(997) Beta-Blocker and Calcium Channel Blocker Toxicity in Morbid Obesity Treated With HIET

Introduction: Standard treatments for beta-blocker (BB) and calcium channel blocker (CCB) overdoses include but are not limited to, high-dose insulin euglycemic therapy (HIET). The mechanism of action of HIET is related to the “metabolic hunger” of the heart caused by CCB and BB toxicities. HIET increases glucose uptake into myocardial cells improving myocardial function and increases intracellular calcium concentration, allowing for the improvement of calcium-dependent myocardial cell processes. Herein, we present a case of a morbidly obese patient who ingested toxic doses of CCB and BB.

Description: A 60-year-old male with a medical history of atrial fibrillation and morbid obesity (weight 182kg, BMI 64.3) presented after an intentional overdose of 1200 mg extended-release diltiazem and 450 mg of metoprolol succinate. He was intubated for airway protection and admitted with pressor requirements of norepinephrine (65mcg/min), vasopressin (0.04 units/min), and epinephrine (50mcg/min). He was initiated on HIET, up-titrating as blood glucose levels could tolerate to achieve 10 Units/kg/hr (1,820 units/hr). HIET therapy was continued until pressor requirements subsided to norepinephrine monotherapy ( < 20mcg/min). He received a total of 100,768 units of intravenous insulin over 59 hours. His course was complicated by hypoglycemia in the setting of ileus which was treated with total parenteral nutrition and 35% dextrose infusion. Hypoglycemia persisted despite stopping HIET. C-peptide levels after insulin discontinuation were; at 48 hours (0.15ng/ml), at 72 hours (0.08ng/ml), and at 96 hours (3.17ng/ml). On day 5 after HIET discontinuation, hyperglycemia occurred on 35% dextrose infusion, C-peptide levels were 7.22ng/ml. Hemoglobin A1c resulted at 6.3%. On hospital day 9 the patient was extubated and subsequently downgraded from intensive care.

Discussion: Our case demonstrates successful treatment of concurrent BB and CCB overdose with HIET in a morbidly obese patient requiring intravenous insulin doses unreported in the literature. We suspect our patient required a prolonged course due to his obesity and the lipophilic nature of the ingested compounds. Continued investigation of obesity and its effect on the bioavailability of BBs and CCBs may provide insight into a standard duration protocol for HIET.