Persistent Hyperinsulinemia Following High-Dose Insulin Therapy: A Case Report

Area of Science:

• Toxicology
• Pharmacology
• Emergency Medicine

Background:

• Overdoses of beta-adrenergic antagonists and calcium channel antagonists are rare but severe clinical events.
• Potential treatments include fluids, calcium salts, vasopressors, intravenous lipid emulsion, methylene blue, and high-dose insulin (HDI).
• The pharmacokinetics of insulin during HDI therapy for these overdoses are not well understood.

Observation:

• A case report details a 51-year-old male with a life-threatening overdose of amlodipine and metoprolol tartrate.
• The patient received HDI therapy augmented with epinephrine for severe bradycardia and hypotension.
• Following discontinuation, serum insulin levels remained supraphysiologic for at least 24 hours and above reference range for days.

Findings:

• Supraphysiologic insulin levels persist for a significant duration after HDI therapy cessation in overdose patients.
• This prolonged presence of insulin may permit straightforward discontinuation of HDI without complex titration.
• Dextrose replacement is necessary, but the duration of need is unpredictable, potentially not requiring prolonged infusions.

Implications:

• Understanding insulin kinetics post-HDI therapy can simplify treatment protocols for severe poisonings.
• This case suggests that HDI discontinuation can be managed without tapering, potentially reducing ICU resource utilization.
• Further research into insulin pharmacokinetics in overdose scenarios is warranted to refine treatment guidelines.