What is the management for sulfonylurea (oral hypoglycemic medication) poisoning?

Management of Sulfonylurea Poisoning

The definitive treatment for sulfonylurea poisoning includes immediate glucose administration followed by octreotide to prevent recurrent hypoglycemia. 1

Initial Assessment and Diagnosis

• Suspect sulfonylurea poisoning in any patient presenting with hypoglycemia (blood glucose <70 mg/dL), especially if there is a history of diabetes medication access or drug-drug interactions with medications that inhibit sulfonylurea metabolism (e.g., fluoroquinolones, clarithromycin, sulfamethoxazole-trimethoprim, metronidazole, and fluconazole) 2, 3
• Sulfonylurea poisoning can cause prolonged and severe hypoglycemia that may be refractory to standard glucose administration 1
• Obtain immediate blood glucose measurement in all patients with altered mental status, agitation, or diaphoresis 4

Immediate Management

For Conscious Patients

• Administer 15-20g of oral glucose (preferably glucose tablets) if the patient is conscious and able to swallow 5, 4
• Recheck blood glucose after 15 minutes; if hypoglycemia persists, repeat the treatment with another 15-20g of carbohydrate 5, 4
• Continue this process until blood glucose levels return to normal (>70 mg/dL) 5

For Unconscious Patients or Severe Hypoglycemia

1. Establish IV access and administer IV dextrose bolus:

   • Adults: 50 mL of D50W (25g of dextrose) 6
   • Children: 2-4 mL/kg of D25W or 5-10 mL/kg of D10W 6

2. Follow with continuous IV dextrose infusion:

   • Begin with D10W or D5W and titrate to maintain blood glucose between 5.5-11 mmol/L (100-200 mg/dL) 6

Definitive Treatment

Octreotide Administration

• Octreotide is the first-line specific antidote for sulfonylurea poisoning as it inhibits insulin secretion from pancreatic beta cells 1, 6
• Dosing recommendations:
  • Adults: 50 μg IV or SC initially, followed by 50 μg every 6 hours for at least 24 hours 1
  • Children: 1-1.5 μg/kg IV or SC initially, followed by the same dose every 6 hours 1
• Octreotide significantly increases serum glucose concentrations, decreases dextrose requirements, and reduces recurrent hypoglycemic events compared to IV dextrose alone 1

Alternative Treatment Options

• If octreotide is unavailable, diazoxide (3-8 mg/kg IV every 8 hours) can be considered as it also inhibits insulin secretion 7
• However, octreotide has largely replaced diazoxide due to better efficacy and safety profile 1

Monitoring and Duration of Treatment

• Monitor blood glucose levels frequently (every 1-2 hours initially, then every 4 hours once stable) 6
• Continue treatment until the drug's toxic effects have resolved:
  • For second-generation sulfonylureas (glipizide, glyburide, glimepiride): minimum 24-hour observation period 6
  • For chlorpropamide (first-generation): up to 72 hours due to longer half-life 6
• Observe for at least 12 hours after discontinuation of IV dextrose and octreotide before considering discharge 6

Special Considerations

Pediatric Patients

• All children with intentional ingestions require medical assessment and treatment 6
• For unintentional ingestions of ≤1 tablet in children ≤5 years, home monitoring may be appropriate with proper guidance and frequent glucose checks 8
• Children requiring hospital admission should be observed for at least 12 hours, and should not be discharged at night 6

Drug Interactions

• Be aware of medications that can increase sulfonylurea levels through inhibition of metabolism, including azole antifungals, fluoroquinolones, and trimethoprim-sulfamethoxazole 2, 3
• Consider temporarily decreasing or stopping sulfonylureas when these antimicrobials are prescribed 2

Prevention of Recurrent Episodes

• For patients on sulfonylureas with a history of hypoglycemia, consider switching to a non-hypoglycemic class of diabetes medication 2
• If sulfonylurea therapy must be continued, use glipizide or gliclazide which have lower risk of hypoglycemia compared to glyburide 2
• Educate patients and caregivers about the risk of hypoglycemia, its symptoms, and proper management 4

By following this algorithm, clinicians can effectively manage sulfonylurea poisoning and minimize the risk of severe complications from prolonged hypoglycemia.