ceftriaxone ( ctrx ) is a broad - spectrum third - generation cephalosporin antibiotic with favorable tissue absorption . because of its long half - time in plasma and metabolism via both renal and hepatic excretion , ctrx is widely used to treat bacterial infectious diseases not only in patients without any underlying disease , but also in patients with renal disease [ 1 , 2 ] . biliary pseudolithiasis is a known ctrx - associated adverse event [ 3 , 4 ] . it has been proposed that high doses of ctrx are excreted into the bile , where excreted ctrx then binds with calcium . the ctrx - calcium complexes then precipitate as biliary pseudolithiasis , and these stones may finally lead to the development of ctrx - induced pseudolithiasis . reported risk factors for ctrx - induced pseudolithiasis include pediatric age , high - dose or long - term ctrx treatment , hypercalcemia , fasting , total parenteral nutrition , renal failure , and previous history of major surgery [ 5 , 6 , 7 , 8 , 9 ] . however , there have been no reports regarding ctrx - induced pseudolithiasis in adult patients receiving maintenance hemodialysis . here we describe a case of ctrx - induced pseudolithiasis in an adult patient receiving maintenance hemodialysis that resolved following ctrx cessation . a 79-year - old japanese woman ( height , 135.0 cm ; weight , 29.9 kg ) having received maintenance hemodialysis for 6 years due to end - stage renal disease ( esrd ) as a result of antineutrophil cytoplasmic antibody - associated glomerulonephritis was referred to our hospital because of a fever of 37.7c , cough , and general fatigue . a blood analysis at presentation revealed a white blood cell ( wbc ) count of 6,500/l and a c - reactive protein ( crp ) level of 10.8 mg / dl with hepatic and biliary enzymes within normal limits . inflammatory infiltrates were detected in the middle and right lower lung fields by plain chest radiography . computed tomography ( ct ) scans revealed ground - glass opacification throughout the middle and right lower lung fields . she was diagnosed with bronchial pneumonia , and 1 g of ctrx on alternating days was initiated intravenously following hemodialysis in consideration of its nondialyzability . the cough , fever , general fatigue , and laboratory data steadily improved following ctrx administration . the wbc count was 5,300/l and the crp level was 1.4 mg / dl on the 11th day after ctrx initiation . however , on the 13th day , she unexpectedly presented with stomachache around the right hypochondrium with a firm , round mass and a slight fever of 37.2c . the wbc count was 10,560/l , the crp level was 8.8 mg / dl , and hepatic and biliary enzymes were within normal limits . to determine the source of her stomachache and slight fever , immediate imaging studies were performed . ct scans revealed improvement of her pneumonia ; however , one gallstone ( 16  9 mm ) was revealed in the gallbladder with thickening of the gallbladder wall that was not detected on the previous cts ( fig . therefore , ctrx - induced gallbladder pseudolithiasis was suspected , and ctrx was immediately discontinued . although her stomachache had completely resolved 4 days after ctrx cessation , follow - up cts demonstrated no significant change in the gallstone or gallbladder wall thickness at day 5 following ctrx cessation . twelve days following ctrx withdrawal , the gallstone and increased gallbladder wall thickness gradually improved . the patient survived disease free for 5 months after disappearance of the gallstone without any symptoms of cholelithiasis or cholecystitis . ctrx is cleared by both renal and hepatic excretion , meaning that ctrx has become a standard option in patients with renal disease , including hemodialytic patients [ 1 , 2 , 10 ] . in general , ctrx is relatively safe and effective ; however , it occasionally causes adverse events . biliary pseudolithiasis is one of the ctrx - associated adverse events [ 3 , 4 ] . to the best of our knowledge , this is the first report of ctrx - induced pseudolithiasis in an adult patient receiving maintenance hemodialysis . the first report of ctrx - induced biliary pseudolithiasis was in a population of pediatric patients . since then , there have been many reports of ctrx - induced pseudolithiasis , although these reports have mainly been on pediatric patients and rarely on adults . by utilizing ultrasound examinations , heim - duthoy et al .   revealed that the incidence of ctrx - induced pseudolithiasis in adult patients is approximately 20% ; however , only 30% of these 20% presented with clinical symptoms . these reports indicate that physicians are unable to detect asymptomatic ctrx - induced pseudolithiasis ; nevertheless , this is rarely a clinical issue , since most cases of symptomatic and asymptomatic pseudolithiasis in these patients resolve spontaneously following ctrx withdrawal . there have been many other reports suggesting that ctrx - induced pseudolithiasis is reversible with discontinuation of ctrx . abnormal gallbladder sonograms were found 322 days ( mean , 9 days ) following ctrx initiation . the period between abnormal sonograms and returning to normal was 263 days ( mean , 15 days ) from ctrx cessation . thus , ctrx - induced pseudolithiasis is not very rare ; however , there have been few reports regarding ctrx - induced pseudolithiasis in adult patients . this is particularly true for patients with esrd , as there is only one report of an adult peritoneal dialysis patient . it has been proposed that the formation of a ctrx - calcium complex is key to the development of biliary pseudolithiasis . although approximately 3070% of ctrx is eliminated unchanged via renal excretion , the remainder is excreted into bile . the concentration of ctrx in the gallbladder can reach levels 20150 times higher than in serum . these high concentrations of ctrx may bind with calcium cations in bile , similar to bilirubin . afterward , the precipitated sludge forms stones and may finally develop into ctrx - induced pseudolithiasis . on the basis of these mechanisms , proposed risk factors of ctrx - induced pseudolithiasis include : ( 1 ) hypercalcemia , which increases calcium secretion in the bile ; ( 2 ) fasting , dehydration , and total parenteral nutrition , decreasing bile flow ; ( 3 ) pediatric age , renal failure , or high - dose and long - term treatment , increasing the proportion of ctrx excretion into bile , and ( 4 ) a previous history of major surgery , which may cause gallbladder stasis [ 5 , 6 , 7 , 8 , 9 ] . biner et al .   prospectively analyzed 156 children treated with varying ctrx doses ( 50 , 75 , and 100 mg / kg / day ) and reported that independent risk factors for ctrx - induced biliary pseudolithiasis were age and higher ctrx dosages . the incidence of ctrx - induced biliary pseudolithiasis reached around 33% in patients receiving 100 mg / kg / day of ctrx and 11% in patients receiving 50 mg / kg / day . on the other hand , our patient developed biliary pseudolithiasis despite receiving only 16 mg / kg / day of ctrx . consequently , ctrx could not be metabolized or excreted by the kidney , but only by the liver . therefore , even very small doses of ctrx were able to increase gallbladder concentrations , potentially leading to the development of ctrx - induced biliary pseudo - lithiasis . as described above , liver - excreted ctrx binds with calcium in bile , and the formation of ctrx - calcium complexes may lead to ctrx - induced pseudolithiasis . patients on maintenance hemodialysis occasionally receive alfacalcidol and a calcium - based phosphate binder to prevent secondary hyperparathyroidism , and these patients consequently tend to develop hypercalcemia . in our case , the patient was being treated with 0.25 g / day of alfacalcidol , but not calcium carbonate or bisphosphonate . her albumin - adjusted serum calcium levels on admission were approximately 9.59.9 mg / dl , and the serum whole parathyroid hormone level was approximately 1320 pg / ml . the ability of vitamin d and whole parathyroid hormone to increase calcium secretion into bile is controversial ; however , patients receiving hemodialysis , and especially those receiving vitamin d or calcium - based phosphate binders , may be at higher risk of ctrx - induced pseudolithiasis . furthermore , udp glucuronosyltransferase 1a1 ( ugt1a1 ) gene polymorphisms also have been proposed as a possible risk factor for ctrx - induced pseudolithiasis . in our case , we did not check whether the patient possessed these gene polymorphisms ; however , the evaluation of such a genetic risk before using ctrx would be very useful to protect patients from this adverse event . we described a case of ctrx - induced pseudolithiasis in an esrd patient receiving maintenance hemodialysis .
ceftriaxone ( ctrx ) is a third - generation cephalosporin widely used for the treatment of bacterial infections in patients with renal disease because of its excretion by both renal and hepatic mechanisms . 
 biliary pseudolithiasis is a known ctrx - associated complication ; however , there have been no studies of this adverse event in adult patients receiving maintenance hemodialysis . 
 here we report the case of a 79-year - old japanese woman with end - stage renal disease ( esrd ) receiving maintenance hemodialysis who developed ctrx - induced pseudolithiasis . 
 the patient received ctrx for bronchial pneumonia . 
 fifteen days following ctrx initiation , the patient presented with stomachache . because of the presence of one gallstone and increased gallbladder wall thickness on computed tomography scans , not detected at the onset of pneumonia , the patient was diagnosed with ctrx - induced gallbladder pseudolithiasis . 
 ctrx was discontinued immediately . at 48 days following ctrx withdrawal , 
 the gallstone and thickening of the gallbladder wall had completely resolved . 
 esrd may be a risk factor for ctrx - induced pseudolithiasis as hepatic excretion of ctrx is the predominant clearance mechanism in patients with esrd . more attention 
 should be paid to ctrx - induced pseudolithiasis following the use of ctrx in esrd patients .