It is unknown if amiloride can be dialyzed off, and no specific antidote against it exists. Treatment is generally supportive, though hyperkalemia can be treated. Interactions
Amiloride may have important drug-drug interactions when combined with other medications that also increase potassium levels in the blood, leading to hyperkalemia. For example, the combination of amiloride with angiotensin-converting enzyme (ACE) inhibitors like lisinopril, or angiotensin II receptor type 1 (AT1) antagonists like losartan, may lead to high levels of potassium in the blood, requiring frequent monitoring. Pharmacology
Mechanism of action
Diuresis
Amiloride works by directly blocking the epithelial sodium channel (ENaC) with an IC50 around 0.1 μM, indicating potent blockade. Antagonism of ENaC thereby inhibits sodium reabsorption in the late distal convoluted tubules, connecting tubules, and collecting ducts in the nephron. This promotes the loss of sodium and water from the body, and reduces potassium excretion. The drug is often used in conjunction with a thiazide diuretic to counteract with a potassium-losing effect. Due to its potassium-sparing capacities, hyperkalemia (elevated potassium concentration in the blood) can occur. The risk of developing hyperkalemia is increased in patients who are also taking ACE inhibitors, angiotensin II receptor antagonists, other potassium-sparing diuretics, or any potassium-containing supplements. Miscellaneous
A fraction of the effects of amiloride is inhibition of cyclic GMP-gated cation channels in the inner medullary collecting duct.Amiloride has a second action on the heart, blocking Na+/H+ exchangers sodium–hydrogen antiporter 1 or NHE-1.
Amiloride, sold under the trade name Midamor among others, is a medication typically used with other medications to treat high blood pressure or swelling due to heart failure or cirrhosis of the liver. Amiloride is classified as a potassium-sparing diuretic. Amiloride is often used together with another diuretic, such as a thiazide or loop diuretic. It is taken by mouth. Onset of action is about two hours and it lasts for about a day.Common side effects include high blood potassium, vomiting, loss of appetite, rash, and headache. The risk of high blood potassium is greater in those with kidney problems, diabetes, and those who are older. Amiloride blocks the epithelial sodium channel (ENaC) in the late distal tubule, connecting tubule, and collecting duct of the nephron, which both reduces absorption of sodium ion from the lumen of the nephron and reduces excretion of potassium ion into the lumen.Amiloride was developed in 1967. It is on the World Health Organizations List of Essential Medicines. Medical uses
Amiloride may be used in combination with a thiazide diuretic for treatment of high blood pressure or (less commonly) in combination with a loop diuretic for treatment of heart failure. The potassium-sparing effects of amiloride offset the low blood potassium (hypokalemia) that is often induced by thiazides or loop diuretics, which is of particular importance in people for whom maintaining a normal level of potassium is critically important. For example, people that are taking Digitalis (i.e.