A study of the ototoxicity of deferoxamine in chinchilla

Deferoxamine is a chelating agent used for the treatment of chronic iron overload in patients requiring long-term blood transfusions. Audiological testing of patients with B-thalassemia major and steroid-unresponsive Diamond-Blackfan anemia who were on long-term deferoxamine treatment indicated a possible ototoxic side-effect. In the present study we have investigated this potential toxicity to the cochlea of experimental animals by monitoring electrophysiological responses to sound and also by histological evaluation of the cochlea. In animals having chronic deferoxamine treatment, there were no significant changes in cochlear function or morphology. Data from acutely treated animals indicated an elevation of cochlear response thresholds together with morphological changes at the inner hair-cell level. However, these changes were highly correlated with the respiratory depression caused by an acute general toxicity, rather than a direct ototoxic effect of deferoxamine.