ACE Inhibitors — Adverse Effects & Nursing
The dry, persistent cough your patient blames on allergies might actually be their lisinopril — and ignoring it could mean missing the early warning of a far more dangerous reaction.
Core Concept
ACE inhibitors (lisinopril, enalapril, ramipril) block the breakdown of bradykinin, which accumulates in lung tissue and triggers a dry, nonproductive cough in up to 20% of clients. This cough is not dose-dependent and won't resolve with cough suppressants — the drug must be switched, typically to an ARB. The life-threatening adverse effect is angioedema: swelling of the lips, tongue, and throat that can obstruct the airway. It can occur at any point during therapy, even years after initiation, and requires immediate drug discontinuation and emergency airway management. Hyperkalemia is the key lab concern because reduced aldosterone secretion causes potassium retention. Monitor serum potassium closely, especially if the client also takes potassium-sparing diuretics or potassium supplements. Baseline and periodic monitoring of BUN, creatinine, and potassium is required. First-dose hypotension is common — have the client sit or lie down after the initial dose and monitor blood pressure for 2 hours. ACE inhibitors are absolutely contraindicated in pregnancy (teratogenic, especially second and third trimesters) — teach all clients of childbearing potential to use reliable contraception and report suspected pregnancy immediately.
Watch Out For
Don't confuse the ACE inhibitor cough (dry, persistent, bradykinin-mediated) with a respiratory infection or worsening heart failure (productive cough, crackles, dyspnea). Angioedema from ACE inhibitors can appear months to years into therapy — students assume it only happens with the first dose. Hyperkalemia, not hypokalemia, is the electrolyte risk; this is the opposite of loop diuretics, which are often co-prescribed.
Clinical Pearl
Cough is annoying, angioedema is deadly — both come from the same bradykinin buildup. If the lips start swelling, stop the drug and protect the airway first.
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