Angiotensin converting enzyme inhibitor induced cough: experience in Siriraj Hospital.

With the increasing use of angiotensin converting enzyme inhibitors (ACEI) in the treatment of hypertension, particularly in diabetic patients, and heart failure, an annoying cough has frequently been observed. According to the post marketing surveillance studies, the prevalence of cough associated with ACEI was only 0.1-4 per cent. However, many recent studies have observed a very much higher frequency. To examine the incidence and pattern of cough associated with the usage of ACEI (C-ACEI) in a Thai population, mixed retrospective and prospective studies were performed in hypertensive patients who attended the out-patient department, Siriraj Hospital between December 1999 and August 2000. A thousand cases who had used or have been using ACEI were studied. C-ACEI was present in 179 cases of 760 retrospective studied cases (23.6%) and 75 cases of 240 prospective studied cases (31.3%). Cough was typically described as irritative (93.8% retrospectively and 98.7% prospectively, p = 0.05) and nocturnal in onset (74.9% retrospectively and 80% prospectively, p = 0.12), and usually appeared within the first 4 weeks of treatment (41.3% retrospectively and 46.7% prospectively, p = 0.43). Patients who received a full dosage of ACEI did not have to posses an increasing risk of C-ACEI. There was no difference in the prevalence of C-ACEI among types of ACEI, except cilazapril and quinapril which were found to be higher than enalapril in the retrospective study (p < 0.0001 and p = 0.002, respectively). Types of study were shown to influence the prevalence of C-ACEI. Prospective studies yielded a higher rate of C-ACEI than retrospective ones.