Oral antidiabetic drugs

Biguanides

e.g. metformin
How it works: ↓ gluconeogenesis, ↓ hepatic glucose production, ↑ peripheral glucose uptake – requires endogenous insulin (reduces basal hyperinuslinaemia)
Advantages: CV protection, weight loss
Contraindications: eGFR<35 as excreted renally
Adverse effects: GI upset, lactic acidosis

Sulphonylurea

e.g. gliclazide
How it works: block beta islet cell K+ channels ⇒ stimulates insulin secretion (requires residual beta cell function!)
Advantages:
Contraindications: dose change in CKD. CI in G6PD def
Adverse effects: hypos (esp with ↓ renal fx), weight gain, GI upset, SIADH, cholestasis

SGLT-2 inhibitors (-gliflozin)

Dapagliflozin, empagliflozin - risk of euglycaemic DKA hence hold when unwell
How it works: SGLT-2 inhibitor ⇒ ↓ renal glucose reabsorption ⇒ glycosuria
Advantages: CV protection, weight loss, may preserve renal fx
Contraindications: hepatic impairment or eGFR <60
Adverse effects: UTI, ↑ infection, ↓ BP, hypos, dyslipidaemia, ⚠ euglycaemic DKA, Fournier's gangrene

GLP-1 analogues → has its own page due to increasing popularity in recent years!

Thiazolidonediones

e.g. glitazone
How it works: PPAR-gamma agonist ⇒ ↑ peripheral insulin sensitivity, ↑ muscle glucose uptake
Advantages:
Contraindications: congestive heart failure
Adverse effects: hypos, #, fluid retention, bladder cancer