シタグリプチン過量服薬の1例(A case of sitagliptin overdose)

要旨 シタグリプチンは，dipeptidyl peptidase–4（以下DPP–4）阻害剤で，わが国では，2009年に2型糖尿病に対し製造販売承認を取得した新しい作用機序の経口糖尿病治療薬である。他の経口糖尿病治療薬に比し低血糖を来しにくく，現在幅広く使用されている。今回，シタグリプチンを過量服薬した1例を経験したので報告する。症例は60歳代の男性，母親と口論になり発作的にシタグリプチンを700mg内服し，全身倦怠感を呈して救急外来を受診した。簡易血糖は293mg/dLであり，輸液のみで入院となった。入院後，2時間ごとに簡易血糖を測定したが低血糖は出現しなかった。第2病日も低血糖を認めず，症状が軽快したため退院となった。シタグリプチン血中濃度は内服3.5時間後2.34mg/L，11.5時間後0.446mg/L，21.5時間後0.323mg/Lであった。過去の研究と照合し，本症例は12時間以内に最高血中濃度があったと推測され，その間に血糖低下を認めず，シタグリプチン血中濃度と血糖値の間に相関もなかった。したがって，腎機能が正常であれば，シタグリプチン過量服薬により，低血糖を生じるリスクは低い可能性があるが，今後さらなる評価を要する。 ABSTRACT The dipeptidyl peptidase–4 (DPP–4) inhibitor, sitagliptin has been approved for manufacturing and distribution in Japan in 2009 as a new class of oral hypoglycemic agent for management of diabetes. At present, sitagliptin is usually administered at daytime because patients do not suffer from hypoglycemia after intake. In this case, we encountered a man with type 2 diabetes in his 60s who deliberately and compulsively ingested of 700mg of sitagliptin after an exchange of words with his mother. Afterwards, he visited the emergency room because of a sense of fatigue. His plasma glucose was 293mg/dL. He was admitted to the hospital and received intravenous fluids. Blood glucose monitoring every 2hr did not show any episodes of hypoglycemia. On the 2nd day of hospitalization, he did not show any episodes of hypoglycemia, and got less severe; he was subsequently discharged on the same day. Plasma concentration of sitagliptin at 3.5hr, 11.5hr, and 21.5hr after were 2.34mg/L, 0.446mg/L, and 0.323mg/L, respectively. Considering past studies, it is inferred, plasma concentration of sitagliptin was maximum no later than 12hr, and patients didn’t suffer from hypoglycemia. Patients who overdose on sitagliptin are at low risk for hypoglycemia if their renal function is normal.