Study objectives: To assess the prevalence of dysglycemia (hypoglycemia or hyperglycemia) associated with oral levofloxacin and gatifloxacin therapy in an outpatient setting, and to determine the characteristics of patients who developed dysglycemia while receiving either fluoroquinolone.
Design: Retrospective medical record review.
Setting: Outpatient clinic of a Veterans Affairs teaching hospital.
Patients: A total of 1573 patients who received oral levofloxacin (343 patients), gatifloxacin (589 patients), or azithromycin (as a control, 641 patients) between June 1, 2004, and May 31, 2006.
Measurements and main results: Dysglycemia occurred in 33 patients: 13 (2.2%), 9 (2.6%), and 11 (1.7%), respectively, of those in the gatifloxacin, levofloxacin, and azithromycin groups. Of 13 patients who experienced a hyperglycemic event, 11 (84.6%) had diabetes mellitus. After adjustment for confounding factors, neither levofloxacin nor gatifloxacin were associated with increased odds of developing a dysglycemic event compared with azithromycin. Multivariate analysis demonstrated that lack of downward dosage adjustment based on creatinine clearance (odds ratio [OR] 10.3, 95% confidence interval [CI] 3.8-27.6), presence of diabetes (OR 17.1, 95% CI 3.1-94.9), or treatment with insulin (OR 5.3, 95% CI 1.8-15.7) or sulfonylureas (OR 3.6, 95% CI 1.3-10.4) independently increased dysglycemia risk. Obesity (body mass index > or = 30 kg/m(2)) was independently protective (OR 0.22, 95% CI 0.09-0.55) against dysglycemic events.
Conclusion: Levofloxacin and gatifloxacin were not significantly associated with increased dysglycemic events compared with azithromycin. Lack of downward fluoroquinolone dosage adjustment for renal function, presence of diabetes, and treatment with insulin or sulfonylureas each independently increased the risk of dysglycemia. Obesity was independently protective against dysglycemia. More data are needed on the contributing effects of diabetes, fluoroquinolone dosage, and concomitant drug therapy so that an appropriate risk-management strategy can be developed.