RESUMO
PURPOSE: Ceftriaxone, a parenteral third-generation cephalosporine, is widely used in the treatment of various bacterial infections. It possesses high calcium-binding affinity, forming complexes with calcium in bile salts to develop precipitate that mimics gallstone on ultrasonography. Biliary pseudolithiasis resolves completely with cessation of therapy, but several symptomatic patients have undergone cholesystectomy. We prospectively evaluated the incidence, risk factors and dose- related comparison with ultrasonography. METHODS: Between November 1998 and August 1999, 81 cases of inpatients on ceftriaxone treatment in Dongguk University Pohang Hospital were enrolled for this study. They were divided according to dose of ceftriaxone, high-dose and low-dose groups. Repeated sonography was performed on 1, 3, 5 and 7 days after initiation of ceftriaxone treatrnent and then weekly until pseudolithiasis were resolved. RESULTS: Thirty-eight percent of the subjects acquired pseudolithiasis. Sonographic abnormalities appeared from 1 to 10 days after ceftriaxone therapy and completely resolved from 1 to 24 days after cessation of ceftriaxone therapy. The incidence of pseudolithiasis was significantly higher in the high-dose group(P<0.001). In the high-dose group, fasting over a day was a significant risk factor of pseudolithiasis(P<0.01). Sex, age, duration of ceftriaxone therapy, laboratory findings, type of infection or chief complaint were not significant risk factors for pseudolithiasis. CONCLUSION: We suggest that abdominal ultrasonography should be considered in all children who receive high dose ceftriaxone with fasting over a day. If pseudolithiasis was developed, we can detect the most of resolution after 30 days of cessation of therapy.