Risk factors of ceftriaxone-associated biliary pseudolithiasis in adults: influence of renal dysfunction

Ceftriaxone (CTRX) is a known cause of biliary pseudolithiasis (BPL) mainly in children. Biliary elimination of CTRX increases in patients with renal dysfunction. However, the influence of renal dysfunction on the incidence of CTRX-associated BPL has not been well investigated. The aim of this study was to investigate the cumulative incidence of CTRX-associated BPL in adults and to assess if renal dysfunction is a risk factor. We retrospectively analyzed the medical records of 478 patients treated with CTRX to assess the incidence and risk factors of CTRX-associated BPL. We examined age, sex, body weight, dosage, and duration of CTRX therapy, and the concentrations of serum creatinine, estimated glomerular filtration rate (eGFR), albumin, and serum calcium in all the patients. The cumulative incidence of BPL was calculated using a competing risk model. The multivariate analysis of each variable for the development of BPL was assessed by a Cox proportional hazards model. A total of 362 patients (75.7%) had renal dysfunction (eGFR: < 60 mL/min). The cumulative incidence of BPL in patients with renal dysfunction was significantly higher than that in patients with normal kidney function (4.1 vs. 0.6%, p = 0.017). Renal dysfunction (Hazard ratio (HR) 8.14, 95% CI 1.05-63.0, p = 0.045) and female sex (HR 5.35, 95% CI 1.17-24.5, p = 0.031) were independent risk factors of CTRX-associated BPL, which was confirmed using multivariate analysis (renal dysfunction: HR 7.93, 95% CI 1.04-60.5, p = 0.046) (female sex HR 4.65, 95% CI 1.03-21.1, p = 0.046). Renal dysfunction is an independent risk factor of CTRX-associated BPL in adults.