What adjustments should be made to a patient's insulin glargine (insulin glargine) regimen, currently 12 units in the morning and 10 units at bedtime, due to decreased oral and fluid intake?

Insulin Glargine Management in Patients with Decreased Oral Intake

Reduce the total daily insulin glargine dose to 0.1-0.15 units/kg/day (approximately 50% reduction), given primarily as basal insulin, and add correctional rapid-acting insulin for glucose levels >180 mg/dL before meals and at bedtime. 1

Immediate Dose Adjustment Algorithm

For your patient currently on 22 units total daily (12 units AM + 10 units PM):

• Reduce the total daily dose by approximately 50% to prevent hypoglycemia in the setting of poor oral intake 1
• Calculate the new dose: If the patient weighs approximately 70 kg, the reduced dose would be 7-10.5 units daily (0.1-0.15 units/kg/day) 1
• Administer the reduced basal insulin as a single daily dose rather than split dosing, as the primary goal is maintaining basal coverage with minimal hypoglycemia risk 1
• Add correctional insulin coverage using rapid-acting insulin analogs for glucose levels >180 mg/dL (10 mmol/L) before meals and at bedtime 1

Critical Rationale for Dose Reduction

The guideline evidence is clear that patients with reduced oral intake require substantially lower insulin doses:

• Most elderly patients and those with acute illness have reduced oral intake due to lack of appetite, medical procedures, or surgical interventions 1
• In such patients, the starting insulin total daily dose should be reduced to 0.1-0.15 units/kg/day, given mainly as basal insulin 1
• This represents a basal-plus-correction insulin regimen, which is the preferred treatment for patients with poor oral intake or those receiving nothing by mouth 1

Hypoglycemia Risk Factors to Monitor

Your patient is at particularly high risk for hypoglycemia due to:

• Reduced oral intake is a major iatrogenic hypoglycemia trigger in hospitalized patients 1
• NPH insulin has a peak of action 8-12 hours after injection, creating risk of hypoglycemia in patients with poor oral intake (though your patient is on glargine, the principle of dose reduction still applies) 1
• Hospital-related hypoglycemia is associated with higher mortality, making prevention critical 1

Monitoring and Adjustment Protocol

• Perform point-of-care glucose testing every 4-6 hours given the unstable clinical situation 1
• If hypoglycemia occurs, immediately reduce the basal insulin dose by 10-20% and determine the underlying cause 1
• Adjust insulin doses daily based on glucose patterns rather than waiting for stable patterns 1
• Target blood glucose of 140-180 mg/dL for most non-critically ill hospitalized patients 1

Common Pitfalls to Avoid

• Do not continue the full home insulin dose in patients with decreased oral intake—this is a recipe for severe hypoglycemia 1
• Do not rely on sliding-scale insulin alone as monotherapy; maintain basal insulin coverage even at reduced doses 1
• Do not stop basal insulin completely even if the patient is NPO; instead, reduce the dose and provide dextrose-containing IV fluids if needed 1
• Avoid using premixed insulin formulations in hospitalized patients due to unacceptably high rates of iatrogenic hypoglycemia 1

Special Considerations for Fluid Intake

• Decreased fluid intake compounds the risk as it may indicate more severe illness or inability to self-report hypoglycemic symptoms 1
• Ensure IV hydration is adequate if oral fluid intake is significantly compromised 1
• Consider whether the patient can reliably report hypoglycemic symptoms—altered ability to report symptoms is a major hypoglycemia trigger 1

When to Advance Therapy

• Once oral intake improves, gradually increase basal insulin by 2-4 units every 3 days based on fasting glucose levels 1
• If the patient remains NPO or on minimal intake for >24-48 hours, consider transitioning to IV insulin infusion with validated protocols if in a critical care setting 1
• Resume home insulin doses only after oral intake has normalized and glucose patterns demonstrate need for higher doses 1