Methacholine Challenge Test

The methacholine challenge is a safe breathing test that is helpful in determining the extent airway reactivity.

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

You will be asked to inhale a varying amount of an agent called methacholine.

Frequently asked questions about Methacholine

Does the Methacholine taste bad?

No. Patients have commented in the past that the taste reminds them of the Chloraseptic throat spray.

Can I eat or drink before the test?

Yes, you may eat a light meal 2 hours before your test.

Will the methacholine make me cough or feel short of breath?

his is a completely safe test. However, some patients may experience a subtle cough or experience mild shortness of breath. Once the testing ends, you will receive nebulized albuterol to quickly reverse the effect of the Methacholine.

Are there needles involved?

No. The Methacholine is not injected, it is inhaled.

Medications to Withhold

Strict adherence to withholding certain medications is an important part of this test.

Rescue Inhalers - 24 hours prior to test

Albuterol (Proair, Ventolin, Proventil)
Levalbuterol (Xopenex)
Ipratropium (Atrovent)
Epinephrine (Primatene mist)
Combivent, Duoneb 

Leukotriene inhibitors - 48 hours prior to test

Montelukast (Singulair)
Zafirlukast (Accolate)

Long-acting Bronchodilators - 48 hours prior to test

Salmeterol (Serevent)
Formoterol (Foradil, Performist)
Arformoterol (Brovana)

Theophyline - 48 hours prior to test


Antihistamines/Decongestants - 72 hours prior to test

Cetirizine (Zyrtec)
Fexofenadine (Allegra)
Loratadine (Claritin)
Hydroxyzine (Atarax, Vistaril)
Chlorpheniramine/ Pseudoephedrine (and other decongestants)
Diphenhydramine (Benadryl like meds)

Long-acting Inhalers - 1 week prior to test

Tiotropium (Spiriva)
Azelastine (astelin)
Umeclidinium and vilanterol (Anoro Ellipta)
Umeclidinium (Incruse)
Aclidinium bromide (Turdoza)
Glycopyrronium (Seebri)

Inhaled Corticosteroids - 2 weeks prior to test

Breo Ellipta
Beclomethasone (Qvar and Beconase)
Fluticasone (Flonase, Veramyst, Flovent)
Mometasone (Nasonex, Asmanex)
Budesonide (Pulmicort, Rhinocort)
Triamcinolone (Azmacort, Nasocort)
Flunisolide (Aerobid, Nasarel)
Ciclesonide (Alvesco)

Oral Glucocorticoids

Methylprednisolone (Medrol)

Please inform us prior to your testing day so we can provide you with more specific instructions.

Caffeine - 24 hours prior to test.

Coffee and tea (decaffeinated and caffeinated)
Any supplements or medicine that may contain caffeine