ACE Inhibitor-Induced Cough

Characteristics of ACE Inhibitor-Induced Cough

ACE inhibitor-induced cough is a well-documented class effect that occurs in approximately 5-35% of patients taking these medications 1, 2
The cough is typically dry and is associated with a tickling or scratching sensation in the throat 2
The cough is not dose-dependent and can occur regardless of the dose being administered 1, 2

Women are more likely to experience ACE inhibitor-induced cough than men 3
Nonsmokers have a higher incidence of cough compared to smokers 3
Persons of Chinese origin have increased susceptibility 3
Patients treated for congestive heart failure cough more frequently than those treated for hypertension 3

The cough is believed to be caused by the accumulation of bradykinin and substance P in the upper airway or lung when ACE is inhibited 4
These substances are normally degraded by ACE, and their accumulation may lead to sensitization of airway sensory nerves 3, 4
Prostaglandins, which may be stimulated by bradykinin, may also play a role in the development of cough 4

Cough may occur within hours of the first dose or be delayed for weeks to months after starting therapy 3
The cough typically resolves within 1-4 weeks after discontinuation of the ACE inhibitor 1, 3
In some patients, cough may persist for up to 3 months after stopping the medication 3, 4

If a patient on perindopril presents with cough, the medication should be considered as a potential cause regardless of when the cough started relative to medication initiation 1, 2
The diagnosis is confirmed by resolution of cough after discontinuation of the ACE inhibitor 1, 4
It's essential to rule out other causes of cough, especially if the cough is productive rather than dry 5

The only uniformly effective treatment for ACE inhibitor-induced cough is discontinuation of the medication 4
Switching to an angiotensin receptor blocker (ARB) is recommended, as ARBs do not cause cough 4
Some pharmacologic agents have shown limited ability to attenuate ACE inhibitor-induced cough in small studies, including inhaled sodium cromoglycate, theophylline, and certain calcium-channel antagonists 4
In approximately 30% of patients who have experienced ACE inhibitor-induced cough, the cough may not recur if rechallenged with the same medication after a period of discontinuation 4

If a patient presents with productive cough while on perindopril, other causes should be investigated, as ACE inhibitor-induced cough is typically dry 1, 2
Treatment with ACE inhibitors may sensitize the cough reflex, potentially exacerbating cough from other causes 3