IM11.{16-18,21} | Diabetes Pharmacologic Management — Summary & Reflection

KEY TAKEAWAYS

Diabetes pharmacotherapy is mechanism-driven and outcome-directed. Drug classes: Metformin (biguanide, AMPK activation, hepatic glucose, first-line, avoid eGFR <30); SU (SUR1 channel, insulin secretagogue, hypoglycaemia + weight gain, avoid glibenclamide in CKD); TZD/pioglitazone (PPARγ, insulin sensitiser, fluid retention + heart failure contraindication); DPP-4i (incretin potentiation, weight-neutral, safe in CKD — use linagliptin); GLP-1 RA (incretin mimetic, weight loss, CV benefit in ASCVD — avoid if pancreatitis/MTC history); SGLT2i (glycosuria, renal/CV/HF benefit, genital mycotic infections, euglycaemic DKA risk, avoid T1DM); insulin (various types, hypoglycaemia + weight gain).

T2DM algorithm: Lifestyle first → metformin ± comorbidity-driven co-prescription (SGLT2i for CKD/HF; GLP-1 RA for CVD/obesity) → add second agent if HbA1c not at target → triple therapy → basal insulin.

Organ protection: ACEi/ARB for nephropathy and hypertension (target BP <130/80; do NOT combine); statins for dyslipidaemia (high-intensity if ASCVD, LDL-C <1.8 mmol/L); aspirin for secondary prevention; duloxetine/pregabalin for painful neuropathy; anti-VEGF + PRP for retinopathy.

Patient-centred factors (IM11.21): Cost, injection aversion, hypoglycaemia risk, weight, comorbidities, and patient values all inform drug choice — evidence-based prescribing and patient-acceptable prescribing must both be achieved.

REFLECT

Return to Rajan from the opening hook. He has eGFR 58, ACR 42 mg/mmol (macroalbuminuria), LDL-C 3.4, BP 148/92, BMI 29, no prior CVD, and a preference for oral medication. You now have the pharmacological framework to prescribe for him: add an SGLT2 inhibitor (renal protection + glycaemic lowering + BP lowering + modest weight loss — addresses most of his problems simultaneously), start an ACEi or ARB (nephroprotection + BP control — but check K+ and creatinine in 2 weeks), intensify statin therapy to achieve LDL-C <2.6 (or lower if you consider his CKD an independent CVD risk equivalent). His reluctance about injections is respected — SGLT2i is oral. His concern about tablet burden is addressed by explaining that each additional drug treats a specific complication risk, not just glucose. This is patient-centred pharmacotherapy: evidence-based, organ-protective, affordable, and aligned with the patient's values. Think about how you would explain the reason for each drug to Rajan in language he can understand — because the best prescribed drug is the one the patient actually takes.