Toxicology – Antidote: Hyperinsulinemic Euglycemia (HIE) Therapy

Indications

Hyperinsulinemic euglycemia therapy is used for severe calcium channel blocker (CCB) and beta-blocker poisoning, especially when there is significant myocardial depression, hypotension, or shock.

Mechanism of Action

In severe CCB and beta-blocker toxicity, the heart becomes less able to use its usual fatty-acid energy pathway and relies more heavily on glucose.

High-dose insulin helps by:

• Increasing myocardial glucose uptake
• Improving cellular energy production
• Producing a positive inotropic effect
• Improving cardiac contractility and circulation

In calcium channel blocker overdose, pancreatic insulin release may also be suppressed, producing hyperglycemia with relative hypoinsulinemia.

Administration

HIE therapy uses high-dose IV insulin together with glucose supplementation as needed to maintain normal blood glucose.

Treatment typically involves:

• An initial IV insulin dose
• A continuous high-dose insulin infusion
• Dextrose supplementation when necessary
• Gradual adjustment based on blood pressure, cardiac function, and metabolic response

Because this therapy uses insulin doses far above those used routinely for diabetes, it should be managed in a closely monitored critical-care setting.

Monitoring

Frequent laboratory and bedside monitoring is essential, especially:

• Blood glucose
• Potassium
• Other electrolytes
• Blood pressure
• Heart rate and rhythm
• Cardiac perfusion and overall hemodynamic response

Major Risks

The most important complications are:

• Hypoglycemia
• Hypokalemia

Both require active monitoring and correction during therapy.

Key Points

• HIE is an important treatment for severe CCB and beta-blocker toxicity.
• Its main benefit is improved myocardial energy utilization and contractility.
• CCB poisoning often causes hyperglycemia because calcium-channel blockade reduces pancreatic insulin secretion.
• A useful memory aid is that the poisoned myocardium is energy-starved and benefits from increased glucose utilization.
• HIE should be performed with intensive glucose, electrolyte, and cardiovascular monitoring.