What should be the new dose of Lantus (insulin glargine) and carb ratio for a stable adult patient with type 2 diabetes, currently on Lantus 8 units with a carb ratio of 1 per 8, and Jardiance (empagliflozin) 25 mg, which needs to be discontinued?

Adjusting Insulin Therapy After Jardiance Discontinuation

When discontinuing Jardiance 25 mg in a patient stable on Lantus 8 units with a 1:8 carb ratio, you should increase the Lantus dose by approximately 20-30% (to 10 units) and maintain the current carb ratio initially, then titrate based on glucose monitoring over the following week. 1, 2, 3

Immediate Dose Adjustment Algorithm

Basal Insulin (Lantus) Adjustment

• Increase Lantus from 8 units to 10 units once daily as an initial adjustment when discontinuing Jardiance 25 mg 1, 2, 3
• The rationale: Jardiance contributes approximately 70 grams of glucose excretion daily, which translates to meaningful glucose-lowering that must be replaced when discontinued 4
• This 20-30% increase accounts for the loss of SGLT2 inhibitor effect without overshooting into hypoglycemia 1, 3

Titration Protocol After Initial Adjustment

• Monitor fasting blood glucose daily for the first week after discontinuation to assess adequacy of the dose increase 2, 3
• If fasting glucose remains ≥140 mg/dL after 3 days, increase Lantus by an additional 2 units 1, 2, 3
• If fasting glucose is ≥180 mg/dL, increase by 4 units every 3 days until reaching target of 80-130 mg/dL 1, 2, 3
• Target fasting plasma glucose should be 80-130 mg/dL 1, 2, 3

Carbohydrate Ratio Management

Initial Approach to Carb Ratio

• Maintain the current 1:8 carb ratio initially (1 unit of rapid-acting insulin per 8 grams of carbohydrate) 1, 2
• The carb ratio primarily reflects prandial insulin needs, which are less directly affected by SGLT2 inhibitor discontinuation than basal requirements 1, 2

When to Adjust Carb Ratio

• Monitor postprandial glucose levels (2 hours after meals) for the first 1-2 weeks 1, 2, 3
• If postprandial glucose consistently exceeds 180 mg/dL despite adequate basal control, consider tightening the carb ratio to 1:7 (meaning more insulin per gram of carbohydrate) 1, 2
• Adjust the carb ratio by small increments (1:8 → 1:7 → 1:6) based on postprandial patterns, not daily recalculation 2

Critical Monitoring Requirements

First Week After Discontinuation

• Check fasting blood glucose every morning to guide basal insulin titration 2, 3
• Monitor pre-meal and 2-hour postprandial glucose at least once daily for each meal to assess prandial coverage 2, 3
• Watch for hypoglycemia (blood glucose <70 mg/dL), which would indicate excessive insulin adjustment 1, 2, 3

Hypoglycemia Management

• If hypoglycemia occurs without clear cause, reduce the Lantus dose by 10-20% immediately 1, 2, 3
• If more than 2 fasting glucose values per week are <80 mg/dL, decrease Lantus by 2 units 2, 3

Foundation Therapy Considerations

Metformin Continuation

• Ensure the patient remains on metformin (if not contraindicated) as the foundation of type 2 diabetes therapy, even when intensifying insulin 1, 3
• Metformin reduces insulin requirements and provides complementary glucose-lowering effects 3

Why Jardiance Is Being Discontinued

• Common reasons for SGLT2 inhibitor discontinuation include genital infections, volume depletion, acute kidney injury, or ketoacidosis risk 5, 6, 7
• Understanding the reason helps anticipate glucose patterns: if discontinued for infection/volume issues, glucose may rise more than if discontinued for other reasons 5, 7

Common Pitfalls to Avoid

Underestimating Glucose Rise

• Do not wait to see how glucose responds before adjusting insulin - proactive dose increase prevents days of hyperglycemia 1, 3
• Jardiance 25 mg typically reduces HbA1c by 0.5-0.8%, which translates to clinically significant glucose elevation when stopped 5, 7

Overadjusting Too Quickly

• Avoid increasing Lantus by more than 30% initially (i.e., don't go beyond 10-11 units as first adjustment) to prevent hypoglycemia 2, 3
• The glucose-lowering effect of Jardiance dissipates within 24-48 hours, but insulin adjustments should still be gradual 4, 5

Neglecting Weight and Blood Pressure Changes

• Anticipate 2-3 kg weight gain over the following weeks as glucose is no longer excreted in urine 5, 7
• Monitor blood pressure, as Jardiance provided 3-5 mmHg systolic BP reduction that will be lost 5, 7

Reassessment Timeline

Short-Term Follow-Up

• Reassess insulin doses after 1 week of daily glucose monitoring to determine if further titration is needed 2, 3
• Most patients will require at least one additional dose adjustment beyond the initial 20-30% increase 2, 3

Long-Term Monitoring

• Check HbA1c in 3 months to assess overall glycemic control after Jardiance discontinuation 1, 3
• If HbA1c remains above target despite optimized basal insulin, consider adding prandial insulin or a GLP-1 receptor agonist 1, 3