Management of Intentional Insulin Overdose
Immediate Treatment Protocol
Administer continuous intravenous dextrose infusion immediately and maintain for a prolonged duration—often 48-108 hours or longer—as insulin overdose, particularly with long-acting formulations like glargine or detemir, causes severe and extremely prolonged hypoglycemia that far exceeds the typical pharmacokinetic profile of these agents. 1, 2, 3
Initial Resuscitation
Assess consciousness level and obtain immediate capillary blood glucose. Patients may present with profound hypoglycemia (glucose <54 mg/dL or near zero) and altered mental status ranging from confusion to coma. 2, 3, 4
Administer 50 mL of 50% dextrose IV bolus if patient is unconscious or severely hypoglycemic (glucose <54 mg/dL). 1, 4
If patient cannot receive IV access or is in field setting, administer intramuscular or subcutaneous glucagon 1 mg (0.5 mg for children <20 kg). 5
Turn unconscious patients on their side to prevent aspiration if vomiting occurs. 5
Continuous Glucose Management
Start 10% dextrose infusion at 100-200 mL/hour immediately after initial bolus. This rate often requires upward titration based on glucose response. 3, 6, 4
Monitor capillary blood glucose hourly for the first 24-48 hours, then every 2-4 hours as stability improves. Frequent monitoring is essential as hypoglycemia can recur unpredictably despite seemingly adequate dextrose infusion. 1, 3
Anticipate need for supplemental dextrose boluses (25-50 mL of 50% dextrose) when glucose drops below 70 mg/dL despite continuous infusion. Multiple rescue boluses are common in the first 48 hours. 3, 4
Expect prolonged glucose requirements lasting 48-108 hours or more, particularly with long-acting insulin formulations (glargine, detemir, degludec). Case reports document glucose infusion requirements extending 59 hours for glargine and 108 hours for mixed insulin overdoses. 2, 3
Critical Monitoring Parameters
Monitor serum potassium, magnesium, and phosphate levels every 4-6 hours initially. Insulin overdose commonly causes hypokalemia, hypomagnesemia, and hypophosphatemia due to intracellular shifts. 1, 7
Correct hypokalemia appropriately with potassium supplementation. This is a life-threatening complication that must be addressed aggressively. 1
Monitor liver enzymes as elevated transaminases are common in insulin overdose. 7, 4
Assess for peripheral edema and fluid overload from large-volume dextrose infusions. This is a common complication requiring clinical vigilance. 6
Diagnostic Confirmation
Obtain plasma insulin and C-peptide levels to confirm exogenous insulin administration. The insulin-to-C-peptide ratio distinguishes exogenous insulin (high insulin, low C-peptide) from endogenous hypoglycemia. 7
Serial insulin levels can guide duration of therapy. Monitoring daily plasma insulin levels allows prediction of when medical clearance is safe—typically when levels approach normal range (<31 uU/mL). 3
In diabetic patients, suspect intentional overdose when hypoglycemia is unexplained, prolonged, and refractory to standard treatment. 8, 7
Advanced Therapeutic Considerations
Octreotide Use in Non-Diabetic Patients
Consider octreotide (50-100 mcg subcutaneously every 6-8 hours) in non-diabetic patients with refractory hypoglycemia despite high-dose dextrose infusions. Octreotide prevents endogenous insulin release triggered by exogenous dextrose administration, thereby preventing rebound hypoglycemia. 6
Octreotide is particularly useful when large dextrose volumes cause complications like peripheral edema or fluid overload. 6
Do NOT use octreotide routinely in diabetic patients, as the mechanism of rebound hypoglycemia differs. 6
Intensive Care Management
Admit all intentional insulin overdose patients to intensive care unit for continuous monitoring. 3, 4
Maintain two large-bore IV lines—one for continuous dextrose infusion and one for rescue boluses and other medications. 3
Do not discontinue dextrose infusion prematurely. The most critical pitfall is stopping glucose support too early based on apparent clinical recovery, leading to severe recurrent hypoglycemia. 1, 2
Psychiatric and Safety Considerations
Immediately consult psychiatry and implement suicide precautions, as intentional insulin overdose represents serious suicidal intent requiring comprehensive mental health evaluation. 8, 7
Risk Factor Assessment
Screen for depression, anxiety, and eating disorders in all diabetic patients, particularly those with history of insulin omission or manipulation. Depression and disordered eating are significantly more common in people with diabetes. 8
Identify patients at highest risk: those with depression, previous suicide attempts, eating disorders (particularly insulin omission for weight loss), and access to large insulin quantities. 8, 7
Recognize that insulin overdose occurs not only in diabetic patients but also in their relatives and healthcare workers with insulin access. 7
Ongoing Mental Health Management
Refer to mental health providers experienced in cognitive behavioral therapy or interpersonal therapy, with collaborative care involving the diabetes treatment team. 8
Do not discharge patient until psychiatric evaluation is complete and safety plan is established. Transfer to inpatient psychiatric facility is typically required. 3
Address underlying diabetes distress, fear of complications, and maladaptive coping behaviors that may contribute to self-harm with insulin. 8
Common Pitfalls to Avoid
Never assume hypoglycemia will resolve quickly based on standard insulin pharmacokinetics. Massive overdoses, especially of long-acting insulins, produce hypoglycemia lasting far longer than expected—up to 4-5 days. 2, 3
Do not rely solely on continuous infusion without rescue boluses available. Breakthrough hypoglycemia requiring multiple dextrose boluses is the rule, not the exception. 3, 4
Avoid stopping glucose monitoring and infusion when patient appears clinically stable. Hypoglycemia may recur after apparent recovery. 1, 2
Do not overlook electrolyte monitoring. Hypokalemia can be life-threatening and requires aggressive correction. 1, 7
Never discharge without comprehensive psychiatric evaluation and safety planning. The mortality risk and recurrence risk are substantial. 7, 4