Abstract
Biliary pseudolithiasis is a ceftriaxone (CTRX)-induced complication, but the risk in cases of elderly type 1 diabetes mellitus (T1DM) is unclear. Case 1: A 78-year-old woman with T1DM complicated by diabetic autonomic neuropathy was admitted with pneumonia and treated with CTRX. On day 8, biliary pseudolithiasis and cholecystitis were observed. Case 2: an 80-year-old woman with T1DM was suspected of having a urinary tract infection and treated with CTRX. After a week, she developed asymptomatic biliary pseudolithiasis with gastroparesis. CTRX-associated biliary pseudolithiasis was thus noted in these cases of elderly T1DM. CTRX should be cautiously administered, especially in elderly T1DM patients with diabetic autonomic neuropathy.