Etacrynic acid (INN) or ethacrynic acid (USAN), trade name Edecrin, 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.
Etacrynic acid is a phenoxyacetic acid derivative containing a ketone and a methylene group. A cysteine adduct is formed with the methylene group and this is the active form.
Read more about Etacrynic Acid: Administration, Adverse Effects, Mechanism of Action