Comparative vestibular toxicity of dibekacin, habekacin and cisplatin

The vestibular toxicity of two aminoglycoside antibiotics, dibekacin sulfate and habekacin sulfate, and of a drug with potent antimitotic activity, cisplatin (cis-diamminedichloroplatinum) has been investigated in both rats and frogs. In rats, chronic intraperitoneal injection of a saline solution of dibekacin (50 mg/kg/day), habekacin (50 mg/kg/day), cisplatin (0.5 mg/kg/day) for 4 weeks and of cisplatin (1 mg/kg/day) for 5 weeks, produced no behavioral vestibular disorders and the righting reflex could be elicited at any time. In frogs, the spontaneous discharge was recorded from individual fibres of the ampullary nerve of the horizontal semicircular canal before and after acute administration of the drugs, dissolved in Ringer, into the perilymph of the inner ear near the horizontal ampulla. Following injection of 1 microliter of solutions containing 10 micrograms or 20 micrograms of dibekacin, 20 micrograms or 50 micrograms of habekacin, 0.5 micrograms, 2.5 micrograms or 10 micrograms of cisplatin, the spontaneous discharge decreased in a number of fibres and was sometimes completely abolished. The vestibular toxicity of the three drugs tested is discussed with respect to that of aminosides whose ototoxicity is well known.