Carbamazepine: Elevated carbamazepine levels have been reported in postmarketing experience when Cefixime was administered concomitantly.
Drug monitoring may be of assistance in detecting alterations in carbamazepine plasma concentrations.
Warfarin and anticoagulants: Increased Prothrombin Time, with or without clinical bleeding, has been reported when Cefixime was administered concomitantly.
Care should therefore be taken in patients receiving anticoagulation therapy.
Probenecid: Concomitant administration of Probenecid increases peak serum concentrations and the AUC while decreasing the renal clearance and volume of distribution of Cefixime.
Other drugs: Concomitant administration of Cefixime and Nifedipine increases the oral bioavailability of Cefixime as a result of higher peak plasma concentrations and area under the plasma concentration time curve.
In vitro, in pooled serum, Acetaminophen, Heparin, Phenytoin, Diazepam, Ibuprofen or Furosemide had no clinically important effects on the protein binding of Cefixime.
Laboratory test interferences: Tests for urinary glucose: Cefixime, like most Cephalosporins may cause false positive results in urinary glucose determinations, using cupric sulphate as in Benedict's solution, Clinitest or Fehling's slolution, but enzymatic Glucose Oxidase methods are unaffected.
Immunohematology tests: A false positive direct Coombs test has been reported during treatment with Cephalosporin antibiotics, therefore it should be recognised that this reaction may interfere with hematologic studies or transfusion cross matching procedures and should be considered in patients receiving Cefixime.
Urinary ketones: Cefixime may cause false positive results for urinary ketones when tests using nitroprusside are used but not with tests using nitroferricyanide.
FC tab: General: A false positive reaction for glucose in the urine may occur with Benedict's or Fehling's solutions or with copper sulphate test tablets, but not with tests based on enzymatic glucose oxidase reactions.
A false positive direct Coombs test has been reported during treatment with cephalosporin antibiotics, therefore it should be recognized that a positive Coombs test may be due to the drug.
In common with other cephalosporins, increases in prothrombin times have been noted in a few patients. Care should therefore be taken in patients receiving anticoagulation therapy.