated Enrollment: 15
Study Start Date: February 2009
Study Completion Date: March 2009
Primary Completion Date: March 2009 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Quadrupling
methacholine challenge using quadrupling concentrations
Drug: Methacholine challenge
Clinical and research test used in asthma
Active Comparator: doubling
doubling concentrations of methacholine
Drug: Methacholine challenge
Clinical and research test used in asthma

Detailed Description:
The purpose of this study is to confirm that the tidal volume technique of methacholine delivery may be employed in methacholine challenges using a quadrupling dose schedule instead of the standard doubling dose schedule with similar diagnostic efficacy, with no increase in patient adverse events, and with a shorter investigational duration. This has previously been shown to be true using the dosimeter technique of methacholine challenge.

Ages Eligible for Study:   18 Years and older   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • You must be over 18 years of age; and
  • You must have a diagnosis of asthma; and
  • Excluding asthma, you are not aware of any other lung conditions or diseases.

Exclusion Criteria:

  • You have a known hypersensitivity (i.e. an overreaction of your immune system) to methacholine or other parasympathomimetic agents or cholinesterase inhibitors (i.e. agents that act in a similar way via your nervous system — to be discussed with study personnel); or
  • You are a nursing mother or if you are a woman of child bearing potential who is, may be, or intends to become pregnant during testing as the effects of methacholine inhalation in these situations are not known; or
  • Your baseline lung function is poor (ie. your FEV or forced expiratory volume in one second, is less than 65% of your predicted values). This will be performed and explained by study personnel prior to commencing methacholine inhalation testing; or
  • You have had any respiratory infections for the last four weeks; or
  • If you have allergies, and have been exposed to agents that trigger your asthma within the last four weeks; or
  • If you have any significant chronic medical condition.
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Please refer to this study by its identifier: NCT00890539

Canada, Saskatchewan
University of Saskatchewan
Saskatoon, Saskatchewan, Canada, S7N 0W8
Sponsors and Collaborators
University of Saskatchewan
Principal Investigator: Donald W Cockcroft, MD University of Saskatchewan
  More Information

Responsible Party: Dr. Donald Cockcroft, University of Saskatchewan Identifier: NCT00890539     History of Changes
Other Study ID Numbers: BMC08-247
Study First Received: March 2, 2009
Last Updated: November 23, 2009

Additional relevant MeSH terms:
Methacholine Chloride
Autonomic Agents
Peripheral Nervous System Agents
Physiological Effects of Drugs
Bronchoconstrictor Agents
Respiratory System Agents
Muscarinic Agonists
Cholinergic Agonists
Cholinergic Agents
Neurotransmitter Agents
Molecular Mechanisms of Pharmacological Action processed this record on May 25, 2017