Effect of inhaled amiloride on the bronchial response to methacholine and cold air hyperventilation challenges.

Inhaled amiloride has been recently demonstrated to have an effect on the decline of pulmonary function in patients with cystic fibrosis. Other diuretics have been demonstrated to provide protection against bronchoconstriction in asthmatic subjects. We report on the effect of inhaled amiloride on cold air hyperventilation challenge (CAHC) and methacholine challenge in asthmatics.

Probability of asthma based on methacholine challenge.

Methacholine inhalation challenge has become an accepted test to determine the presence of airway hyperresponsiveness, a hallmark of asthma. To help physicians interpret the results of a methacholine challenge test in a clinical setting, we analyzed the test data of 1,105 subjects, asthmatics and nonasthmatics. Applying Bayes' theorem, a nomogram was constructed incorporating the prechallenge clinical diagnosis with the response to methacholine to give a posttest probability of the diagnosis of asthma.