Drug-Induced Cough Mechanisms and Management

Introduction to ACE Inhibitor-Induced Cough

Dry cough is a well-established class effect of ACE inhibitors, occurring in 5-35% of patients treated with these agents, and is typically dry, nonproductive, associated with a tickling or scratching sensation in the throat, and often worse at night 1
ACE inhibitor-induced cough can begin within hours of the first dose or be delayed for weeks to months after starting therapy, and the mechanism involves accumulation of bradykinin, substance P, and prostaglandins due to inhibition of their degradation 1

The American Heart Association recommends reviewing all medications for ACE inhibitors, as they are the most likely pharmaceutical cause of chronic dry cough, with symptoms beginning after several months of treatment in many cases 1
If taking an ACE inhibitor, the American College of Cardiology suggests discontinuing it under medical supervision regardless of when the cough started relative to beginning the medication, and switching to an angiotensin receptor blocker (ARB) such as candesartan or losartan is the preferred alternative 1
The European Society of Cardiology notes that cough typically resolves within 1-4 weeks after stopping the ACE inhibitor, though it may take up to 3 months in some patients 1

Laryngopharyngeal reflux (silent reflux) is a frequent cause of chronic cough, especially in older, overweight patients with diabetes, and a 4-week trial of proton pump inhibitor therapy may be considered if reflux is suspected 2
The American Thoracic Society suggests that pulmonary edema from congestive heart failure can occasionally present with cough as the sole symptom 3