Conventional and Unconventional Lifesaving Therapies in an Adolescent With Amlodipine Ingestion

Abstract

Amlodipine, a dihydropyridine calcium channel blocker, is commonly prescribed for the treatment of hypertension. Ingestion of an overdose leads to severe hypotension; if the hypotension is not treated, death may be imminent. Conventional and unconventional interventions were used to treat an adolescent who ingested a life-threatening dose of amlodipine. Severe hypotension resistant to conventional treatment with intralipids and hyperinsulinemia-euglycemia therapy led to the use of plasmapheresis and a pneumatic antishock garment as lifesaving measures. Plasmapheresis has been described in only one other case of severe amlodipine overdose, and the use of a pneumatic antishock garment has never been described in the management of a calcium channel blocker overdose. Because short-term use of a pneumatic antishock garment has associated risks, the critical care nurse's anticipation of side effects and promotion of safe use of the garment were instrumental in the patient's care and outcome. A standard daily dose is 2.5 to 10 mg, and the mean half-life is 30 to 55 hours.1 When inappropriate amounts are accidentally or intentionally ingested, severe hypotension and slow metabolic clearance often lead to fatality.2 The mechanism of action of amlodipine lowers the systemic vascular resistance and reduces the influx of extracellular calcium, resulting in inotropic and chronotropic effects on the myocardium. Amlodipine overdoses have been associated with near-fatal and fatal instances of hypotension and reflex tachycardia, hyperglycemia, metabolic acidosis, and pulmonary edema.3-12 Conventional therapies include calcium replacement, vaso pressors, intralipids, high-dose insulin-euglycemia therapy, and plasmapheresis to maintain end-organ perfusion. [5][6][7]10,11,[13][14][15] Critical care nurses are expected to understand conventional multimodal therapies for patients with amlodipine overdose while providing life-sustaining bedside care. At times, unconventional therapies may be used to maintain life support.

Amlodipine Overdose: Is High Dose Insulin Ready for Prime Time

“…Amlodipine is a dihydropyridine CCB with a primary vasodilatory effect on vascular smooth muscle cells via inhibition of calcium influx through L-gated calcium channels in cardiac and vascular smooth muscle cells [3]. Amlodipine overdose typically manifests as vasodilatory shock associated with reflex sinus tachycardia, metabolic acidosis, hyperglycemia, and pulmonary edema [4]. In contrast, non-dihydropyridine CCB medications such as verapamil and diltiazem have more direct effects on cardiac conduction and AV nodal activity so overdose presents as bradycardia and heart block [3].…”