Severe non-cardiogenic pulmonary edema following low-dose amlodipine ingestion: a case report

Amlodipine, a dihydropyridine calcium channel blocker, is widely used for hypertension. While peripheral edema is common, non-cardiogenic pulmonary edema (NCPE) is rare and typically linked to overdose. This case reports severe NCPE at a low therapeutic dose.

A 40-year-old male with newly diagnosed hypertension, treated with amlodipine 5 mg and valsartan 160 mg daily for 4 days, was presented with severe sudden dyspnea, palpitations, and restlessness. Examination revealed bilateral lung crackles, oxygen saturation of 68%, and a respiratory rate of 38 breaths/min. Imaging and a pulmonary capillary wedge pressure of 8 mmHg confirmed NCPE. Amlodipine was discontinued, and hydrochlorothiazide 12.5 mg daily was initiated, leading to rapid improvement. Three months later, symptoms recurred 7 hours after accidental ingestion of two 5 mg amlodipine tablets, resolving upon cessation.

This is the first reported case of severe NCPE associated with low-dose amlodipine, confirmed by low wedge pressure and normal echocardiography. Recurrence after re-exposure suggests a possible association, though causality remains unconfirmed.

This case highlights a potential rare association between low-dose amlodipine and severe NCPE, warranting further investigation. Clinicians should consider amlodipine in unexplained NCPE cases, with early discontinuation to improve outcomes.