Introduction
Thiazide diuretics have a role in the treatment of mild heart failure although loop diuretics are better for reducing overload. The main use of bendroflumethiazide was in the management of hypertension but recent NICE guidelines now recommend other thiazide-like diuretics such as indapamide and chlortalidone.
Mechanism of action
Thiazide diuretics work by inhibiting sodium reabsorption at the beginning of the distal convoluted tubule (DCT) by blocking the thiazide-sensitive Na+-Cl− symporter. Potassium is lost as a result of more sodium reaching the collecting ducts.
Adverse effects
- Dehydration
- Postural hypotension
- Hyponatraemia, hypokalaemia, hypercalcaemia*
- Gout
- Impaired glucose tolerance
- Impotence
Rare adverse effects
- Thrombocytopaenia
- Agranulocytosis
- Photosensitivity rash
- Pancreatitis