Aspects of the Chronic Toxicity of Gentamicin Sulfate in Cats

Abstract

For determination of the importance of several factors affecting the vestibular toxicity of gentamicin in cats, several therapeutic regimens, routes of administration, and levels of dosage were examined. Cats were given high levels of gentamicin daily and observed for appearance of ataxia and impairment of the righting reflex. The time of appearance of ataxia was related to dosage. Death, attributed to renal toxicity, closely follows the appearance of ataxia after a dose of 60 mg/kg per day. At lower doses, there is a temporal separation between vestibular and renal toxicity. The renal damage is reversible, but the vestibular damage is not. Total dosage and duration of treatment appear to be more important factors than peak levels of drug in the serum with reference to time of appearance of ataxia at the dosage levels studied.