High dose insulin for treatment of calcium channel blocker overdose: a case series

Abstract

Background: Calcium channel blocker (CCB) overdose may cause hypotension, shock and death. There has been limited evidence on the efficacy of high dose insulin (HDI) as supportive therapy for calcium channel blocker overdose patients. Therefore, we characterised and studied the survival of patients treated with HDI following a calcium channel blocker overdose. Methods: The Poison Information and Clinical Management System was used to identify patients with CCB overdose. For inclusion, patients must be documented to have CCB overdose and hypotension despite calcium salt infusion. Patients were stratified into two groups - with or without HDI treatment. The primary outcome was all-cause mortality. Results were analysed using SPSS version 23.0. Results: Seventeen patients were included in this study. Fifteen (88.0%) patients were diagnosed with hypertension. Four (23.5%) and five (29.4%) patients had diagnosis of a psychiatric disorder and diabetes mellitus, respectively. Six (35.3%) patients also took an overdose of anti-hypertensive medication. The mortality rates of patients were 38.5% and 0% in patients with or without HDI treatment, respectively (P=0.152). There was no significant difference in the time-to-event relationship with respect to all-cause mortality (P=0.594). Conclusions: CCB overdose can be fatal. HDI did not improve survival in patients with CCB overdose.