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PH7.1 | PH7.1 | Diabetes Mellitus Pharmacotherapy — SDL Guide — SDL Guide (Part 3)

Self-Assessment: Putting It Together

Use the following three clinical scenarios to test your pharmacological reasoning. For each, identify the recommended first add-on (beyond metformin), justify using mechanism and trial evidence, and note a drug to specifically avoid with the reason.

Scenario A: A 64-year-old woman, T2DM × 10 years, HbA1c 8.1%, eGFR 55, no cardiac history, BMI 28. She has had two hypoglycaemic episodes on her previous sulfonylurea.
Scenario B: A 48-year-old man, newly diagnosed T2DM, HbA1c 9.2%, BMI 36, no comorbidities, motivated for lifestyle change. Wants to avoid injections.
Scenario C: A 70-year-old man, T2DM × 15 years, HbA1c 7.8%, eGFR 28, HFrEF (LVEF 35%), on ACE inhibitor and carvedilol. Currently on metformin 1000 mg BD.

Answers:
A: Sitagliptin (DPP-4i — renal-safe at this eGFR, dose-neutral, no hypoglycaemia) or empagliflozin (eGFR 55 supports glycaemic indication, cardio-renal benefit). Avoid glibenclamide (long-acting, repeat hypoglycaemia risk).
B: Metformin + oral semaglutide (Rybelsus — GLP-1 RA, oral, weight loss 3–5 kg, avoids injection). If cost is a barrier: metformin + pioglitazone (weight gain caveat). Avoid SU (weight-gaining, hypoglycaemia).
C: Stop metformin (eGFR 28 < threshold of 30 — lactic acidosis risk). Add empagliflozin or dapagliflozin (cardio-renal dose, HFrEF benefit, eGFR 28 allows continuation to ~20). Avoid saxagliptin (HHF risk, SAVOR-TIMI). Avoid pioglitazone (worsens HF).