Pulmonary function and airway responsiveness during long-term therapy with captopril

Area of Science:

• Pulmonary Medicine
• Pharmacology

Background:

• Angiotensin-converting enzyme (ACE) inhibitors are frequently prescribed for hypertension.
• Cough is a common side effect of ACE inhibitors, but its underlying mechanism remains unclear.
• The relationship between ACE inhibitor-induced cough and pulmonary function changes requires further investigation.

Purpose of the Study:

• To investigate the effects of captopril on pulmonary function and bronchial responsiveness in hypertensive patients.
• To determine if captopril-induced cough is associated with airflow obstruction or increased airway hyperresponsiveness.

Main Methods:

• A study involving 15 hypertensive subjects treated with captopril.
• Measurements of lung volumes, expiratory flows, and bronchial responsiveness to methacholine were taken before and after eight weeks of treatment.
• Subjects self-recorded respiratory symptoms and peak expiratory flow rates throughout the study.

Main Results:

• Four subjects developed a persistent cough attributed to captopril.
• No significant changes in lung function (lung volumes, expiratory flows) were observed during captopril treatment.
• The mean provocative concentration of methacholine causing a 20% fall in forced expiratory volume in 1 second (FEV1) showed a trend towards a lower value after treatment, but the cough was not associated with airflow obstruction or hyperresponsiveness.

Conclusions:

• Ambulatory treatment with captopril does not significantly alter lung function in hypertensive patients.
• The development of cough associated with captopril use is not linked to the onset of airflow obstruction or bronchial hyperresponsiveness.