From the Guidelines
Cefdinir is highly unlikely to be associated with cross-reactivity in patients with penicillin allergies, with a cross-reactivity rate ranging from 2.0% to 4.8%. For patients with a history of mild penicillin allergy, cefdinir can typically be used safely as the cross-reactivity rate is approximately 1-2% 1. However, patients with severe penicillin allergies, such as anaphylaxis, angioedema, or Stevens-Johnson syndrome, should exercise caution when using cefdinir due to a potentially higher cross-reactivity risk.
Key Considerations
- The chemical structure of the cephalosporin determines the risk of cross-reactivity between specific agents, with second- and third-generation cephalosporins like cefdinir having a lower risk of cross-reactivity compared to first-generation cephalosporins 1.
- A study analyzing pooled data of 23 studies, including 2400 patients with reported history of penicillin allergy and 39,000 with no penicillin allergic history, concluded that many patients who present with a history of penicillin allergy do not have an immunologic reaction to penicillin 1.
- The Joint Task Force on Practice Parameters recommends a cephalosporin in cases without severe and/or recent penicillin allergy reaction history when skin test is not available 1.
Recommendations
- For patients with severe penicillin allergies requiring cefdinir, desensitization protocols or alternative non-beta-lactam antibiotics may be more appropriate options 1.
- Consider the severity of the previous reaction, the generation of the cephalosporin, and potentially consult with an allergist when using cefdinir in patients with penicillin allergies 1.
- A positive cephalosporin skin test suggests drug-specific IgE antibodies, and the patient should receive a skin test–negative alternative cephalosporin or alternate antibiotic, or the patient should undergo desensitization 1.
From the FDA Drug Label
WARNINGS BEFORE THERAPY WITH CEFDINIR IS INSTITUTED, CAREFUL INQUIRY SHOULD BE MADE TO DETERMINE WHETHER THE PATIENT HAS HAD PREVIOUS HYPERSENSITIVITY REACTIONS TO CEFDINIR, OTHER CEPHALOSPORINS, PENICILLINS, OR OTHER DRUGS IF CEFDINIR IS TO BE GIVEN TO PENICILLIN-SENSITIVE PATIENTS, CAUTION SHOULD BE EXERCISED BECAUSE CROSS-HYPERSENSITIVITY AMONG β-LACTAM ANTIBIOTICS HAS BEEN CLEARLY DOCUMENTED AND MAY OCCUR IN UP TO 10% OF PATIENTS WITH A HISTORY OF PENICILLIN ALLERGY.
Cefdinir and Penicillin Cross-Reactivity:
- Cefdinir should be used with caution in patients with a history of penicillin allergy due to the potential for cross-hypersensitivity among β-lactam antibiotics.
- The risk of cross-hypersensitivity may occur in up to 10% of patients with a history of penicillin allergy 2.
From the Research
Cefdinir Penicillin Cross Reactivity
- Cefdinir is a third-generation cephalosporin, and the cross-reactivity between penicillin and third-generation cephalosporins is considered negligible 3.
- The overall cross-reactivity rate between penicillins and cephalosporins is approximately 1% when using first-generation cephalosporins or cephalosporins with similar R1 side chains 3.
- However, the cross-reactivity between penicillin and cephalosporin drugs occurs in about 2% of cases, which is less than the 8% reported previously 4.
- For penicillin-allergic patients, the use of third- or fourth-generation cephalosporins or cephalosporins with dissimilar side chains than the offending penicillin carries a negligible risk of cross allergy 3.
- Most beta-lactams, including cefdinir, may be safely used in penicillin-allergic patients, with the possible exception of first-generation and second-generation cephalosporins 5.
- Only 1–2% of patients with a confirmed penicillin allergy have an allergy to cephalosporins, making cephalosporins a relatively safe treatment option for patients with a low risk of severe allergic reactions 6.