Gatifloxacin can affect blood glucose more than other quinolones.
Package inserts for all of the quinolones list high and low blood sugar as possible side effects in diabetic patients. These problems seem more likely with gatifloxacin than other quinolones.
The FDA reports 477 cases of blood sugar problems in 10 million prescriptions for gatifloxacin. This is more than all the blood sugar problems for ciprofloxacin, levofloxacin, and moxifloxacin combined.
The use of gatifloxacin is now contraindicated in Japan in patients with diabetes.