Methacholine Challenge Test

A Methacholine test is a 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 symptoms or conditions such as:

• Persistent cough
• Wheezing
• Shortness of breath
• Asthma

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.

What you should know

Please allow 60 minutes for this test.

Do not drink coffee for four hours prior to your test.

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

FAQs

Does the methacoline taste bad?

No. It has almost no taste at all. Higher doses taste slightly sweet.

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.

Will I get a needle?

No, you breathe in the methacholine.

Contact us

Markham Site:  (905) 472-7020

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