Methacholine Challenge Make an Appointment Ask a Question Refer Patient Reviewed by George Zeman BS, RRT, CPFT, Charlie Farris, PhD (August 01, 2013) Bronchial provocation (challenge) testing is the most commonly used and accepted approach for evaluating airway hyperresponsiveness (twitchy airways). A common nonspecific challenge agent used for bronchial provocation is aerosolized methacholine. In this test, the patient inhales an aerosol of one or more concentrations of methacholine. Results of pulmonary function tests (e.g., spirometry and specific conductance) performed before and after the inhalations are used to measure the response.