| Mechanism of action |
Blocks SGLT‑2 in the proximal tubule of the kidney → ↓ glucose re‑absorption → ↑ urinary glucose excretion (glycosuria) |
Metformin ↓ hepatic glucose production; sulfonylureas stimulate insulin release; GLP‑1‑RA increases glucose‑dependent insulin release, suppresses glucagon, slows gastric emptying |
Directly provides insulin to the bloodstream |
Same renal mechanism but different pharmacokinetics and slightly different safety signals |
| Site of action |
Kidney (renal tubular cells) |
Pancreas, liver, gut |
Pancreas or external delivery |
Kidney |
| Effect on blood pressure |
Mild reduction (~2–5 mm Hg systolic) |
Metformin minimal; sulfonylureas none; GLP‑1‑RA modest |
None |
Similar mild reduction |
| Weight effect |
Slight weight loss (≈1–2 kg on average) due to calorie loss in urine |
Metformin → slight loss; sulfonylureas → weight gain; GLP‑1‑RA → weight loss |
Neutral or gain (depending on dosing) |
Similar weight‑loss effect |
| Cardiovascular benefit |
Proven 38 % reduction in CV death & 35 % reduction in heart‑failure hospitalization (EMPA‑REG OUTCOME) |
GLP‑1‑RAs (liraglutide, semaglutide) show CV benefit; metformin modest |
No specific CV benefit |
Dapagliflozin & canagliflozin also show heart‑failure & CKD benefits |
| Kidney benefit |
Slows progression of diabetic kidney disease; reduces albuminuria |
Metformin contraindicated in advanced CKD; sulfonylureas neutral; GLP‑1‑RA neutral |
Neutral |
Dapagliflozin & canagliflozin have similar CKD‑protective effects |
| Common side‑effects |
Genital mycotic infections (vaginal or urinary), genital pruritus, mild hypoglycemia (rare when used alone), possible ketoacidosis, mild volume depletion, ↑ LDL‑C |
Metformin: GI upset, lactic acidosis (rare); sulfonylureas: hypoglycemia; GLP‑1‑RA: GI upset, pancreatitis risk |
Hypoglycemia, weight gain, edema, injection‑site reactions |
Similar genital infections, ketoacidosis, volume depletion |
| Contraindications |
Type 1 diabetes, diabetic ketoacidosis, severe renal impairment (eGFR < 45 ml/min), pregnancy |
Metformin: renal impairment, heart failure; sulfonylureas: hypoglycemia risk in renal disease |
Severe hypoglycemia risk, pregnancy (category B) |
Similar renal limits, pregnancy |
| Unique “off‑label” benefits |
Can be used for heart‑failure with reduced ejection fraction (HFrEF) and chronic kidney disease even in non‑diabetic patients (per EMPEROR‑HF, DAPA‑HF trials) |
GLP‑1‑RA used for weight management |
N/A |
Dapagliflozin also approved for HFrEF |