When is it appropriate to stop a D10% (10% dextrose) maintenance IV infusion in a patient with insulin glargine‑induced hypoglycemia after a 50 mL 40% dextrose bolus, given a current glucose of approximately 70 mg/dL?

When to Stop D10% Maintenance Infusion After Insulin Glargine Overdose

Stop the D10% infusion when the patient maintains a blood glucose ≥100 mg/dL for at least 12–24 consecutive hours without any dextrose supplementation, and no further hypoglycemic episodes occur.

Understanding Insulin Glargine Overdose Pharmacokinetics

• Insulin glargine creates a subcutaneous depot that releases insulin slowly over an extended period, causing prolonged hypoglycemia lasting 96–120 hours (4–5 days) after massive overdoses 1, 2.
• A 50 mL bolus of 40% dextrose provides only transient correction; the underlying insulin effect persists for days, necessitating continuous dextrose infusion 1, 2.
• The current glucose of ~70 mg/dL after a single dextrose bolus indicates ongoing insulin activity requiring sustained dextrose support 1, 2.

Immediate Management Protocol

Continue D10% Infusion

• Maintain D10% at 40–100 mL/hour to keep blood glucose consistently ≥100 mg/dL (target range 100–150 mg/dL) 1, 2.
• D10% is preferred over repeated D50 boluses because it provides steady glucose delivery, avoids rebound hyperglycemia, and reduces the risk of extravasation injury from hypertonic dextrose 3, 4.

Monitoring Requirements

• Check capillary blood glucose every 30–60 minutes during the first 24 hours, then every 1–2 hours once stable 1, 2.
• Monitor serum potassium every 2–4 hours because insulin drives potassium intracellularly, risking life-threatening hypokalemia 5.
• Measure serum electrolytes, BUN, creatinine every 4–6 hours to detect metabolic derangements 5.

Criteria for Discontinuing D10% Infusion

Primary Criterion

• Blood glucose remains ≥100 mg/dL for 12–24 consecutive hours after stopping the D10% infusion 1, 2.
• This observation period confirms that endogenous glucose production can sustain normoglycemia without exogenous dextrose 1, 2.

Stepwise Weaning Protocol

1. Reduce D10% infusion rate by 25–50% (e.g., from 100 mL/hr to 50 mL/hr) while monitoring glucose every 1–2 hours 1, 2.
2. If glucose remains ≥100 mg/dL for 4–6 hours, reduce the rate by another 25–50% 1, 2.
3. Discontinue the infusion entirely only when glucose stays ≥100 mg/dL at the lowest infusion rate for 6–12 hours 1, 2.
4. After stopping, continue hourly glucose checks for 12–24 hours to detect delayed hypoglycemia 1, 2.

Safety Thresholds

• Do not stop D10% if glucose falls below 100 mg/dL at any point during weaning; resume the previous infusion rate immediately 1, 2.
• Never discontinue abruptly; the depot effect of glargine can cause recurrent hypoglycemia hours after apparent stabilization 1, 2.

Expected Timeline for Insulin Glargine Overdose

• Days 1–2: Continuous D10% infusion required; glucose typically unstable despite aggressive dextrose 1, 2.
• Days 3–4: Glucose may begin to stabilize; attempt gradual weaning of D10% 1, 2.
• Days 4–5: Most patients can discontinue D10% if glucose remains ≥100 mg/dL without support 1, 2.
• Beyond Day 5: Rare cases require dextrose beyond 120 hours; consider octreotide if hypoglycemia persists 1.

Adjunctive Therapy: Octreotide

• If hypoglycemia persists beyond 96 hours despite maximal D10% infusion (≥100 mL/hr), consider octreotide 50–100 mcg subcutaneously every 8 hours 1.
• Octreotide suppresses endogenous insulin secretion triggered by the dextrose infusion, potentially reducing dextrose requirements 1.
• This is an off-label use supported by case reports, not randomized trials 1.

Nutritional Support

• Encourage liberal oral carbohydrate intake (complex carbohydrates preferred) in addition to D10% infusion to reduce total IV dextrose volume 2.
• Oral intake alone is insufficient in the acute phase; IV dextrose remains mandatory 2.

Common Pitfalls to Avoid

• Do not rely on a single normal glucose reading to stop D10%; the depot effect causes unpredictable recurrent hypoglycemia 1, 2.
• Do not use D50 boluses alone; they cause rebound hyperglycemia followed by recurrent hypoglycemia without addressing the underlying prolonged insulin effect 3, 4.
• Do not discharge the patient until glucose remains ≥100 mg/dL for 24 hours off all dextrose; premature discharge risks life-threatening hypoglycemia at home 1, 2.
• Do not stop monitoring after 48 hours; hypoglycemia can persist for 96–120 hours post-overdose 1, 2.

Disposition and Follow-Up

• ICU admission is mandatory for all insulin glargine overdoses requiring continuous dextrose infusion 1, 2.
• Psychiatric evaluation is required before discharge for intentional overdoses 2.
• Discharge only after 24 hours of stable glucose ≥100 mg/dL without dextrose and psychiatric clearance 2.