Intravenous lipid emulsion in the management of amlodipine overdose

To report a case of amlodipine overdose successfully treated with intravenous lipid emulsion (ILE).

A 47-year-old, 110 kg female ingested at least 350 mg of amlodipine with an unknown amount of ethanol. Initial blood pressure was 103/57 mm Hg, mean arterial pressure (MAP) 72 mm Hg, and heart rate 113 beats per minute. In the early clinical course, activated charcoal, intravenous fluid, and calcium boluses were administered. Worsening hypotension prompted a 100 mL bolus of 20% ILE. Stable hemodynamics were maintained for 2 hours. Subsequently, profound hypotension and shock developed (MAP 38 mm Hg), which failed to fully respond to 3 vasopressor agents, calcium, and glucagon. With continuing shock despite optimized vasopressors, an infusion of 2,300 mL 20% ILE was administered over 4.5 hours (20.9 mL/kg infusion total). By completion of the infusion, 2 vasopressors were tapered off and MAP remained above 70 mm Hg; within 12 hours, no further interventions were required. Possible adverse events of ILE, lipemia and hypoxia, were experienced but quickly resolved. The patient survived to hospital discharge within 8 days.

Toxicity of amlodipine presents similar to distributive shock as both are due to marked peripheral vasodilation. There are numerous interventions in the management of amlodipine overdose, despite which many patients continue to suffer life-threatening shock as observed with this patient. ILE has been used with promising preliminary results as salvage therapy in case reports of other lipophilic molecules. This is the first report of lone amlodipine overdose treated with ILE.

ILE is a novel antidote for overdoses of lipophilic substances and demonstrated efficacy in this case of amlodipine overdose without the use of hyperinsulinemic euglycemia.