What is the management for hypoglycemia (low blood sugar) in a patient who has intentionally overdosed on insulin?

Management of Hypoglycemia After Intentional Insulin Overdose

Immediately administer intravenous dextrose (10-25 grams or 20-50 mL of 50% dextrose) and prepare for prolonged glucose infusion lasting 24-72 hours or longer, as intentional insulin overdose—particularly with long-acting analogues like glargine—requires extended monitoring and treatment far beyond the typical duration of insulin action. 1, 2

Immediate Treatment Protocol

Initial Resuscitation

• Administer IV dextrose immediately without waiting for laboratory confirmation if severe hypoglycemia is suspected: 20-50 mL of 50% dextrose (10-25 grams) as an initial bolus 1
• For unconscious patients or those unable to swallow, IV glucose is mandatory—oral treatment is contraindicated 3, 4
• Draw blood for glucose measurement before treatment when possible, but do not delay treatment to obtain results 1

Continuous Glucose Management

• Initiate continuous IV dextrose infusion immediately after initial bolus, as single doses are inadequate in overdose situations 1, 2
• The maximum safe infusion rate is 0.5 g/kg/hour to avoid glycosuria, though up to 0.8 g/kg/hour retains 95% of administered dextrose 1
• Plan for prolonged infusion lasting 40-72 hours minimum—case reports document glucose requirements extending up to 59 hours with glargine overdose, significantly exceeding its usual pharmacokinetic profile 2, 5

Critical Monitoring Requirements

Glucose Surveillance

• Implement intensive blood glucose monitoring every 1-2 hours initially, as hypoglycemic episodes can recur unpredictably over extended periods 2, 5, 6
• Continue frequent monitoring even after apparent stabilization, as delayed hypoglycemia is common 2, 7
• Consider continuous glucose monitoring (CGM) if available for real-time alerts 3

Electrolyte Monitoring

• Monitor serum potassium, magnesium, and phosphate levels closely, as insulin overdose commonly causes hypokalemia, hypomagnesemia, and hypophosphatemia through intracellular shifts 8, 5, 7
• Check electrolytes every 4-6 hours initially and replace deficits aggressively 5, 7
• Monitor liver enzymes, as elevations are frequently observed 8

Diagnostic Confirmation

Laboratory Assessment

• Measure insulin and C-peptide levels simultaneously to confirm exogenous insulin administration—elevated insulin with suppressed C-peptide confirms intentional overdose 8
• This ratio distinguishes exogenous insulin from endogenous hypoglycemia causes 8
• Document the specific insulin types involved (rapid-acting vs. long-acting) as this determines duration of treatment 2, 5

Duration of Treatment and Observation

Extended Hospital Stay

• Admit all patients for minimum 24-48 hours observation, with longer stays (up to 72+ hours) required for long-acting insulin analogues like glargine or detemir 2, 5, 7
• The pharmacokinetics of insulin analogues in overdose situations are unpredictable and significantly prolonged beyond their usual duration of action 2
• Do not discontinue glucose infusion prematurely—this is a critical pitfall that leads to recurrent severe hypoglycemia 2, 7

Transition to Oral Intake

• Once the patient is conscious and able to swallow, supplement IV dextrose with liberal oral carbohydrate intake 9, 5, 7
• Continue IV infusion alongside oral intake until glucose stability is demonstrated for at least 12-24 hours 5
• Gradually taper IV dextrose rather than abrupt discontinuation 7

Adjunctive Therapies

Glucagon Considerations

• Glucagon has limited utility in insulin overdose as its efficacy depends on hepatic glycogen stores, which become depleted during prolonged hypoglycemia 9, 7
• May be used as temporizing measure (1 mg IM/SC for adults >25 kg, 0.5 mg for children <25 kg) while establishing IV access 9
• Repeated glucagon doses are generally ineffective and should not replace definitive IV dextrose therapy 7

Octreotide

• Octreotide has demonstrated efficacy in sulfonylurea overdose but is not indicated for insulin overdose 7
• Diazoxide is not recommended 7

Psychiatric and Safety Considerations

Mandatory Psychiatric Evaluation

• All intentional insulin overdoses require psychiatric consultation before discharge, as this represents a serious suicide attempt 8, 5
• Depression and suicidality are paramount concerns requiring immediate mental health intervention 8
• Transfer to psychiatric facility is typically necessary after medical stabilization 5

Prevention of Recurrence

• Implement one-to-one observation during hospitalization to prevent repeat attempts 8
• Secure all insulin and diabetes supplies from the patient 8
• Involve family members in safety planning and medication management 8

Common Pitfalls to Avoid

• Premature discontinuation of glucose infusion based on standard insulin pharmacokinetics—overdose situations require much longer treatment 2
• Failing to monitor electrolytes, particularly potassium, leading to life-threatening arrhythmias 5, 7
• Relying solely on glucagon when IV dextrose is the definitive treatment 7
• Discharging patients before 24-48 hours minimum observation 7
• Missing the psychiatric component and discharging without mental health evaluation 8
• Treating oral insulin ingestion as benign—even oral ingestion can cause significant hypoglycemia with massive doses 6