Co-amilofruse

How it works

Furosemide inhibits the sodium-potassium-chloride co-transporter in the loop of Henle to produce a brisk diuresis, while amiloride blocks distal epithelial sodium channels to limit potassium loss.

Prescribing in practice

• Monitor for hyperkalaemia, which can be precipitated by the amiloride component especially in renal impairment or with ACE inhibitors, ARBs or potassium supplements.
• The combination can cause hypotension, dehydration and other electrolyte disturbances such as hyponatraemia.
• Use with caution in renal impairment and avoid concurrent potassium-sparing diuretics or potassium supplements.

Monitoring

Monitor serum electrolytes, particularly potassium and sodium, alongside renal function and fluid status.

Counselling the patient

• Take the dose earlier in the day to avoid disturbed sleep from passing urine.
• Report muscle weakness, palpitations, confusion or excessive thirst.
• Avoid potassium-containing salt substitutes unless advised otherwise.

Evidence & guidelines

Loop diuretics are an established symptomatic treatment for fluid overload; the potassium-sparing combination reflects standard UK practice to mitigate diuretic-induced hypokalaemia.