Can someone explain how ethacrynic acid causes deafness?
Na+K+Cl+ transporter is also present in the ear. This transporter is the main site of action for ethacrynic acid. So when it acts the transporter Is inhibited leading to ionic imbalance. This results in hearing loss.
It is the diuretic which is most dangerous when it comes to causing sensorineural deafness.
Even then it's use indicated in one special condition. Guess which condition?
If a patient has reaction to sulpha drugs.. The DOC becomes ethacrynic acid.
Recent studies revealed that the ototoxic effect of EA is actually involved in selectively blocking the lateral spiral artery in the cochlea and suppressing the blood flow supply to the cochlear lateral wall. The epithelial ischemia and anoxia in stria vascularis resulted in a significant depression of endolymphatic potential which was equivalent to cutting off the power supply of the cochlea . During the ischemic damage to the epithelium and capillaries on the cochlear lateral wall, the vascular permeability and membranous permeability in stria vascularis were also affected so that the ototoxic drug can penetrate through the broken blood-cochlea barrier to enter the cochlea.the ototoxic drug can reach the cochlear hair cells either through the cuticular plate facing the endolymph or through the under parts of the hair cells in the cortilymph.
In short bro, hair cell damage directly by EA.
Oooh. So it first causes ischemia and then enters the hair cells. But at the end the outer hair cells are getting damaged. Nice!