Diuretics are useful for managing oedema due to heart failure or kidney or liver disease. Thiazides or loop diuretics are recommended in chronic heart failure and can be used in combination if there is insufficient response to monotherapy. However, the BNF warns that if too much urine is produced quickly, which may occur particularly with loop diuretics, the patient may become hypotensive.^5,29,30

Spironolactone may be preferred for patients with liver disease and secondary hyperaldosteronism, possible with furosemide.^5,30

Oedema caused by amlodipine and other dihydropyridine CCBs is unlikely to respond to diuretics even if a lot of sodium is excreted and plasma volume decreases. Thiazides and loop diuretics reduce water retention only and do not stop fluid from pooling due to vasodilation. Adding a thiazide to counteract amlodipine oedema might also cause hyponatraemia.^14,31,32

For insulin-related oedema, management approaches include restricting salt and fluid intake, titrating the insulin dose, or using diuretics such as furosemide or adrenergics.²⁵