Final answer:
The classic antidote to beta blocker toxicity is glucagon.
Step-by-step explanation:
The classic antidote to beta blocker toxicity, in addition to high-dose insulin, is glucagon.
Glucagon is a hormone that stimulates mechanisms to increase blood glucose levels, such as the catabolism of glycogen into glucose. It counteracts the effects of beta blockers by increasing heart rate and blood pressure, which can be suppressed by beta blockers.
In cases of beta blocker toxicity, glucagon is administered to reverse the cardiovascular effects and improve outcomes.