Amiloride with Bumetanide

How it works

Bumetanide inhibits the sodium-potassium-chloride co-transporter in the thick ascending limb of the loop of Henle to produce a brisk diuresis, while amiloride blocks epithelial sodium channels in the distal nephron, reducing the potassium and hydrogen ion excretion that the loop component would otherwise cause.

Prescribing in practice

• The amiloride component can cause hyperkalaemia, so avoid combining with potassium supplements or other potassium-sparing agents and use caution with renal impairment, ACE inhibitors and angiotensin receptor blockers.
• Confirm a genuine need for the potassium-sparing element rather than defaulting to a fixed combination, since the bumetanide dose cannot be titrated independently.
• Loop diuresis can cause dehydration, postural hypotension and gout flares, so review volume status and use cautiously in the elderly.

Monitoring

Monitor renal function and serum electrolytes, particularly potassium and sodium, at baseline and periodically during treatment.

Counselling the patient

• Take in the morning to avoid disturbed sleep from increased urination.
• Avoid potassium-containing salt substitutes unless advised by your prescriber.
• Report muscle weakness, palpitations or marked dizziness.

Evidence & guidelines

Diuretic combinations of this type are long-established in UK practice for managing oedema while mitigating diuretic-induced hypokalaemia, consistent with current prescribing references.