Angiotensin Converting Enzyme Inhibitor Cough: A Review of Characteristics, Frequency, Mechanism, and Treatment

Abstract

Objectives: : The purpose of this paper is to provide greater understanding of ACE inhibitor cough and appropriate treatment options. Methods: A Medline search of key terms from 1975-2008 was conducted and all types of published material were included in this review. The articles were evaluated for relevance and appropriateness for inclusion in this review. Subjects considered appropriate included ACE inhibitor cough treatment, mechanism of action, incidence and prevalence, genetics, cough characteristics, onset and resolution of cough, and others. Whenever possible, original studies were obtained but several reviews were also used. Results: ACE inhibitor cough is typically a dry, non-productive, persistent but benign cough reportedly occurring in anywhere from 0.5%-50% of patients receiving ACE inhibitors, though most studies indicate less than 20%. The mechanism is not completely understood but seems to be related to a complicated mechanism involving pathways caused by ACE inhibition and including bradykinin, C fibers, and prostaglandins. Several treatment options have been successful in resolving or relieving cough, including NSAIDs, baclofen, cromolyn and others. Results, however, are inconsistent. Anti-tussive agents, switching to a different ACE inhibitor, or lowering the dose of the current ACE inhibitor do not seem to be effective. Conclusions: In spite of its benign nature, ACE inhibitor cough is usually bothersome enough to discontinue the medication and therefore can not be ignored. Several treatments have appeared effective, all of which carry the risk of drug interactions and additional side effects, and alternative therapy such as angiotensin receptor blockers seem to be reasonable in indicated patients.