Guidelines
Side Chain Reference Tool

Side Chain Reference Tool

Penicillin/Cephalosporin Allergy Pharmacy Protocol

Penicillin Ordered

  • Contact prescriber for alternative or desensitization/challenge if PCN is necessary for treatment

Cephalosporin Ordered

  • May use cephalosporin with dissimilar side chain

Penicillin Ordered

  • Contact prescriber for alternative or desensitization/challenge if PCN is necessary for treatment

Cephalosporin Ordered

  • May use cephalosporin

Penicillin Ordered

  • May use penicillin with dissimilar side chain

Cephalosporin Ordered

  • May use cephalosporin with dissimilar side chain

Notes

  • Cefazolin has no like side-chains with any PCN or cephalosporins

  • Cefazolin plus metronidazole (over 30 min) may be substituted for cefoxitin in penicillin allergic (IgE) patients

Antibiotic Side Chain Similarity

  • Ampicillin 6

  • Cefaclor 6/7

  • Cefadroxil 6/7

  • Cefprozil 6/7

  • Cephalexin 6/7

  • Amoxicillin 6

  • Cefaclor 6/7

  • Cefadroxil 6/7

  • Cefprozil 6/7

  • Cephalexin 6/7

  • Amoxicillin 6/7

  • Ampicillin 6/7

  • Cefadroxil 7

  • Cefprozil 7

  • Cephalexin 7

  • Amoxicillin 6/7

  • Ampicillin 6/7

  • Cefaclor 7

  • Cefprozil 7

  • Cephalexin 3,7

  • Cefixime 3

  • Cefotaxime 7

  • Cefpodoxime 7

  • Ceftizoxime 7

  • Ceftriaxone 7

  • Cefdinir 3

  • Cefepime 7

  • Cefpodoxime 7

  • Ceftizoxime 7

  • Ceftriaxone 7

  • No side chain similarities reported

  • Cefuroxime 3

  • Penicillin G 6/7

  • Cefepime 7

  • Cefotaxime 7

  • Ceftizoxime 7

  • Ceftriaxone 7

  • Amoxicillin 6/7

  • Ampicillin 6/7

  • Cefaclor 7

  • Cefadroxil 7

  • Cephalexin 7

  • Ceftizoxime 3

  • Cefepime 7

  • Cefotaxime 7

  • Cefpodoxime 7

  • Ceftibuten 3

  • Ceftriaxone 7

  • Cefepime 7

  • Cefotaxime 7

  • Cefpodoxime 7

  • Ceftizoxime 7

  • Cefoxitin 3

  • Amoxicillin 6/7

  • Ampicillin 6/7

  • Cefaclor 7

  • Cefadroxil 3,7

  • Cefprozil 7

  • Cefoxitin 6/7

Additional Information

J Am Pharm Assoc. 2008;48:530–540.

For international and off-market cephalosporins, refer to full chart in original article