Etacrynic Acid (EA)

Etacrynic acid is a loop diuretic used to treat high blood pressure and the swelling caused by diseases like congestive heart failure, liver failure, and kidney failure. Unlike the other loop diuretics, etacrynic acid is not a sulfonamide and thus, its use is not contraindicated in those with sulfa allergies. Ethacrynic acid is a phenoxyacetic acid derivative containing a ketone group and a methylene group. A cysteine adduct is formed with the methylene group and this is the active form. Ethacrynic acid acts by inhibiting sodium-potassium-chloride cotransport in the ascending loop of Henle. Loss of potassium ions is less marked but chances of hypochloremic alkalosis are greater. Ethacrynic acid and its glutathione-adduct are potent inhibitors of glutathione S-transferase family members, which are enzymes involved in xenobiotic metabolism. This family of enzymes has recently been shown to have a high rate of genetic variability.