Toddler with a Sulfonylurea Ingestion: Disposition and Dextrose Strategy
An 18-month-old boy weighing 13 kg was found playing with his grandmother's open bottle of glipizide 10 mg tablets; six tablets are unaccounted for. He is playful and asymptomatic with a point-of-care glucose of 74 mg/dL 30 minutes after the ingestion, heart rate 118, and normal examination. He ate lunch an hour before the ingestion. The emergency department resident asks whether he can be discharged after a meal and one repeat glucose in 2 hours, and whether activated charcoal is worthwhile.
1. Perform the risk assessment and state your disposition decision.
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Estimated ingestion: 6 × 10 mg = 60 mg in a 13 kg child = 4.6 mg/kg - a large ingestion. Sulfonylureas stimulate pancreatic insulin release independent of glucose; hypoglycemia can be profound, recurrent, and delayed, particularly with extended-release products.
Disposition: admit for at least 24 hours with hourly point-of-care glucose, including overnight. A glucose of 74 mg/dL at 30 minutes is not reassuring - onset is typically 1–2 hours but can be delayed, and the child is still in the honeymoon period of absorption. A single normal value at 2 hours does not exclude later hypoglycemia, and discharge after a meal is unsafe.
Activated charcoal: reasonable if given within 1–2 hours of ingestion in a cooperative child with a protected airway, at 1 g/kg (13 g). It may reduce absorption in a large ingestion, but it does not replace glucose monitoring and is never a reason to shorten observation. Do not force it in a struggling toddler.
Also: confirm the exact product (glipizide vs glipizide XL), notify the poison center, and screen for other co-ingestants in the same bottle or nearby medications.
2. The glucose falls to 44 mg/dL at hour 3. Describe your acute treatment and the dose of any adjunctive antidote.
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Acute treatment: give IV dextrose immediately - D10W 5 mL/kg (65 mL) or D25W 2 mL/kg (26 mL); prefer D10W peripherally or dilute D25W to reduce extravasation injury. Recheck glucose in 15 minutes and repeat until >70–80 mg/dL, then start a continuous dextrose infusion (e.g., D10W at 1.5× maintenance) titrated to keep glucose >80 mg/dL. Oral carbohydrate alone is inadequate in a sulfonylurea overdose because insulin secretion is being driven pharmacologically.
Adjunct: octreotide. Dose 4 mcg/kg (52 mcg; usual maximum 50 mcg) subcutaneously or IV every 6 hours (some protocols use every 8 hours), titrated to effect. Octreotide suppresses insulin release and reduces recurrent hypoglycemia, shortening the duration of dextrose infusion and preventing rebound.
Glucagon may be used for a single rescue when IV access is unavailable (0.5 mg for <20 kg, 1 mg for >20 kg), but its effect is transient and depends on hepatic glycogen - it is not a substitute for dextrose and octreotide, and repeated doses can cause vomiting.
Monitoring: hourly glucose, continuous pulse oximetry if obtunded, and neuro checks. Recurrent or refractory hypoglycemia despite octreotide warrants pediatric ICU care and consideration of a high-dose insulin/dextrose strategy or continuous octreotide infusion.
3. The grandmother also takes metformin 1000 mg, and several of those tablets are missing too. How does that change your assessment and monitoring?
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It adds a second, mechanistically different risk that is not hypoglycemia. Metformin is a biguanide: it decreases hepatic gluconeogenesis and increases insulin sensitivity. In an otherwise healthy euglycemic toddler it rarely causes hypoglycemia, but large ingestions can produce lactic acidosis, vomiting, diarrhea, and, rarely, renal or hepatic injury; the effect is delayed (peak 2–3 hours, sometimes later with extended-release products).
Monitoring plan: continue the hourly glucose checks (the sulfonylurea drives that), and add a venous blood gas, lactate, electrolytes, and renal function at baseline and again at 6–8 hours if any symptoms or if the ingestion is large. Watch for tachypnea, Kussmaul breathing, abdominal pain, or altered mental status.
Treatment: supportive care with IV fluids; activated charcoal if within 1–2 hours. For significant lactic acidosis (pH <7.1–7.2 with lactate >5 mmol/L) and symptoms, sodium bicarbonate may be considered, and hemodialysis is reserved for severe refractory acidosis or renal failure.
Disposition: the 24-hour admission for the sulfonylurea already covers the metformin window, but extend observation and add a follow-up chemistry panel if the metformin dose estimate is large (>2–3 g) or if any symptoms develop. Report both ingestions to the poison center.