Thiazide Diuretics

Key points

• MOA: inhibit Na⁺ reabsorption at the start of the distal convoluted tubule (block thiazide-sensitive Na⁺-Cl⁻ symporter); K⁺ lost as more Na⁺ reaches collecting ducts.
• NICE now recommends thiazide-like diuretics indapamide and chlortalidone over bendroflumethiazide for hypertension.
• Common adverse effects: dehydration · postural hypotension · hyponatraemia · hypokalaemia · hypercalcaemia · gout · impaired glucose tolerance · impotence.
• Rare: thrombocytopenia · agranulocytosis · photosensitivity rash · pancreatitis.
• Hypocalciuria may reduce renal-stone incidence.