1246: CALCIUM CHANNEL BLOCKER TOXICITY TREATED WITH METHYLENE BLUE AND LIPID EMULSION: A RARE SURVIVOR

Abstract

Introduction: Calcium channel blocker (CCB) toxicity due to intentional overdose (OD) is associated with high morbidity and mortality. Depending on the CCB subclass, symptoms can include altered mentation, hypotension, and bradycardia. The lack of formally recognized guidelines in the treatment of CCB toxicity can complicate management. Description: A 67-year-old female with history of depression was admitted to the ICU after suicidal ingestion of thirty amlodipine 5 mg tablets for shock refractory to volume resuscitation and vasopressor support. Initial vitals were reported as blood pressure 55/29, pulse 86, respirations 18, pulse oximeter 94% on room air, Glascow coma scale of 13 with stuporous mentation. Despite fluids, initiation of norepinephrine, intravenous (iv) calcium and glucagon, her shock persisted. Toxicology was contacted and recommended high dose iv insulin and dextrose which transiently improved blood pressures, however low mean arterial pressures (MAP) necessitated initiation of vasopressin and epinephrine drips. Methylene blue was started, followed by escalation to iv lipid emulsion (ILE) therapy. With this regimen, distributive shock and mentation improved. With time, vasopressor support was weaned and the patient made a complete recovery from severe CCB toxicity. Discussion: Conventional treatment with iv calcium, glucagon, atropine, cardiac pacing and pressors often fail to improve the hemodynamics associated with intentional CCB OD. Adjunct therapy with insulin may improve cardiac myocyte contractility and methylene blue is postulated to improve distributive shock via inhibition of nitric oxide synthase but current literature lacks case control data. ILE therapy should also be considered early in the treatment course and utilized with the guidance of a toxicologist as ILE is not without risk of complications including but not limited to acute pancreatitis, fat embolism, cardiac arrest, kidney injury, ARDS, seizure, and coagulopathy. Despite its growing utility in the treatment of lipophilic drug toxicity, most studies with CCB OD are case reports and based on animal studies rather than clinical trials. This case demonstrates the potential benefits of adjunct treatment with methylene blue and iv lipid emulsion to improve refractory distributive shock.