From the Guidelines
Amiloride is indicated for hypertension management primarily as an add-on therapy when patients are already taking other diuretics that cause potassium loss, particularly thiazide or loop diuretics, and should be considered after other options have been exhausted, such as spironolactone, eplerenone, or beta-blockers, in patients with resistant hypertension 1. The usual dosage is 5-10 mg daily, which can be given as a single dose or divided into two doses. Amiloride works by blocking sodium channels in the distal tubule of the kidney, which reduces sodium reabsorption while sparing potassium. This mechanism makes it particularly useful for patients who have hypokalemia or are at risk for developing low potassium levels due to other diuretic therapy. Some key points to consider when using amiloride include:
- It is not typically used as first-line monotherapy for hypertension, but rather as part of a combination therapy regimen 1.
- Regular monitoring of serum potassium, sodium, and renal function is essential, as hyperkalemia is a significant risk, especially in patients with renal impairment or those taking other potassium-sparing medications or supplements 1.
- Amiloride should be avoided in patients with significant renal dysfunction (creatinine clearance <50 mL/min), severe hyperkalemia (>5.5 mEq/L), or those taking other potassium-sparing agents like ACE inhibitors, ARBs, or spironolactone without careful monitoring 1.
- The 2024 ESC guidelines recommend considering amiloride as a fifth-line treatment option for resistant hypertension, after other agents such as spironolactone, eplerenone, and beta-blockers have been tried 1.
From the FDA Drug Label
Amiloride HCl is indicated as adjunctive treatment with thiazide diuretics or other kaliuretic-diuretic agents in congestive heart failure or hypertension to: a. help restore normal serum potassium levels in patients who develop hypokalemia on the kaliuretic diuretic b prevent development of hypokalemia in patients who would be exposed to particular risk if hypokalemia were to develop, e.g., digitalized patients or patients with significant cardiac arrhythmias.
Amiloride is indicated for use in patients with hypertension as an adjunctive treatment with thiazide diuretics or other kaliuretic-diuretic agents to:
- Help restore normal serum potassium levels in patients who develop hypokalemia
- Prevent development of hypokalemia in patients who would be exposed to particular risk if hypokalemia were to develop, such as digitalized patients or patients with significant cardiac arrhythmias. It should rarely be used alone due to the risk of hyperkalemia 2.
From the Research
Indications for Amiloride Use
Amiloride is a potassium-sparing diuretic that can be used in various clinical settings, including:
- Oedematous states
- Hypertension, particularly as an adjunct to thiazide or loop diuretics for potassium conservation
- Congestive heart failure
- Hepatic cirrhosis with ascites
Use in Hypertension
Amiloride can be used in patients with hypertension, especially:
- In combination with thiazide diuretics to counteract the adverse metabolic effects of thiazides 3
- In resistant hypertension, where it has been shown to be as effective as spironolactone 3
- As a fixed-dose combination with hydrochlorothiazide for essential hypertension 4
Important Considerations
When using amiloride, it is essential to:
- Monitor serum potassium levels to avoid hyperkalemia, particularly in patients with renal impairment or those taking other medications that can increase potassium levels 5, 6
- Be cautious in elderly patients with renal impairment, as potassium-sparing diuretics may cause renal failure, sometimes secondary to hypovolaemia 7
- Consider the potential interactions with other medications, such as non-steroidal anti-inflammatory drugs (NSAID), which may potentiate the effects of amiloride 7