The effect of picibanil (OK-432) on middle EAR and cochlea

Interest in intratympanic treatment of inner ear diseases has increased significantly in the last two decades. The systemic side effects of the drugs will be avoided with intratympanic treatments, but should be careful of ototoxicity which can be seen with local administration of these drugs. Picibanil (OK-432) is used clinically in malign diseases systemically or locally as an adjuvant treatment agent and for sclerosing effect in lymphatic malformations and cystic lesions. Although there have been many studies on the use of OK-432 in literature, there has been no study in the English literature about the effects on the middle ear and cochlea. In this study, histopathological effects and ototoxicity of OK-432 with local use on the ear were investigated. In the study, 40 guinea pigs were randomly selected and divided into eight groups of five. There are four study and four control groups. In the study groups, the subjects were performed intratympanic OK-432 (1 KE 0,1 ml) injections at two groups of one injection and other two groups of three injections. One and three injections groups were sacrificed one week later and the other one month later. The control groups were performed of saline injection with the same doses, duration and frequency, similarly to the study groups. The effects of OK-432 were evaluated by electrophysiological tests and histopathological findings. The study groups were compared with the control groups and themselves. In our study, intratympanic use of OK-432 did not show any significant change in the middle ear in the short term, but microscopic degeneration was detected on the cochlea. Electrophysiological tests showed early signs of hearing loss and ototoxic effects. Our study can guide studies on the use of OK-432, which is also available locally, as an intratympanic treatment agent in some middle ear and inner ear diseases for a variety of indications.