Analysis of the methacholine response in bronchial asthma.

The airway response to methacholine was measured in 27 asthmatics. Selected indices of airway response were measured at 5-, 10- and 20-minute intervals and at three concentrations of methacholine. The mean change from control was significant at all three concentrations and there were no significant differences between time intervals. High correlations were obtained between all indices of airway response to methacholine challenge.