What is the management of a patient with intentional insulin overdose, presenting with severe hypoglycemia?

Management of Intentional Insulin Overdose with Severe Hypoglycemia

For a patient presenting with intentional insulin overdose and severe hypoglycemia, immediately administer 10-20 grams of intravenous 50% dextrose, stop any insulin infusion if present, and prepare for prolonged glucose monitoring and repeated dextrose administration over 24-72 hours, as hypoglycemia will likely recur due to the massive insulin depot and delayed absorption kinetics. 1, 2

Immediate Emergency Management

First-Line Treatment Protocol

• Administer 10-20 grams of IV 50% dextrose immediately upon recognition of severe hypoglycemia (blood glucose <70 mg/dL), titrated based on the initial glucose value 1, 3
• Stop any insulin infusion if currently running 1, 4
• If the patient is unconscious or unable to swallow, never attempt oral glucose due to aspiration risk—use IV dextrose or IM glucagon instead 1, 3
• For conscious patients who can safely swallow, 15-20 grams of oral glucose is preferred once they regain consciousness 5, 1

Glucagon Administration

• Administer 1 mg intramuscular glucagon into the upper arm, thigh, or buttocks if IV access is delayed or unavailable 5, 6
• Family members and caregivers can safely administer glucagon—this is not limited to healthcare professionals 1, 6
• For pediatric patients weighing <25 kg or age <6 years, use 0.5 mg glucagon 6
• If no response after 15 minutes, repeat the dose while waiting for emergency assistance 6

Pharmacodynamics and Toxicology Considerations

Expected Clinical Course

• Hypoglycemia will be prolonged and recurrent for 24-72 hours or longer after massive insulin overdose due to delayed subcutaneous absorption from the depot effect 7, 8, 9
• A single 25-gram IV dextrose dose produces blood glucose increases of approximately 162 mg/dL at 5 minutes but drops to 63.5 mg/dL by 15 minutes, with return to baseline by 30 minutes—explaining why repeated dosing is necessary 1
• Long-acting insulin formulations (e.g., glargine, detemir, degludec) create particularly prolonged hypoglycemia lasting days 7, 8
• Even oral insulin ingestion can cause symptomatic hypoglycemia despite poor bioavailability (~1%), requiring hospital admission 10

Metabolic Complications Beyond Hypoglycemia

• Monitor for hypokalemia, hypomagnesemia, and hypophosphatemia, which are common complications of insulin overdose 2, 8
• Elevated liver enzymes frequently occur and should be monitored 7, 8
• Correct hypokalemia appropriately as it can be life-threatening 2

Ongoing Management and Monitoring

Glucose Monitoring Protocol

• Recheck blood glucose every 15 minutes after initial dextrose administration until glucose stabilizes above 70 mg/dL 1, 3, 4
• Once stabilized, continue monitoring every 1-2 hours for at least 24-48 hours, or longer depending on the insulin type and dose 3, 7
• Expect 4 or more symptomatic hypoglycemic episodes in the first 12-24 hours despite continuous dextrose infusions 7

Dextrose Infusion Strategy

• Initiate continuous IV dextrose infusion (typically 10% dextrose) after initial bolus to maintain euglycemia 7, 11
• Repeat 10-20 gram IV dextrose boluses as needed if glucose remains <70 mg/dL despite continuous infusion 1, 3, 4
• Avoid overcorrection that causes iatrogenic hyperglycemia 1
• Target blood glucose >70 mg/dL initially, then maintain 100-180 mg/dL for hospitalized patients 1, 3

Oral Carbohydrate Supplementation

• Once the patient regains consciousness and can safely swallow, immediately provide oral fast-acting carbohydrates (15-20 grams of glucose, regular soft drink, or fruit juice) 1, 6
• Follow with long-acting carbohydrates or a meal to restore liver glycogen and prevent recurrence 5, 1, 6
• Continue oral intake when possible to supplement IV dextrose 7, 8

Special Considerations for Intentional Overdose

Octreotide as Adjunctive Therapy

• Consider octreotide (somatostatin analogue) for refractory hypoglycemia in non-diabetic patients who develop rebound hypoglycemia from endogenous insulin release triggered by exogenous dextrose administration 11
• Octreotide may help prevent dextrose-induced hypoglycemia and reduce the massive dextrose volumes required, thereby avoiding complications like peripheral edema 11
• Initiate octreotide if hypoglycemia persists beyond 12 hours despite aggressive dextrose therapy 11

Diagnostic Confirmation

• Measure insulin and C-peptide levels to distinguish exogenous insulin administration from endogenous secretion—elevated insulin with suppressed C-peptide confirms exogenous insulin 8
• This is particularly important in non-diabetic patients presenting with unexplained hypoglycemia who may have access to insulin 8

Risk Factors for Poor Prognosis

• Mortality is 2.7% overall for insulin overdose, with prognosis poorest in patients admitted with decreased Glasgow Coma Scale 12 hours after overdose 7
• Concurrent alcohol or other drug ingestion enhances insulin action and worsens hypoglycemia 7
• Neurological damage can occur from prolonged severe hypoglycemia 7, 8

Mandatory Follow-Up Actions

Treatment Plan Modification

• Any episode of hypoglycemia <70 mg/dL mandates immediate review and modification of the diabetes management plan if the patient has diabetes 4
• Document all hypoglycemic episodes in the electronic health record and track for quality assessment 5, 4
• Evaluate for root cause and aggregate episodes to address systemic issues 5, 4

Psychiatric Evaluation

• Psychiatric evaluation is of paramount importance for early identification of depression and suicidality in intentional overdose cases 8
• Insulin abuse as a mode of suicide occurs not only among people with diabetes but also among their relatives and medical personnel with access to insulin 8
• Address underlying psychiatric conditions before discharge to prevent repeat attempts 8

Discharge Planning

• Prescribe glucagon for home use and train family members on administration 1, 4
• Educate the patient and caregivers on recognizing early hypoglycemia symptoms 1
• Advise patients to always carry fast-acting glucose sources 1
• Recommend medical identification indicating diabetes and hypoglycemia risk 1

Critical Pitfalls to Avoid

• Never give oral glucose to unconscious patients—this creates aspiration risk and is absolutely contraindicated 1, 3
• Do not underestimate the duration of hypoglycemia—insulin overdose requires prolonged monitoring for 24-72 hours minimum, not just until initial glucose normalizes 7, 8, 9
• Do not rely solely on sliding-scale insulin corrections if the patient has diabetes—this reactive approach is strongly discouraged 5, 3
• Avoid using 5% dextrose solutions alone—higher concentrations (10% or 50%) are needed for adequate glucose delivery 7, 11
• Do not discharge the patient once glucose normalizes—recurrent hypoglycemia is expected and requires hospital admission for observation 7, 8, 10
• Be aware that large volumes of IV dextrose can cause significant peripheral edema and fluid overload 11