What is the maximum dose of glucagon (Glucagon) administered intramuscularly (IM) for the treatment of hypoglycemia?

Maximum Dose of Intramuscular Glucagon for Hypoglycemia

The maximum dose of glucagon administered intramuscularly for hypoglycemia is 1 mg (1000 mcg) for adults and children, regardless of age or weight. 1

Standard Dosing Protocol

The established intramuscular dose for severe hypoglycemia is:

• Adults and children: 0.5-1.0 mg IM 1
• Standard practice uses the full 1 mg dose for maximum efficacy 2, 3
• No weight-based or age-based dose adjustments are required for the standard IM formulation 4

Expected Response and Timing

After administering 1 mg IM glucagon:

• Blood glucose increases within 5-15 minutes of administration 4, 5
• Recovery of consciousness occurs in approximately 6.5 minutes on average 3
• The hyperglycemic effect is more potent and longer-lasting with IM administration compared to IV, particularly in insulin-dependent diabetic patients 2
• Peak glucagon concentrations reach >60-fold higher than baseline with the standard 1 mg IM dose 6

Critical Clinical Considerations

Important caveats about glucagon administration:

• Nausea and vomiting are common side effects, particularly with the 1 mg dose 4, 5, 6
• The airway must be protected before administration in patients with altered mental status due to risk of aspiration from vomiting 4
• IV dextrose is preferred over glucagon in the ICU setting due to faster response time when venous access is available 1
• Blood glucose should be monitored after administration to ensure adequate response 4

When Glucagon May Be Insufficient

If the patient does not respond adequately to the initial 1 mg IM dose:

• Switch to IV dextrose administration (20-40 mL of 50% glucose solution initially, with additional doses if blood glucose remains <3.9 mmol/L) 1
• The slower response with glucagon (achieving final blood glucose of 167 mg/dL after 140 minutes in some cases) makes it less ideal than IV dextrose when venous access is available 1

Alternative Formulations

While the question asks specifically about IM dosing, newer formulations are now preferred:

• Intranasal glucagon (3 mg) and ready-to-inject preparations are now preferred over traditional reconstitution kits due to ease of administration and more rapid correction 4
• These newer formulations do not change the maximum effective dose concept but offer practical advantages in emergency situations 4