How soon after administering Lantus (insulin glargine) can the insulin drip be discontinued?

Timing of Insulin Drip Discontinuation After Lantus Administration

Administer subcutaneous Lantus (insulin glargine) 2 hours before discontinuing the intravenous insulin infusion to prevent rebound hyperglycemia. 1

Optimal Transition Protocol

Timing and Administration

• Give Lantus 2 hours prior to stopping the IV insulin drip when transitioning from intravenous to subcutaneous insulin therapy 1
• This 2-hour overlap allows the long-acting insulin to begin forming subcutaneous microprecipitates and establish basal coverage before IV insulin is withdrawn 1
• The transition should only occur when blood glucose levels have been stable for at least 24 hours and the patient is resuming oral feeding 1

Dose Calculation

• Calculate the Lantus dose based on the insulin infusion rate during the last 6 hours when stable glycemic goals were achieved 1
• A common approach: use half of the total 24-hour IV insulin dose as the once-daily Lantus dose 1
• Alternative method: if the hourly IV insulin rate is stable and less than 3 U/hour, this indicates readiness for transition 1
• For patients requiring ≥5 U/hour, this suggests major insulin resistance and may warrant delaying transition or adjusting dosing 1

Critical Timing Considerations

• Do not stop the IV insulin drip immediately after giving Lantus - the 2-hour window is essential 1
• Lantus has a 1-hour onset of action with no peak effect, requiring this overlap period to prevent a gap in insulin coverage 1
• Research demonstrates that administering glargine during IV insulin infusion (rather than after) reduces rebound hyperglycemia from 93.5% to 33.3% without increasing hypoglycemia risk 2

Additional Transition Components

Prandial Insulin Coverage

• If the patient is eating, add ultra-rapid insulin analogue at the first meal, using the other half of the 24-hour IV insulin dose divided by 3 meals 1
• Administer prandial insulin immediately before meals, or after meals if oral intake is uncertain 1
• Give only half the planned prandial dose if caloric intake is insufficient 1

Monitoring Requirements

• Maintain blood glucose monitoring every 4-6 hours initially after transition 3
• Target glucose levels of 140-180 mg/dL for most hospitalized patients 3
• If glucose falls below 100 mg/dL, decrease the Lantus dose by 10-20% 3

Common Pitfalls to Avoid

• Never discontinue IV insulin before giving subcutaneous basal insulin - this creates a dangerous gap in coverage and causes rebound hyperglycemia 1, 2
• Do not use sliding scale insulin alone as the transition strategy - this reactive approach increases complications compared to basal-bolus regimens 1
• Avoid premixed insulin formulations for inpatient transitions due to significantly increased hypoglycemia risk 1
• Do not base dosing solely on body weight without considering recent IV insulin requirements - the 6-hour stable infusion rate provides more accurate dosing 1

Special Patient Populations

• For type 1 diabetes patients, basal insulin coverage is mandatory even when NPO to prevent diabetic ketoacidosis 1, 3
• These patients require continuous basal insulin and cannot have any gap in coverage during the transition 1