Amiloride

Amiloride is a **potassium-sparing diuretic** that is typically used in combination with other, more potent diuretics (such as furosemide or thiazides) to manage edema and ascites while preventing excessive potassium loss. Because it is a weak diuretic when used alone, its primary clinical value lies in its ability to mitigate the hypokalemia often caused by loop diuretics. > **Clinical Warning:** Can cause life-threatening hyperkalemia if used inappropriately, especially in patients with renal impairment or those receiving ACE inhibitors. **Clinical Pearl:** Often formulated as a compound preparation (e.g., co-amilofruse) to balance potassium excretion and retention in chronic heart failure management.

Mechanism: Amiloride acts directly on the **distal convoluted tubule** and **collecting duct** of the nephron. It blocks epithelial sodium channels (ENaC) → inhibits sodium absorption → decreases the electrical potential across the tubular epithelium → reduces the driving force for potassium and hydrogen ion secretion. This leads to a failure of the normal renal concentration gradient, resulting in **sodium loss** (mild diuresis) and **potassium retention**.

VetSheet drug reference is intended for licensed veterinary professionals as a clinical decision-support aid, not a substitute for professional judgement or the manufacturer’s current label.