Type 2 Diabetes with CKD, Hypoglycemia, and a Contrast Procedure Next Week

Stop glipizide; reduce metformin to no more than 1000 mg total per day; target A1c roughly 7.5-8.0%.

Reasoning:

• Glipizide: sulfonylureas cause hypoglycemia, and the risk rises steeply as eGFR falls because the drug and its metabolites accumulate. She has already had two documented symptomatic episodes, which in an older adult with CKD is a fall, fracture, and arrhythmia risk. Stop it rather than reduce it - she has other options.
• Metformin: at eGFR 30-45, metformin should not be newly started and should be continued only with dose reduction and review; commonly the total daily dose is capped around 1000 mg. The risk being managed is lactic acidosis with accumulating drug. Stop entirely if eGFR falls below 30.
• A1c target: an A1c of 9.3% needs to come down, but not to 6.5%. In an older patient with CKD, hypoglycemia history, and cardiovascular disease, a target of roughly <8% (individualized 7.5-8.0%) balances microvascular benefit against hypoglycemia harm. Chasing a low A1c here would cause harm.
• She is maximally dosed on ACE inhibitor already - do not add an ARB on top; that combination raises hyperkalemia and AKI risk without benefit.

Add an SGLT2 inhibitor, and be prepared to add a GLP-1 agonist later if her A1c does not reach target.

Reasoning:

• Her dominant risk profile is CKD with albuminuria (UACR 340 mg/g = A3) plus high cardiovascular risk. SGLT2 inhibitors slow eGFR decline and reduce progression to dialysis and heart failure hospitalization in albuminuric diabetic kidney disease, independent of glucose lowering. That is an organ-protective indication, not merely a glucose-lowering one.
• eGFR threshold: SGLT2 inhibitors can be initiated down to an eGFR of about 20 mL/min/1.73 m² (label thresholds vary slightly by agent), and once started they may be continued until dialysis or transplant. At 36 she is comfortably above the threshold.
• Expect a small, reversible "dip" in eGFR of a few points in the first weeks - this is hemodynamic, not injury, and is not a reason to stop.
• Counsel on genital mycotic infections, volume depletion (particularly with her ACE inhibitor), and euglycemic DKA - and on sick-day rules to hold the drug during acute illness, prolonged fasting, or before surgery.
• GLP-1 agonists are the better choice if weight loss or atherosclerotic cardiovascular risk dominates, or if A1c remains above target; they can be combined with an SGLT2 inhibitor. GLP-1 agents are generally avoided with a personal/family history of medullary thyroid carcinoma or MEN2.

Hold metformin and the SGLT2 inhibitor around contrast, hydrate, and recheck renal function afterward. The dangerous mistake is allowing euglycemic DKA or metformin-associated lactic acidosis to develop in a patient with an eGFR of 36.

Plan:

• Metformin: hold at the time of the procedure (commonly 48 hours before, or at minimum on the day of) and restart only after 48 hours, provided renal function is stable and there is no other AKI risk. With a baseline eGFR of 36 she has little reserve.
• SGLT2 inhibitor: hold about 3-4 days before an elective procedure. The concern is euglycemic diabetic ketoacidosis - glucose can be near normal while ketones are high, so a normal glucose does not reassure you. Do not restart until she is eating and volume status is normal.
• Prevention of contrast-associated AKI: ensure adequate hydration, avoid concomitant NSAIDs, hold other nephrotoxins, and avoid repeating contrast too soon.
• Check a basic metabolic panel (creatinine, potassium, bicarbonate) 48-72 hours after the procedure - and check ketones if she develops nausea, vomiting, or abdominal pain, regardless of glucose.
• Since she is going to the cath lab, ask whether the angiogram will be followed by revascularization; if so, plan the diabetes regimen around the likely admission rather than around an outpatient schedule.