What is the next step in managing a 60‑year‑old woman with type 2 diabetes, diabetic neuropathy, hypertension, estimated glomerular filtration rate 73 mL/min/1.73 m², whose HbA1c increased from 6.9 % to 7.6 % despite Jardiance (empagliflozin) 10 mg daily and Mounjaro (tirzepatide) 15 mg subcutaneously weekly?

Escalate Tirzepatide to Maximum Dose Before Adding Basal Insulin

Your patient's HbA1c rose from 6.9% to 7.6% on Mounjaro 15 mg weekly plus Jardiance 10 mg daily, indicating inadequate glycemic control that warrants immediate intensification of the GLP-1/GIP receptor agonist before considering insulin initiation.

Immediate Medication Adjustment

• Increase Mounjaro (tirzepatide) from 15 mg to the maximum approved dose of 15 mg weekly—wait, you are already at 15 mg. The FDA-approved maximum dose is 15 mg weekly, so you have reached the ceiling for this agent. 1
• Because tirzepatide is already maximized at 15 mg weekly, the next step is to add basal insulin (insulin glargine or degludec) at 10 units once daily at bedtime while continuing both Mounjaro 15 mg weekly and Jardiance 10 mg daily. 1, 2
• Do not discontinue Mounjaro or Jardiance when adding basal insulin; the combination provides superior glycemic control with reduced insulin requirements (20–30% lower total daily insulin dose) and preserves the cardiovascular and renal protective benefits of both agents. 1, 3

Rationale for Adding Basal Insulin at This Stage

• An HbA1c of 7.6% exceeds the ADA target of <7.0% for most adults with type 2 diabetes, and the 0.7% rise over three months signals therapeutic failure of the current dual-agent regimen. 3
• Tirzepatide 15 mg weekly is the maximum approved dose; further dose escalation is not an option, so advancing to basal insulin is the evidence-based next step. 1, 2
• Basal insulin added to a GLP-1 receptor agonist (or dual GIP/GLP-1 agonist like tirzepatide) yields an additional 1.0–1.5% HbA1c reduction with minimal weight gain and lower hypoglycemia risk compared with basal-bolus insulin regimens. 3, 1
• The patient's eGFR of 73 mL/min/1.73 m² permits full-dose metformin (if not already on it), continued Jardiance 10 mg daily for cardiorenal protection, and unrestricted use of basal insulin. 3

Basal Insulin Initiation Protocol

• Start insulin glargine (Lantus, Basaglar, Toujeo) or insulin degludec (Tresiba) at 10 units subcutaneously once daily at bedtime (or 0.1–0.2 units/kg if the patient weighs significantly more or less than 50–100 kg). 2
• Titrate basal insulin by 2 units every 3 days if fasting glucose is 140–179 mg/dL, or by 4 units every 3 days if fasting glucose is ≥180 mg/dL, until fasting glucose consistently reaches 80–130 mg/dL. 2
• If any unexplained hypoglycemia (glucose <70 mg/dL) occurs, reduce the basal insulin dose by 10–20% immediately and reassess within 3 days. 2
• Stop basal insulin escalation when the dose approaches 0.5 units/kg/day (roughly 30–50 units for most adults); further increases beyond this threshold lead to "over-basalization" with higher hypoglycemia risk and suboptimal control. 2

Continuation of Jardiance and Tirzepatide

• Continue Jardiance (empagliflozin) 10 mg once daily for its proven cardiovascular and renal benefits, which include a 39% reduction in the composite of sustained eGFR decline, end-stage kidney disease, or cardiovascular/renal death. 3, 4
• Jardiance should not be discontinued when basal insulin is added; the combination is safe and provides additive cardiorenal protection independent of glycemic control. 3, 4
• Continue Mounjaro (tirzepatide) 15 mg weekly to maintain its glucose-lowering, weight-reducing, and cardiovascular protective effects; the combination of tirzepatide plus basal insulin is superior to basal-bolus insulin alone. 1

Monitoring and Titration Schedule

• Daily fasting glucose checks are essential during basal insulin titration to guide dose adjustments every 3 days. 2
• Recheck HbA1c in 3 months (at the next visit); if HbA1c remains >7.0% despite optimized basal insulin (fasting glucose 80–130 mg/dL), consider adding prandial insulin before the largest meal or switching to a basal-bolus regimen. 2
• Monitor eGFR and urine albumin-to-creatinine ratio annually to track diabetic kidney disease progression and adjust Jardiance dosing if eGFR falls below 25 mL/min/1.73 m². 3

Expected Clinical Outcomes

• Adding basal insulin to maximized tirzepatide should reduce HbA1c by an additional 1.0–1.5%, bringing the patient from 7.6% to approximately 6.1–6.6% within 3–6 months. 1, 2
• Weight gain with basal insulin is minimal (typically <2 kg) when combined with tirzepatide, which continues to promote weight loss or weight neutrality. 1
• Hypoglycemia risk remains low (<5% incidence) when basal insulin is properly titrated in combination with tirzepatide, as the GLP-1/GIP agonist provides glucose-dependent insulin secretion and glucagon suppression. 1

Common Pitfalls to Avoid

• Do not delay basal insulin initiation when HbA1c exceeds 7.0% on maximized tirzepatide; prolonged hyperglycemia increases the risk of microvascular complications. 3
• Do not discontinue Jardiance or Mounjaro when adding basal insulin; the combination provides superior outcomes compared with insulin monotherapy. 3, 1
• Do not escalate basal insulin beyond 0.5 units/kg/day without addressing postprandial hyperglycemia with prandial insulin; over-basalization leads to hypoglycemia without improved control. 2
• Do not use sliding-scale insulin as monotherapy in place of scheduled basal insulin; this reactive approach is condemned by major diabetes guidelines and leads to dangerous glucose fluctuations. 2

Alternative Option: Switch to a Different GLP-1 Receptor Agonist

• If the patient is intolerant to tirzepatide or prefers a different agent, consider switching to semaglutide 2.0 mg weekly (Ozempic) or dulaglutide 4.5 mg weekly (Trulicity), both of which provide comparable HbA1c reductions and cardiovascular benefits. 3, 1
• However, tirzepatide 15 mg weekly is the most potent glucose-lowering agent in the GLP-1/GIP class, so switching to another GLP-1 agonist is unlikely to provide additional benefit and may result in inferior glycemic control. 1

Patient Education Essentials

• Teach proper insulin injection technique (subcutaneous administration in the abdomen, thigh, or upper arm) and emphasize site rotation to prevent lipohypertrophy. 2
• Instruct the patient to recognize and treat hypoglycemia (symptoms include shakiness, sweating, confusion; treat with 15 g fast-acting carbohydrate, recheck in 15 minutes, repeat if needed). 2
• Advise the patient to withhold Jardiance during acute illness with reduced oral intake, fever, vomiting, or diarrhea to prevent euglycemic diabetic ketoacidosis. 4
• Counsel the patient that genital mycotic infections occur in approximately 6% of Jardiance users; daily hygiene reduces this risk. 4

Summary Algorithm

1. Confirm that Mounjaro is at the maximum dose of 15 mg weekly (it is).
2. Add basal insulin glargine or degludec 10 units once daily at bedtime while continuing Mounjaro 15 mg weekly and Jardiance 10 mg daily.
3. Titrate basal insulin by 2–4 units every 3 days based on fasting glucose until the target of 80–130 mg/dL is achieved.
4. Recheck HbA1c in 3 months; if still >7.0%, add prandial insulin before the largest meal or transition to basal-bolus therapy.
5. Monitor eGFR and UACR annually to track diabetic kidney disease progression.