Reduced blood glucose levels by the combination of vadadustat in an elderly patient with chronic kidney disease who was receiving mitiglinide and sitagliptin: a case report

Abstract

Abstract Background Our case is the first report showing the development of hypoglycemia following the administration of vadadustat in a patient with chronic kidney disease being treated with mitiglinide and sitagliptin, possibly due to drug–drug interaction between vadadustat and sitagliptin under the administration of mitiglinide. Case presentation A 72-year-old man with type 2 diabetes mellitus had received sitagliptin 50 mg once daily and mitiglinide 10 mg three times daily over the last 3 years. He initiated vadadustat 300 mg once daily orally on day X owing to renal anemia (hemoglobin A1c: 7.4% and estimated glomerular filtration rate: 28.0 mL/min/1.73 m2). On day 23, he developed hypoglycemia with a blood glucose level of 67 mg/dL. The mean blood glucose level ± standard deviation was lower in the first 24 days of co-administration of vadadustat (before breakfast: 94 ± 14 mg/dL, before lunch: 109 ± 24 mg/dL, and before dinner: 126 ± 39 mg/dL) than in the last 2 weeks (before breakfast: 108 ± 14 mg/dL, before lunch: 122 ± 24 mg/dL, and before dinner: 158 ± 39 mg/dL). Considering the timing of the concomitant administration of vadadustat, hypoglycemia may have been caused by the drug–drug interaction between sitagliptin and vadadustat, and he discontinued treatment with vadadustat. The mean blood glucose levels improved two weeks after the discontinuation of vadadustat (before breakfast: 121 ± 25 mg/dL, before lunch: 147 ± 38 mg/dL, and before dinner: 161 ± 36 mg/dL). The drug interaction probability scale was classified as "Probable" (5 points). Conclusions Hypoglycemia was observed when sitagliptin, mitiglinide, and vadadustat were concomitantly administered, which may have resulted in a drug–drug interaction between vadadustat and sitagliptin via OAT3 inhibition in the renal tubules.