High-dose insulin euglycaemic therapy (HIET): How high is high enough and what are the risks?

Area of Science:

• Cardiology
• Toxicology
• Endocrinology

Background:

• Calcium-channel blockers (CCBs) are common in South Africa and frequently involved in overdose cases.
• Amlodipine overdose can lead to significant morbidity and mortality.

Purpose of the Study:

• To report a case of amlodipine overdose managed with exceptionally high-dose insulin euglycaemic therapy (HIET).
• To evaluate the safety and efficacy of exceeding standard insulin dosing protocols in HIET for CCB toxicity.

Main Methods:

• A teenager with amlodipine overdose received HIET with insulin doses significantly higher than standard protocols.
• Continuous monitoring of glucose, electrolytes, and hemodynamic status was performed.
• Concentrated insulin formulations were used to minimize fluid administration.

Main Results:

• No clinically significant hypoglycemia or hypokalemia occurred despite aggressive insulin dosing.
• The patient showed progressive improvement and was discharged on day 3 with a full recovery.
• Concentrated insulin facilitated higher doses while managing fluid balance.

Conclusions:

• Unconventionally high insulin doses in HIET may be safe and effective in resource-limited settings with experienced staff and close monitoring.
• Further research is needed to establish optimal HIET dosing and discontinuation protocols for severe CCB toxicity.
• High-dose insulin therapy is a potential option when conventional hemodynamic support is insufficient for CCB overdose.