Diagnosis of aminoglycoside toxicity often involves monitoring renal function and auditory/vestibular symptoms. Serum creatinine levels are checked regularly to assess kidney function. For ototoxicity, audiometric tests can be performed to detect high-frequency hearing loss early. Clinical symptoms such as tinnitus, imbalance, or vertigo should prompt further investigation. Therapeutic drug monitoring is crucial to ensure plasma concentrations remain within a safe range to minimize toxicity.