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Methacholine Test

A methacholine test is a completely safe breathing test that is used to determine the extent of airway reactivity. It is only ordered after a routine pulmonary function test has been completed.

This test is ordered for patients who have normal pulmonary function tests, yet have the following symptoms or conditions:

  •     Persistent cough
  •     Wheezing
  •     Shortness of breath
  •     Asthma

Click here to view the methacholine test brochure.

Location and Contact Information

To make a methacholine test appointment, please visit the Make an Appointment page.

Markham Site

We suggest parking in the main hospital parking lot, opposite the Link Lobby Entrance and Medical Office Building, when visiting diagnostic services.

Please go to the central registration desk on the main floor of Building A, before heading to diagnostic services on the second floor in Building B where you'll be directed to the designated waiting room.

For more information on parking, please click here.

Care Providers

The methacholine test will be performed by a respiratory therapist.

What You Should Know

Your physician will give you detailed instructions and tell you what asthma medications to stop taking prior to the test. Antihistamines and inhalers interfere with the test results. Antihistamines and cold medications must be discontinued four days before a methacholine test. Certain long-acting inhalers such as Advair, Symbicort or Spiriva, must be stopped 48 hours before the methacholine test. Certain short-acting inhalers such as Ventolin or Bricanyl, must be stopped eight hours before the test. Please view the patient instructions for further details.

Click here to view additional patient instructions for a methacholine test.

Before Your Visit

Please review your instruction sheet that has been given to you  prior to the test.

Please arrive 30 minutes before your test to register at the central registration desk in Building A. Please bring your health card and your requisition (if your physician has provided you with one).

During Your Visit

Please allow approximately one hour for this test.

The respiratory therapist performing your exam will ask you to breathe in several doses of a methacholine solution. After each dose, we will test your breathing to see if there is any change.

After Your Visit

There are no specific instructions for after the test You are free to resume your normal routine and resume using  your inhalers as prescribed.

Frequently Asked Questions

Does the methacoline taste bad? No. It has almost no taste at all. Higher doses taste slightly sweet.
What is the minimum age required to perform this test? Patients must be at least eight years of age to have this test.
Can I eat or drink before the test? Yes, you may eat normal meals.
Will the methacholine make me cough? It sometimes causes a cough but you will be given a few puffs of Ventolin to reverse the effect of the Methacholine.
Will I have an asthma attack? No. This is a completely safe test. A slight cough may occur but the therapist will give you an inhaler which will quickly reverse any coughing effects of the methacholine.
Will I get a needle? No. The therapist will use a needle to measure the solution only. Methacholine is not injected. It is inhaled.

Additional Resources

The Canadian Thoracic Society – lung.ca

The American Thoracic Society – thoracic.org/