Gentamicin-induced ototoxicity and nephrotoxicity vary with circadian time of treatment and entail separate mechanisms.

The aminoglycoside antibiotic gentamicin can cause both ototoxicity and nephrotoxicity, the severity of which varies with circadian time of daily treatment. However, it is not yet resolved if such drug-induced adverse effects are independent or interdependent phenomena. Two groups of 9 female Sprague-Dawley rats (200-250 g), each housed separately and entrained to a 12 h light (06:00-18:00 h) - 12 h dark cycle, received a daily subcutaneous injection of 100 mg/kg gentamicin.

Circadian variation of gentamicin toxicity in rats.

Objectives/hypothesis: Two undesired effects of the aminoglycoside antibiotic gentamicin are ototoxicity and nephrotoxicity. This study investigated if these adverse effects vary according to the circadian time of its administration.

Study Design: This study entails laboratory animal research.