Ethacrynic acid effects on the isolated inner ear: evaluation of the ototoxic potential in an organ culture system.

The ototoxic potential of ethacrynic acid, defined as causing morphologic damage to hair cells or adjacent supporting structures, was analyzed in an organ culture model exposing inner ear structures to concentrations attainable during clinical conditions (0.1 to 10 micrograms/ml). In low doses more) ethacrynic acid caused generalized toxic effects on the tissue morphology of many types of inner ear tissues and an arrest of tissue differentiation. Although by definition ethacrynic acid is an ototoxic agent, there is, at least in the in vitro system, a very narrow dose range between the selective hair cell damaging concentration and that causing generalized toxic effects.