Abstract
Ototopical solution with some kinds of antibiotics induced sensorineural deafness, if it was administered to the middle ear for long duration. By the above reason, it is important examination toclarify the ototoxicity of new developing ototopical solution of CMX (cefmenoxime) before clinical application. 31 animals of Hartley strained guinea pigs were used in this study. In 28 animals, after performing of artificial perforation at each ear drum, eachleft sided middle ear cavity was received 1% CMX ototopical solution 0.2 ml for 5 days. Three animals were received 1% CMX through the minute tubes which were touched with left middle ear cavity. Other right sided ear cavities were received 0.5% CP ototopical solution in 6 animals, 0.3% GM in 5 animals and2.0% KM in 5 animals. Among the remained animals, right cochleae of 8 animals were destroyed by surgery for the purpose of unilateral ABR recording. After performing of artificial perforation, right middle ear cavities of 4 animals were observed without administration of drug, and 3 animals of control group were not received any treatment. Afterfinishing the above procedure, each animal wasfixed by the method of intravitalfixation with 10% neutral formalin solution for pathohistological examination. The microscopic observation was focused the damage of Corti's organ, especially degeneration of the hair cells. As the results of the above experimental procedure, no remarkable changes of Corti's organ were present in 31 ears, which were received CMX. Degeneration of outer hair cells at lower part of basal turn was appeared in only one animals of KM receiving animals.
