A Case Report of Angiotensin II Use in the Treatment of Refractory Shock due to Amlodipine and Lisinopril Toxicity

Introduction: Coingestion of cardiovascular drugs with angiotensin-converting enzyme inhibitors (ACEIs) can be associated with refractory shock derangements complicated by vasopressor resistance, prompting the use of novel, unconventional, or uncommonly used agents. Case Report: A young adult male presented to the emergency department (ED) 10 h after ingesting lisinopril and amlodipine. On arrival, he was hypotensive with a blood pressure of 72/39 mmHg. In addition to crystalloid fluids, he was incrementally started on four vasopressors including norepinephrine, phenylephrine, epinephrine, and vasopressin without improvement in mean arterial pressure (MAP). He was then administered methylene blue, calcium gluconate, and hyperinsulinemic euglycemia therapy after discussion with medical toxicology. Shortly afterwards, he was started on an angiotensin II infusion with an improvement in MAP to a goal of > 65 mmHg. Conclusion: Despite evidence of efficacy in refractory vasodilatory shock secondary to sepsis, there is a paucity of data on the use of angiotensin II as an adjunctive vasopressor in drug-induced shock. We report a case of successful use of angiotensin II in combined lisinopril and amlodipine overdose refractory to conventional vasopressor support. Combined overdose of ACEIs with calcium channel blockers (CCBs) has been shown to cause more significant hypotension and higher vasopressor requirements than overdose of CCBs alone. This may be due to the synergism between CCBs and ACEIs, where the normal homeostatic mechanism of the renin-angiotensin-aldosterone system (RAAS) activation in response to shock is now inhibited, leading to decreased compensatory vasoconstriction via angiotensin II and decreased endogenous catecholamine release. We hypothesize that angiotensin II may have been of particular benefit in this patient given the likelihood that reduced angiotensin II levels were contributing to his refractory shock.