[Bronchial reactivity and cough due to ACE inhibitors]

The occurrence of a dry, nonproductive cough during ACE inhibitors therapy has been described in several reports. However, the mechanism of this effect is still unknown. In order to clarify whether ACE inhibitor-induced cough is a symptom of an asthmatic disturbance, six patients (age 54-68) with cough related to captopril or enalapril were rechallenged with ACE inhibitors after an adequate washout period. Baseline airway function and bronchial reactivity to metacholine were measured at the end of the washout period and on the fourth day of rechallenge which was accompanied by the reappearance of cough without wheezing. Rechallenge did not cause changes in dynamic lung function; a low and not significant (p less than 0.1) increase in metacholine dose causing a 15% and a 20% reduction in baseline FEV 1 was observed. It is concluded that cough and bronchoconstriction are likely to be mediated through different nervous pathways and that ACE inhibitor-induced cough is not a variant of asthmatic cough.