Cefazolin.
After 5 years of use, cefazolin can be considered similar to cephalothin as a therapeutic agent and in its potential for adverse reactions. When cefazolin and cephalothin are compared by appropriately designed clinical trials, neither cefazolin's slightly greater in-vitro susceptibility to staphylococcal beta-lactamase inactivation, nor its slightly greater microbiologic activity for some enterobacteraciae has been shown to result in any readily apparent therapeutic differences. The important differences between cefazolin and cephalothin--and this is also probably true with respect to cephapirin and cephradine--are not in therapeutic effectiveness, microbiologic activity, or toxicity but rather in pharmacokinetics and cost-effectiveness.
D000380:Agranulocytosis / Q000188:drug therapy; D001424:Bacterial Infections / Q000517:prevention & control; D002437:Cefazolin / Q000009:adverse effects / Q000494:pharmacology / Q000627:therapeutic use; D002511:Cephalosporins / Q000627:therapeutic use; D002512:Cephalothin / Q000494:pharmacology; D002986:Clinical Trials as Topic; D004342:Drug Hypersensitivity; D006801:Humans; D011014:Pneumonia / Q000188:drug therapy
D002511:Cephalosporins; D002437:Cefazolin; D002512:Cephalothin