Amiloride hydrochloride dihydrate (Amiloride HCl dihydrate) is a pyrazine compound inhibiting SODIUM reabsorption through SODIUM CHANNELS in renal EPITHELIAL CELLS. This inhibition creates a negative potential in the luminal membranes of principal cells, located in the distal convoluted tubule and collecting duct. Negative potential reduces secretion of potassium and hydrogen ions. Amiloride hydrochloride dihydrate is used in conjunction with DIURETICS to spare POTASSIUM loss.

Amiloride inhibits autophosphorylation of the EGF receptor and induces dephosphorylation of phosphoinositide 3-kinase, phosphoinositide-dependent kinase-1, PTEN (phosphatase and tensin homolog deleted on chromosome ten), and PP1 alpha phosphatase. It also blocks the adhesion of HL-60 cells induced by phorbol ester (where adhesion indicates a differentiated state), unlike dimethylamiloride (and EIPA, another Amiloride-like effective drug). In intact rabbit proximal tubules, Amiloride reduces oxygen consumption sensitive to ouabain in the presence of extracellular sodium at varying concentrations.