Case of the Month #35 Calcium Channel Blocker Overdose

Published 19/01/2023

Hyperinsulinaemic euglycaemia (HIE)

High dose insulin overcomes the metabolic effects of calcium channel blocker toxicity by increasing glucose uptake by myocardial cells as well as increasing myocardial lactate oxidation. This improves myocardial contractility without an associated increase in oxygen demand. Risks include hypoglycaemia and hypokalaemia however.  

Suggested protocol (adapted from 2): 

  1. Bolus of 25g dextrose (50mls of 50% dextrose)  

  1. 1 IU/kg of short acting insulin to saturate insulin receptors 

  1. Titrate short acting insulin infusion 0.5-5 IU/kg/hr 

  1. Dextrose 25 g/hr to maintain euglycaemia 

Replace potassium if <2.5mmol/L and there is a source of potassium loss.