Approved methodology for methacholine challenge

The challenge procedure detailed in this article should serve as a useful adjunct to routine pulmonary function testing for the diagnosis of asthma as well as a research tool for a wide variety of applications. Now that methacholine has been approved by the Food and Drug Administration and made available to the clinician in an appropriate form for clinical use (Provocholine, Roche), it is anticipated that the technique of methacholine challenge will become part of the armamentarium of pulmonary laboratories as well as pulmonologists and allergists who diagnose and treat asthma. The technique may be safely conducted in an outpatient setting using the standardized procedures detailed here. When properly applied in appropriate clinical circumstances, the test is a useful and sometimes necessary addition to routine history, physical examination, and pulmonary function tests conducted for the purposes of establishing the presence of hyperactive airways.