Hypoglycemia and Hyperglycemia Associated with Gatifloxacin Use in Elderly Patients

W. S. Biggs
2003 Journal of the American Board of Family Medicine  
Fourth-generation quinolones, such as levofloxacin (Levofloxin) and gatifloxacin (Tequin), have become widely used in outpatient and inpatient settings. These quinolones add Gram-positive bacterial coverage and maintain the Gram-negative coverage of earlier quinolones. This broad-spectrum coverage has numerous clinical applications, such as respiratory, gastrointestinal, or urinary systems infections. Because quinolones are equally bioavailable orally or intravenously, they are often used for
more » ... tients at higher risk for serious infection in either outpatient or hospital settings. 1 Gatifloxacin may possess some advantages over other quinolones. In vitro, gatifloxacin is 2 to 4 times more active against Streptococcus pneumoniae than levofloxacin. 2 It also possesses activity against Staphylococcus aureus, some Enterococci, and atypical pathogens, such as Chlamydia pneumoniae and Mycoplasma pneumoniae. 2 In our community hospital with 250 beds, it is the quinolone of choice. Within 2 months in our institution, however, 4 cases of hypoglycemia or hyperglycemia occurred in patients treated with gatifloxacin that either caused hospitalization or lengthened the patients' hospital stay. A literature search revealed no discussion about the potential severity of the hypo/ hyperglycemic side effect; thus, we briefly present these cases. Case Reports Case 1 An 82-year-old man hospitalized for digoxin toxicity had stable serum glucoses on his glipizide (Glucotrol) 5 mg daily. In the hospital, he developed fever. The patient was allergic to penicillin and was started on gatifloxacin (Tequin) based on the empirical evidence. He received 400 mg of gatifloxacin orally and 5 mg of glipizide at 9:00 am. At noon, his capillary blood glucose was 260 mg/dL, and he received 3 units of regular insulin. By 5:00 pm, he was noted to be confused, with a serum glucose of 50 mg/dL. His hypoglycemia persisted despite intravenous glucose (100 g/L) for 12 hours. The patient was eating, and eventually his serum glucose returned to the normal range. The following morning, he again received gatifloxacin and glipizide. By 4:00 pm, he had symptomatic hypoglycemia with a serum glucose of 60 mg/dL. The gatifloxacin and glipizide were discontinued, and the patient's serum glucose increased to the 200 mg/dL level within 24 hours. The glipizide was restarted at 2.5 mg/day, and the patient's serum glucose remained stable until discharge. Case 2 A 68-year-old woman with diabetes taking 1.25 mg/day of glyburide (Micronase) was hospitalized for a congestive heart failure exacerbation. Her urinalysis suggested a urinary tract infection, and the patient began receiving 200 mg/day of oral gatifloxacin. Within 24 hours, the patient developed hypoglycemia. Her capillary blood glucose was between 70 and 80 mg/dL for 2 days despite intravenous glucose and discontinuation of her glyburide. The gatifloxacin was discontinued on the fifth hospital day, and the patient's blood glucose increased to above 200 mg/dL. The glyburide was restarted and the blood glucose levels remained in the 150 to 200 mg/dL range. Case 3 An 82-year-old woman with coronary artery disease and non-insulin-dependent diabetes mellitus who was taking 1000 mg of metformin (Glucophage) twice a day and 10 mg of glipizide (Glucotrol
doi:10.3122/jabfm.16.5.455 fatcat:thvu5twmufdgxpci4lrbebdso4