There have been case reports about adverse effects to glucose homeostasis related to gatifloxacin use. The authors report an elderly, non-diabetic patient who developed severe hyperglycemia after receiving oral gatifloxacin 400mg/d. He was a 73-year-old male, patient with a history of hypertension, cured vesical pheochromocytoma, idiopathic dilated cardiomyopathy, chronic renal insufficiency (baseline serum creatinine of 1.7 mg/dL), and gouty arthritis admitted to the hospital with a diagnosis of acute bronchitis. Seven days after initiating gatifloxacin, his symptoms were improved. Subsequently he developed polyuria, polydipsia, and fatigue with an increase in serum creatinine to 2.8 mg/dL, and random plasma glucose levels elevated to 903 mg/dL. Gatifloxacin was stopped. Intravenous regular insulin infusion was administered. Euglycemia was achieved within 8 hours after fluid rehydration and only low dose insulin was required. He maintained normal glucose levels without any antidiabetic drugs afterward. Old age and renal impairment were considered significant contributing factors for this hyperglycemic adverse event from gatifloxacin.

Keywords: Gatifloxacin, Hyperglycemia, Fluoroquinolone, Glucose