Decision support only — not a substitute for the ADA Standards, the Australian ADS/RACGP algorithm, eTG, or your endocrine/renal team. The modern shift: choose agents by what you're protecting (heart, kidney, weight), independent of HbA1c — not by glucose alone. Verify every dose and PBS criterion.
1 Choose the agent by what you're protecting
Foundation — everyoneregardless of comorbidity
Lifestyle + weight management. Individualised HbA1c target.
Metformin first-line for most (unless contraindicated) — but add an organ-protective agent for the indications below regardless of HbA1c.
ASCVD / high CV riskor ≥55 + risk factors
Established atherosclerotic disease or multiple risk factors.
GLP-1 RA or SGLT2i with proven CV benefit. Combination may further cut MACE and kidney events.
Heart failureHFrEF or HFpEF
Established HF, either ejection fraction.
SGLT2i (proven HF benefit). For obesity + symptomatic HFpEF, a GLP-1 RA / GIP-GLP-1 reduces symptoms.
CKDalbuminuria, low eGFR
Diabetic kidney disease — check uACR + eGFR.
SGLT2i + ACEi/ARB. Add finerenone if albuminuria persists. GLP-1 RA also renoprotective.
Obesity-predominantweight is the lever
Weight driving the metabolic picture.
GLP-1 RA or tirzepatide (GIP/GLP-1) — weight + glucose + CV. ~15% loss can drive remission (DiRECT).
Metformin isn't mandatory-first when there's a compelling cardiorenal indication — lead with (or add) the organ-protective agent. PBS catch (AU): GLP-1 RA + SGLT2i isn't subsidised together for T2D; the combination is only PBS-funded when the SGLT2i is prescribed under a CKD or HF code. Confirm before prescribing.
2 Targets & the foundation
Individualise the HbA1c
- General≤7% (53 mmol/mol) for most.
- Tighter~6.5% (48) if achievable without hypos — younger, short duration, low-hypo agents.
- Relax≤8% (64) in frailty, limited life expectancy, hypo-prone, established complications.
- ACCORDTight isn't always better — intensive control raised mortality in high-risk patients. Early control has legacy benefit (UKPDS); late intensification doesn't.
Where the long game is won
- WeightA primary target, not a side issue. ~15% loss can induce remission.
- DietSustainable quality patterns (Mediterranean, plant-based); cut ultra-processed — over rigid calorie counting.
- DSMESStructured education + activity. The behaviours outlast any single drug.
3 The agents at a glance
Organ-protective — reach for these
- SGLT2iEmpa/dapagliflozin. CV + HF + renal benefit; weight loss; low hypo. Euglycaemic DKA, genital mycotic infection, volume depletion, Fournier's.
- GLP-1 RASemaglutide, dulaglutide. Weight + glucose + CV. GI upset; pancreatitis caution; contraindicated in MTC/MEN2.
- TirzepatideGIP/GLP-1 — strongest weight + glucose effect.
- FinerenoneNonsteroidal MRA for diabetic CKD + albuminuria. Watch hyperkalaemia.
Glucose-focused / older
- MetforminFoundational, cheap, weight-neutral. GI, B12; avoid eGFR <30, unstable HF, around contrast.
- SulfonylureaGliclazide — effective & cheap but hypos + weight gain. Deprioritise.
- DPP-4iWeight-neutral, modest, no CV benefit. Don't combine with a GLP-1 RA.
- Insulin / TZDInsulin if symptomatic/very high HbA1c/catabolic (basal first; hypos/weight). Pioglitazone: MASH/IR niche; HF/oedema/fracture caution.
4 The traps worth knowing cold
SGLT2i & euglycaemic DKA
- WhyCan be ketoacidotic with near-normal glucose — easily missed.
- Sick daysStop when acutely unwell, fasting, or pre-surgery.
- PeriopWithhold ~3 days before surgery.
GLP-1 RA & the airway
- RiskDelayed gastric emptying → aspiration under anaesthesia/sedation.
- HoldBefore anaesthesia/endoscopy — day-of for daily agents, ~1 week for weekly.
Don't get caught
- HyposSU + insulin drive hypoglycaemia & weight gain — match agent to hypo risk.
- B12Check periodically on long-term metformin.
- DPP4+GLP1Same pathway — never together.
5 The rest of the risk — diabetes is a vascular disease
Treat the whole cardiovascular picture
- BP≤140/90 general; <130/80 with CKD or high CV risk. ACEi/ARB if albuminuria.
- LipidsStatin for most — intensity by absolute CV risk. Ezetimibe/PCSK9i if not at target.
- AntiplateletSecondary prevention only — not routine in primary prevention.
- Kidney stackAlbuminuria → ACEi/ARB + SGLT2i + finerenone, layered.
Screen the complications
- KidneyuACR + eGFR at least yearly.
- Eyes/feetRetinopathy screening; annual foot/neuropathy check.
- PreventSmoking cessation; vaccinate (flu, COVID, pneumococcal, RSV >60).
- ReviewDeintensify when over-treated, frail, or after substantial weight loss.
Sources.
ADA — Standards of Care in Diabetes 2025 & 2026 (comorbidity-driven SGLT2i/GLP-1 RA selection; CV, HF, CKD sections). ADA/EASD consensus on hyperglycaemia management. Australian Diabetes Society (ADS) Type 2 Diabetes Glycaemic Management Algorithm (Jun 2024) & RACGP "Management of type 2 diabetes: A handbook for general practice" (2025). KDIGO (diabetes + CKD). eTG; PBS for subsidy criteria.
Key trials: EMPA-REG/CANVAS/DECLARE & DAPA-HF/EMPEROR (SGLT2i CV-HF); LEADER/SUSTAIN-6/REWIND (GLP-1 RA CV); SURPASS/SURMOUNT (tirzepatide); FIDELIO/FIGARO (finerenone); CREDENCE/DAPA-CKD (renal); ACCORD (intensive-control harm); UKPDS (legacy effect); DiRECT (remission).
Caveats: PBS governs which agents/combinations are subsidised — notably GLP-1 RA + SGLT2i for T2D. HbA1c targets are a guide, individualised to hypo risk and life expectancy. Verify all doses, renal cut-offs, and contraindications locally. Companion to the chronic-disease set.