An evaluation of the effects of gatifloxacin on glucose homeostasis

Introduction The United States labeling for gatifloxacin has been updated to include contradictions related to its reported association with dysglycemia. However, adequately controlled studies in acute care settings assessing the magnitude and clinical determinants of dysglycemia are lacking. Objectives To compare the hypoglycemic and hyperglycemic effects of gatifloxacin with ceftriaxone in hospitalized patients. Methods A retrospective cohort study of hospitalized adult (>= 18 years) patients admitted with Community Acquired Pneumonia (CAP) or Acute Exacerbation of Chronic Bronchitis (AECB) in a US tertiary care hospital between 7/1/01 and 12/31/04 treated with gatifloxacin or ceftriaxone during hospital admission. Outcomes of interests were incidence of hypoglycemia (blood glucose levels < 46 mg/dL) or hyperglycemia (> 200 mg/dL) during up to 5 days of drug exposure. Risks for gatifloxacin and ceftriaxone were compared adjusting for variables previously reported to be independent predictors of hypoglycemia or hyperglycemia. Results 1504 patients met the study inclusion criteria. Compared to ceftriaxone, gatifloxacin was associated with an increased risk of hypoglycemia: (adjusted odds ratio (OR) 2.34, 95% confidence interval (CI) 1.4-4.0). The increased risk of hypoglycemia during exposure to gatifloxacin was similar in patients with and without a diagnosis of diabetes mellitus. Gatifloxacin was not associated with an increased risk for hyperglycemia (adjusted OR: 1.06 95% CI 0.8-1.4) considering the whole study cohort. However, stratification by diagnosis of diabetes, gatifloxacin treated patients appeared to have a reduced risk of hyperglycemia (adjusted OR: 0.4 95% CI 0.2-0.4) while non-diabetic gatifloxacin treated patients appeared to have an increased risk of hyperglycemia (adjusted OR: 1.64 95% CI 1.1-2.4). Conclusion The risk of dysglycemia with gatifloxacin in this population of hospitalized patients was not as high as previously reported in ambulatory patients. Although these results suggest gatifloxacin use is safer in acute care settings, we recommend that clinicians monitor blood glucose levels carefully or consider alternatives to gatifloxacin therapy whenever possible.