Asymptomatic ceftriaxone-associated pseudolithiasis.

An 88-year-old woman with a history of meningioma and dementia was admitted with high fever, loss of appetite, and nausea in July. Urinary tract infection was suspected. Computed tomography (CT) showed no significant findings. Urinary findings improved with administration of ceftriaxone. However, high fever appeared on hospital day 28, and CT identified a gallbladder stone without any abdominal symptoms. We considered the possibility of ceftriaxone-associated pseudolithiasis and changed pharmacotherapy to cefmetazole. CT on day 34 showed a reduction in the size of the gallbladder stone. Ceftriaxone-associated pseudolithiasis might arise in the absence of abdominal symptoms, and clinicians should take the patient background and season into account when using this agent.