Background: Gatifloxacin is a fluoroquinolone antibiotic that has been associated with severe hypoglycemic and hyperglycemic events.
Objective: The purpose of this report was to describe a new case of gatifloxacin-associated hyperglycemia in an elderly patient and to provide a summary of case reports.
Case summary: A male patient, aged 86 years, was hospitalized with small bowel obstruction due to adhesions from a previous appendectomy. At the time of admission, the patient weighed 78.5 kg (ideal body weight, 73 kg), had a body mass index of 24.8 kg/m2, and had a calculated creatinine clearance of 45.6 mL/min. The patient's hospital medications were metoprolol, diltiazem, subcutaneous heparin, ranitidine, vancomycin, piperacillin/tazobactam, and aspirin. He also was treated with gatifloxacin 400 mg QD for suspected pneumonia during the hospital stay. After 4 days of the gatifloxacin regimen, the patient's mean blood glucose concentration increased from 133 mg/dL at the time of admission to 537 mg/dL. Although the patient exhibited signs of glycosuria (ie, urine glucose concentration >1000 mg/dL), he did not complain of symptoms of hyperglycemia, such as polyuria, polyphagia, or polydipsia. The hyperglycemia resolved after administration of gatifloxacin was discontinued and the patient had received regular insulin 15 U SC over 5 hours.
Discussion: The exact mechanism by which gatifloxacin induces hyperglycemia is unknown, but it may be related to vacuolation of pancreatic beta-cells, leading to a decrease in insulin secretion. This case, along with the 15 other summarized cases, adds to the evidence for an association between gatifloxacin and hyperglycemia. These patients had other risk factors that may have contributed to the development of hyperglycemia, including age >65 years and renal impairment.
Conclusion: An elderly patient with no history of diabetes developed severe hyperglycemia after receiving doses of gatifloxacin 400 mg that had not been adjusted for age-related renal impairment. The hyperglycemia resolved after discontinuation of gatifloxacin.