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

University of Saskatchewan

Status

Completed

Conditions

Asthma

Treatments

Drug: Methacholine challenge

Study type

Interventional

Funder types

Other

Identifiers

NCT00890539

BMC08-247

Details and patient eligibility

About

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.

Full 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.

Enrollment

15 estimated patients

Sex

All

Ages

18+ years old

Volunteers

No Healthy Volunteers

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.