In an 83-year-old patient with type 2 diabetes mellitus who is taking insulin glargine (Lantus) 10 units at bedtime and empagliflozin (Jardiance) 10 mg daily, with blood glucose persistently in the 200–300 mg/dL range, should the insulin dose, the empagliflozin dose, or both be increased?

Increase the Insulin Dose First, Then Consider Empagliflozin Dose Escalation

In this 83-year-old patient with blood glucose persistently in the 200-300 mg/dL range on Lantus 10 units and Jardiance 10 mg, prioritize increasing the basal insulin dose using a systematic titration protocol, as the current insulin dose is markedly suboptimal for glycemic control.

Primary Recommendation: Insulin Titration

The current Lantus dose of 10 units is insufficient for this patient's glycemic control. According to ADA guidelines, basal insulin should be titrated systematically to achieve fasting glucose targets 1.

Specific titration approach:

• Increase Lantus by 2-4 units once or twice weekly until fasting blood glucose reaches 90-150 mg/dL (given the patient's age, a more relaxed target of 90-150 mg/dL is appropriate rather than <100 mg/dL) 1, 2
• Alternatively, increase by 10-15% of the current dose weekly 1
• For elderly patients (≥70 years), guidelines recommend starting calculations at 0.2-0.3 units/kg, which for most patients would exceed 10 units 3

The patient's glucose levels in the 200-300s indicate the basal insulin is dramatically undertitrated. This is the primary problem that must be addressed first.

Secondary Consideration: Empagliflozin Dose

After optimizing basal insulin, consider increasing Jardiance from 10 mg to 25 mg daily. The maximum approved dose of empagliflozin is 25 mg, which provides additional glycemic benefit beyond the 10 mg dose 4. In a study of patients on multiple daily insulin injections with mean baseline HbA1c of 8.3%, empagliflozin 25 mg reduced HbA1c by an additional 0.5% compared to placebo while actually reducing insulin requirements by 11-13 units/day 4.

Why Insulin Takes Priority

1. Magnitude of hyperglycemia: Blood glucose in the 200-300s reflects severe basal insulin deficiency that cannot be adequately addressed by SGLT2 inhibitor dose escalation alone

2. Elderly patient considerations: In patients ≥83 years, the 2023 ADA guidelines emphasize that basal insulin remains the cornerstone of therapy, with a target fasting glucose of 90-150 mg/dL being appropriate 2, 5

3. SGLT2 inhibitor limitations: While empagliflozin 25 mg provides incremental benefit over 10 mg (approximately 0.1-0.2% additional HbA1c reduction), this modest improvement cannot compensate for grossly inadequate basal insulin dosing 4

Practical Algorithm

Week 1-4:

• Increase Lantus by 2-4 units every 3-7 days based on fasting glucose readings
• Continue Jardiance 10 mg
• Monitor for hypoglycemia (though unlikely given current glucose levels)
• Target fasting glucose: 90-150 mg/dL

Week 4-8 (if fasting glucose controlled but overall control inadequate):

• Once fasting glucose approaches target, increase Jardiance to 25 mg daily
• This combination provides synergistic benefit: insulin addresses basal glucose production while empagliflozin increases urinary glucose excretion 4

Ongoing:

• If glucose remains elevated despite optimized basal insulin (>0.5 units/kg/day) and maximum SGLT2 inhibitor dose, consider adding prandial insulin coverage 1

Critical Safety Considerations for This Elderly Patient

1. Hypoglycemia risk: While increasing insulin, educate on hypoglycemia recognition. However, given current glucose levels (200-300s), immediate hypoglycemia risk is low 2

2. Volume depletion with SGLT2 inhibitors: Empagliflozin carries increased risk of volume depletion in patients ≥75 years 6. Ensure adequate hydration when escalating to 25 mg

3. Ketoacidosis monitoring: Though rare with empagliflozin in type 2 diabetes, educate on symptoms (nausea, vomiting, abdominal pain) 1

4. Renal function: Verify eGFR ≥45 mL/min before increasing empagliflozin dose (though 10 mg can be used down to eGFR 30)

5. Avoid overbasalization: If insulin requirements exceed 0.5 units/kg/day without achieving control, this signals need for prandial coverage rather than further basal insulin escalation 7

Why Not Increase Both Simultaneously?

Increasing both medications simultaneously makes it impossible to determine which intervention caused any observed changes (beneficial or adverse). Sequential titration allows for:

• Clear attribution of glycemic improvement
• Identification of which medication caused any adverse effects
• More conservative approach appropriate for an elderly patient
• Better patient education and adherence with stepwise changes

The insulin dose is the primary deficiency here—address this first with aggressive but safe titration, then optimize the SGLT2 inhibitor dose as a complementary strategy.