Figure 1. Clinical course. On December 20, 2010, the patient was administered an oral antibiotic, cefcapene pivoxil hydrochloride (CFPN-PI) 100 mg 3 times a day for 1 week. One week later, he was switched to clarithromycin (CAM) 200 mg/day for 3 weeks (arrow). His glycosylated hemoglobin (HbA1c, NGSP) level deteriorated from 7.0% on November 19, 2010, to 10.6% on January 14, 2011. Subcutaneous administration of insulin aspart was initiated at a dose of 5 units before every meal on January 28, 2011. Thereafter, his HbA1c level was markedly improved. The dose of insulin was decreased and the oral hypoglycemic agents (metformin 500 mg/day and sitagliptin 25 mg/day) were administered. In August 2012, his HbA1c level was 6.3% without insulin and metformin. No deterioration in glycemic control was observed at the 2-year follow-up visit.