Drug‐induced crystalluria attributable to tosufloxacin in children

BackgroundDrug-induced crystalluria is reportedly caused by a large number of drugs. Tosufloxacin (TFLX), a second-generation fluoroquinolone antibiotic, is reported to cause kidney injury and crystalluria. We retrospectively analyzed patients with crystalluria caused by TFLX to clarify the clinical course of TFLX-induced crystalluria in children. MethodsThis study was designed as a retrospective case series using the database of the National Center for Global Medicine covering the period from January 1, 2020 to March 31, 2021. We enrolled pediatric patients aged 15 years or younger with crystalluria attributable to TFLX treated in our pediatric department and collected clinical data. ResultsThirteen patients were diagnosed with crystalluria attributable to TFLX. The median age of the patients at diagnosis was 4.0 years (range, 0.8-15 years; interquartile range = 1.2-8.8 years), and five patients (38%) were male. Six patients (46%) had gastrointestinal symptoms such as vomiting and abdominal pain, and 12 patients (92%) had decreased oral intake. The median time to diagnosis after TFLX administration was 4 days (range, 2-7 days; interquartile range = 3-6 days). All patients received TFLX at the appropriate dose. Two patients (17%) were diagnosed with acute kidney injury, and both had gastrointestinal symptoms such as vomiting and abdominal pain. ConclusionsCrystalluria induced by TFLX occurred despite administration of the appropriate dose of TFLX. Physicians should recognize crystalluria and renal injury attributable to TFLX. It may be possible to prevent renal injury by discontinuing drug therapy.