AnswerCeftriaxone-induced nephrolithiasis and biliary pseudolithiasis. Infrared spectroscopy revealed that the stone was composed of calcium ceftriaxonate.
CommentaryNephrolithiasis in children is principally caused by metabolic factors, obstruction and urinary tract infection. In our case there was no anatomical abnormality of the urinary tract. Urinary tract infection, which was caused by E. coli, had a very favorable clinical course. Appearance of echogenic material in the gallbladder and urinary tract is very suggestive of ceftriaxone (CTX)-induced precipitates. Clinical studies have demonstrated that CTX can induce reversible precipitations in gallbladder with posterior acoustic shadowing, which mimics cholelithiasis [1,2,3,4,5,6]. This complication is termed "biliary pseudolithiasis" or "reversible cholelithiasis". Gallbladder sludge is defined as echogenic material without associated acoustic shadowing. Most patients are asymptomatic, but in a few cases right upper quadrant pain, nausea, vomiting, and even cholecystitis may develop. Clinicians should be aware of these phenomena in order to save patients from unnecessary interventions.Risk factors for CTX-induced gallbladder precipitations are: high-dose CTX therapy (>2 g/day), increased calcium secretion into the bile (hypercalcaemia), decreased bile flow (such fasting or total parenteral nutrition), renal failure and gallbladder stasis after major surgical operations. Although high-dose, long-term CTX therapy is incriminated for this complication, Blais and Duperval reported a case where 48 h of therapy were sufficient for biliary pseudolithiasis to develop [7].There are only a few reports on ceftriaxone-induced nephrolithiasis [1,8,9,10,11]. Among the patients from the original series of Shaad et al, who first reported on CTX-induced biliary pesudolithiasis in 1988 [1], one child was found to have renal colic and obstruction caused by multiple stones. The clinical symptoms were transitory and impairment of renal function resolved after cessation of CTX therapy. Prince and Senac reported a case of both ceftriaxone-induced biliary pseudolithiasis and nephrolithiasis [8]. Their patient presented with acute renal failure due to bilateral ureteral obstruction with calculi, which necessitated placement of ureteral stents. De Moor et al reported a seven-year-old boy who developed biliary pseudolithiasis and nephrolithiasis four days after initiation of treatment with CTX [9]. Avci et al prospectively followed 51 children with various infections who were treated with CTX, and found that 4 (7.8%) developed nephrolithiasis [10]. All stones were small (2 mm) and disappeared spontaneously in three cases. Arcun et al, in their series of 35 children treated with CTX, demonstrated gallbladder precipitation in five children; only one of these had associated urinary bladder sludge [3].Risk factors for CTX-induced urolithiasis are positive familiar history, high CTX dose, rapid infusion rate, dehydration and combination with nephrotoxic drugs [1,8,9,10,11]. Although bilia...