What is the treatment for a long-acting insulin (Lantus) overdose?

Treatment of Long-Acting Insulin (Lantus) Overdose

The primary treatment for long-acting insulin overdose is continuous intravenous 10% or 20% dextrose infusion with frequent capillary blood glucose monitoring, recognizing that hypoglycemia may persist for 48-96 hours or longer due to the extremely prolonged action of these insulin analogs. 1, 2

Immediate Management

Initial Stabilization

• Administer 50 mL bolus of 50% dextrose (or 0.5-1 g/kg) immediately for symptomatic hypoglycemia or altered mental status 1, 3
• Assess and secure airway if Glasgow Coma Scale is reduced, as patients may require intubation for airway protection 3
• Establish large-bore IV access for continuous glucose infusion 2

Glucose Replacement Protocol

• Start continuous IV infusion of 10% or 20% dextrose immediately after initial bolus 2
• Monitor capillary blood glucose every 15-30 minutes initially, then hourly once stable 2, 4
• Target blood glucose range of 100-180 mg/dL (5.6-10.0 mmol/L) 1
• Be prepared to administer repeated dextrose boluses for breakthrough hypoglycemia despite continuous infusion 3

Alternative Glucose Administration

• For recurrent hypoglycemia despite IV dextrose, administer intramuscular or subcutaneous glucagon (1-2 mg) 1, 3
• Oral glucose can be used for mild episodes in conscious patients with intact gag reflex 1

Duration of Treatment and Monitoring

Expected Time Course

• Long-acting insulin analogs (glargine, detemir, degludec) require glucose infusion for 48-96 hours, significantly exceeding their usual duration of action 5, 2
• Insulin degludec overdose may cause hypoglycemia lasting up to 400 hours due to markedly prolonged half-life (40+ hours vs. 25 hours at therapeutic doses) 6
• The duration of glucose requirements correlates with the dose of insulin taken: approximately 10.5 hours + 0.028 hours per unit of insulin overdosed 4

Critical Monitoring Parameters

• Continue frequent capillary blood glucose monitoring throughout the entire treatment period 2, 4
• Monitor serum potassium levels closely and correct hypokalemia appropriately, as insulin drives potassium intracellularly 1
• Check liver enzymes, as acute hepatic injury can occur with insulin overdose 2
• Monitor arterial or venous pH if severe metabolic derangements are suspected 3

Advanced Interventions

Surgical Excision

• Surgical excision of the insulin injection site can be considered for massive overdoses, even days after injection occurred 2
• This intervention has been used successfully to remove the depot of unabsorbed insulin 2

Corticosteroid Administration

• Consider IV dexamethasone if hypoglycemia persists despite aggressive glucose replacement, as this may help maintain euglycemia 6
• This approach was successful in one case where standard glucose infusion failed 6

Monitoring Serum Insulin Levels

• Serial serum insulin concentration measurements can predict when the effects of overdose will cease 2, 6
• In degludec overdose, insulin levels may remain elevated for over 400 hours 6

Common Pitfalls to Avoid

Premature Discontinuation of Glucose

• Never discontinue glucose infusion prematurely based on conventional insulin duration of action 5, 2
• Patients may become hypoglycemic much later than predicted from standard pharmacokinetic profiles 4
• Sustained carbohydrate intake and observation are necessary because hypoglycemia may recur after apparent clinical recovery 1

Risk Factors for Prolonged Hypoglycemia

• Non-diabetic patients are more likely to present with severe hypoglycemia and develop recurrent episodes compared to insulin-dependent diabetics 4
• Concomitant alcohol or other drug ingestion enhances insulin action and worsens hypoglycemia 3
• Patients with decreased Glasgow Coma Scale 12 hours after overdose have the poorest prognosis, with overall mortality of 2.7% 3

Restarting Diabetes Treatment

• Once overdose effects have receded, restart diabetes treatment with extreme care, especially in type 1 diabetes patients who require insulin to prevent diabetic ketoacidosis 2
• Begin with reduced doses and titrate carefully based on glucose monitoring 2

Disposition and Follow-up

• All patients with long-acting insulin overdose require hospital admission for prolonged monitoring (minimum 48-96 hours) 2
• ICU admission is appropriate for patients with altered mental status, recurrent hypoglycemia, or massive overdoses 3
• Psychiatric evaluation should be arranged for intentional overdoses before discharge 5, 3