Physician Assistant Children's Hospital of Philadelphia Philadelphia, Pennsylvania, United States
Abstract: Introduction Calcium channel blockers are the leading cause of mortality from drug overdose seen in cardiovascular medicine. Amlodipine is a long acting calcium channel blocker in the Dihydropyridine class that binds and blocks L Type calcium channels in the smooth muscle cells of the arterial vasculature, resulting in vasodilation and a decrease in systemic vascular resistance. We report a challenging case of amlodipine and losartan co-ingestion presenting with distributive shock refractory to high-dose conventional vasoactive therapy and institution of extracorporeal membrane oxygenation support, that was successfully rescued with angiotensin-II.
Case Description A 15 year-old male with a past medical history of autism spectrum disorder, depression, and previous suicide attempt, arrived to an outside hospital emergency department following ingestion of 30+ tablets of amlodipine 5 mg, and 10+ tablets of losartan/hydrochlorothiazide of unknown size. He was intubated on arrival for altered mental status and resuscitated with crystalloid as well as infusions of epinephrine, dopamine, and calcium gluconate. His labs were notable for a troponin of 23 with ST depressions in the lateral leads, lactate of 14, and creatinine of 2.3. With signs of evolving multiorgan dysfunction, he was transferred to the Pediatric Intensive Care Unit. Ongoing attempts to improve cardiac output and vasoplegia were inadequate, and his blood pressure continued to be marginal on high doses of epinephrine, norepinephrine, vasopressin, and calcium gluconate. Echo demonstrated normal biventricular function and no pericardial effusion. Due to his high risk of cardiac arrest, he was transferred to the Cardiac Intensive Care Unit for VA-ECMO cannulation, which was instituted via the right neck. At maximal flows, blood pressure improved transiently; however, the patient continued to suffer from progressive vasoplegia. An angiotensin II infusion was obtained from a nearby hospital and started at 10 ng/kg/min to attempt to improve the patient’s systemic vascular resistance. One hour after initiation, mean arterial pressure increased by 20% and other vasoactive infusions were able to be weaned. Over the course of 24 hours, serum lactate decreased by 85% and multiorgan failure improved. The patient was successfully decannulated from VA ECMO after 7 days. His remaining admission was focused on his mental health and was transferred to an outpatient psychiatry facility.
Discussion The management of severe calcium channel blocker overdose is extremely challenging, with high risk of death. In this case, we report a patient with amlodipine and losartan co-ingestion that could not be supported adequately using a combination of high doses of vasoactive medications and mechanical circulatory support. In this refractory case, addition of angiotensin II successfully rescued the patient’s blood pressure, allowing him to be supported through medication clearance and end-organ recovery. This was the first use of angiotensin II at our institution, and provided insight on the utilization of this non-conventional vasopressor.
