effect on blood sugar level count?

I have diabetes for which I take a daily dosage of 2mg Glimepiride; doctor prescribed Azithromycin for bronchial problem. Have taken first double dosage at 9:00 P.M. last evening, and single dosage at 8:00 A.M. this morning (3 more single doses to follow). Blood sugar level test taken at 9:00 P.M. this evening revealed bloodsugar level count rose from an average of low 100's to 312. Is this a normal reaction to this medication, and should I be concerned??