Xtenda Drug Interactions

Probenecid: Concomitant administration of oral Probenecid (500 mg daily) does not appear to effect the pharmacokinetics of ceftriaxone, presumably because ceftriaxone is excreted principally by glomerular filtration and non renal mechanism. However higher dosage of oral probenecid (1 or 2 gm daily) administered concomitantly reported may partially block biliary secretion of ceftriaxone as well as displace the drug from plasma proteins. As a result, serum clearance of ceftriaxone may be decreased by about 20%.
Aminoglycosides: In vitro studies indicate that the antibacterial activity of ceftriaxone and aminoglycosides (amikacin, gentamicin, tobramycin) may be additive or synergistic against some strains of Enterobacteriaceae and some strains of Pseudomonas aeruginosa. Although the clinical importance has not been determined to date.
Antagonism has also occurred rarely in vitro when ceftriaxone was used in combination with an aminoglycoside. Organisms with high level resistance to both the aminoglycoside and the beta-lactam antibiotic alone are unlikely to be synergistically inhibited by concomitant use of drugs.
Quinolones: Although the clinical importance is unclear, results of an in vitro study indicate that the combination of ceftriaxone and trovafloxacin is synergistic against both penicillin-susceptible and penicillin-resistant Streptococcus pneumoniae, including some strains that also were resistant to ceftriaxone alone. There was no evidence of antagonism with the combination of ceftriaxone and trovafloxacin.
Alcohol: A disulfiram like reaction reportedly occurred in one patient who ingested alcohol while receiving ceftriaxone; however this effect generally has been reported only with beta-lactam antibiotics that contain an N-methylthiotetrazole (NMTT) side chain (e.g. cefamandole, cefoperazone, cefotetan).
Laboratory Value Alterations: Although transient elevations of BUN and serum creatinine have been observed, at the recommended dosages the nephrotoxic potential of Ceftriaxone is similar to that of other cephalosporins.
Alternations in prothrombin times have occurred rarely in patients treated with Ceftriaxone. Patients with impaired vitamin K synthesis or low vitamin K stores (eg. Chronic hepatic disease and malnutrition) may require monitoring of prothrombin time during Ceftriaxone treatment. Vitamin K administration (10 mg weekly) may be necessary if the prothrombin time is prolonged before or during therapy.
There have been reports of sonographic abnormalities in the gall bladder of patients treated with Ceftriaxone; some of these patients also had symptoms of gall bladder disease. These abnormalities appear on sonography as an echo without acoustical shadowing suggesting sluge or as an echo with acoustical shadowing which may be misinterpreted as gallstones. The chemical nature of the sonographically detected material has been determined to be predominantly a ceftriaxone-calcium salt. The condition appears to be transient and reversible upon discontinuation of ceftriaxone and institution of conservative management. Therefore, ceftriaxone should be discontinued in patients who develop signs and symptoms suggestive of gallbladder disease and/or the sonographic findings described previously.