Cochlear damage resulting from kanamycin and furosemide

Permanent cochlear damage has been shown to occur in guinea pigs following the combined administration of kanamycin and furosemide. At the doses used, only a transient effect was measured with furosemide alone and no effect was detectable with kanamycin alone. This interaction results when a single subcutaneous dose of 400 mg/kg of kanamycin is followed in 2 hours by a single intravenous dose of furosemide. The dosage range for furosemide was 50 mg/kg for a just-detectable effect to 100 mg/kg for a very severe effect. Damage to the cochlea was ascertained by measures of the a.c. cochlear potential as well as surface preparation histology.