Suggest Treatment For Fluctuating Sugar Levels Based On The Intake Of Levofloxacin

I take januvia a day when I take Levofloxacin 500mg a day my sugar go down good before meal 109 after meal 137 but when I stop take levofloxacin sugar up before Ml 142 after meal 230 I still take Januvia 100mg a day . Please! Tell me what to do for sugar go down normal