Intermediate but not low doses of aspirin can suppress angiotensin-converting enzyme inhibitor-induced cough

This self-matched control study aimed to compare the efficiency of two diff erent regimens of active treatment: aspirin in low (100 mg daily) versus in termediate (500 mg daily) doses in abolishing angiotensin-converting enzyme inhibitor (ACEI)induced cough. A dry bothersome cough is the most common adverse class effect of all angio tensin-converting enzyme inhibitors. Prostaglandins (PG) have been pinpoint ed as playing a leading role in the genesis of ACEI-associated cough. The r ole of different doses of the most commonly used PG inhibitor-aspirin-in AC EI cough modification was not yet elucidated. Of 350 consecutive ACEI-treated patients, we identified 34 (9.7%) nonsmokin g ACEI-related coughers. Patients with lung disease, nonsteroidal anti-infl ammatory drug (NSAID) treatment, and those who did not agree to participate in the study were excluded. In the remaining 14 ACEI coughers (eight men, six women; mean age, 63 +/- 11 years), the treatment was discontinued; the dry cough completely disappeared, but returned in all patients within 1 wee k after ACEI reintroduction. At the end of the rechallenge period, patients started a low dose of aspirin for 1 week, switching thereafter to the inte rmediate dose of aspirin for an additional week. On each visit the cough se verity (CS, 0-4) and frequency (CF, 0-10) scores were registered. Low doses of aspirin were ineffective in suppressing ACEI-induced cough, wh ereas intermediate doses completely abolished cough in five patients and re duced coughing in all but one patient; CS and CF decreased, respectively, f rom 2.5 +/- 1.0 to 0.9 +/- 1.1, P < .002 and from 6.6 +/- 2.4 to 2.4 +/- 1. 1, P <.0002. Overall, intermediate doses of aspirin beneficially modified c ough scores in 13 (93%) patients, enabling nine (64%) to continue ACEI trea tment. Aspirin did not influence blood pressure control either in hypertens ives or in postinfarction patients. We conclude that intermediate but not low doses of aspirin probably can sup press ACEI-induced cough. These findings propose a new alternative therapeu tic approach for patients with ACEI-related cough, especially those in whom ACEI treatment seems to be essential. (C) 2000 American Journal of Hyperte nsion, Ltd.