Interactions : אינטראקציות

4.5       Interaction with other medicinal products and other forms of interaction
Simultaneous administration is Contraindicated
Antibiotics
Cefazolin must not be used together with antibiotics which have a bacteriostatic mode of action (e.g. tetracyclines, sulfonamides, erythromycin, chloramphenicol) since antagonistic effects were observed in in-vitro tests.

Concomitant administration is not recommended
Probenecid
The renal clearance of cefazolin is reduced when probenecid is co-administered.

Precautions
Vitamin K1
Some cephalosporins such as cefamandol, cefazolin and cefotetan may interfere with the metabolism of vitamin K1, especially in cases of vitamin K1 deficiency. This may require vitamin K1 supplementation.

Anticoagulants
Cephalosporins may very rarely lead to blood coagulation disorders (see section 4.4). If oral anticoagulants or high dosage heparin are concomitantly used, coagulation parameters should be monitored.

Nephrotoxic agents
An increase in nephrotoxic effects of antibiotics (e.g. aminoglycosides, colistin, polymyxin B) and diuretics (e.g. furosemide) cannot be ruled out. Renal values should be carefully monitored when these medicinal products are co-administered with cefazolin.

Laboratory tests
Laboratory tests for urinary glucose concentrations may give false positive readings if based on Benedict's solution, Fehling's solution or Clinitest® tablets. However, cefazolin does not affect enzyme-based tests.
Both the indirect and the direct Coombs test may also give false positive readings, e.g. in newborns whose mothers received cephalosporins.