(1036) Crisis Averted: Overcoming the Perils of Severe Amlodipine Overdose

Monday, February 24, 2025

10:15am – 11:15am Eastern Time

Location: Connections Central - RST 07

First Author(s)

Amelia Bryan, MD (she/her/hers)

George Washington University Hospital
Arlington, Virginia, United States

Co-Author(s)

KM

Katherine Markin, MD

Resident Physician
George Washington University, United States
DR

David Roeuth, MD

Physician
George Washington University, United States
Ahmad Hassan, MD (he/him/his)

USA
HS

Huma Saleem, MD

Research Coordinator
n/a, United States
DY

David Yamane, MD,

Associate Professor
George Washington University, District of Columbia, United States
KH

Katrina Hawkins, MD

Associate Professor of Anesthesiology and Critical Care Medicine
George Washington University, United States
Danielle Davison, MD

Associate Professor, Director of Intensive Care
George Washington University Medical Center
Washington, District of Columbia, United States
IM

Ivana Milojevic, MD

Assistant Professor of Medicine
George Washington University Hospital, United States

Introduction: Amlodipine is one of the most commonly prescribed antihypertensives with over 70 million prescriptions annually in the US. Overdose can lead to profound refractory vasodilatory shock. We present a case of severe amlodipine overdose successfully managed with multiple hemodynamic supportive measures and medication removal strategies.

Description: 39-year-old man was transferred to our hospital for management of refractory shock after ingesting 90 tablets of amlodipine (5mg), 40 tablets of promethazine (12.5mg) and 30 tablets of cyclobenzaprine (10mg). The patient initially presented with altered mental status and apnea requiring intubation followed by refractory shock despite vasopressor therapy. After consultation with poison control he was treated with IV calcium and high dose insulin infusion.

In our institution, patient continued to be hypotensive despite receiving vasopressin, epinephrine, and angiotensin II infusions. A pretreatment amlodipine level was 980 ng/mL (the peak levels with therapeutic dosing is ~ 20 ng/dL). Methylene blue and hydroxocobalamin were administered in consultation with a toxicologist, but without notable improvement. Plasmapheresis was started to reduce serum amlodipine levels. Extracorporeal membrane oxygenation was considered, but echocardiogram revealed preserved cardiac function and additional mechanical support was thought unlikely to be beneficial. Finally, intravenous lipid emulsion treatment was given in conjunction with plasma exchange and shock started to resolve after two sessions.

Within 3 days, all vasopressors were discontinued but course was complicated by acute oliguric kidney injury requiring renal replacement and acute hypoxemic respiratory failure attributed to aspiration pneumonia. He was extubated on hospital day 7 and had progressive recovery of renal function. He was transferred out of the ICU by hospital day 9, and discharged home on day 17.

Discussion: Amlodipine’s vasodilatory effects can lead to significant mortality in overdose. The expected timeline for improvement after massive amlodipine overdose is predictable and based on the 30-50 hour half-life of the medication. This case illustrates how aggressive care can lead to early hemodynamic recovery in cases of significant amlodipine overdose.