From the Guidelines
Cefdinir can be considered a viable antibiotic option for patients with an amoxicillin allergy, but with caution, as the risk of cross-reactivity is lower than previously assumed, according to the most recent guidelines 1. When considering cefdinir for a patient with an amoxicillin allergy, it's essential to evaluate the nature of the allergy and the severity of the reaction.
- For patients with a history of severe reactions, such as anaphylaxis, angioedema, or Stevens-Johnson syndrome, cefdinir should be avoided completely.
- For patients with mild reactions, such as a non-itchy rash, cefdinir might be used with careful monitoring. The chemical structure of cefdinir differs from amoxicillin, which explains why most patients with amoxicillin allergies can tolerate it, but the shared beta-lactam ring in both medications accounts for the potential cross-reactivity 1. Recent guidelines suggest that the risk of cross-reactivity between penicillins and cephalosporins is lower than previously assumed, and that cefdinir, a third-generation cephalosporin, is highly unlikely to be associated with cross-reactivity with penicillin allergy 1. It's crucial to inform healthcare providers about the amoxicillin allergy before taking cefdinir, as they may need to consider alternative antibiotics or perform allergy testing. The most recent study 1 supports a more liberal approach towards patients with suspected antibiotic allergy, and suggests that cefdinir can be a viable option for patients with an amoxicillin allergy, with careful evaluation and monitoring.
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 Allergy and Amox Allergy Relationship:
- Patients with a history of penicillin allergy (e.g., amoxicillin) may be at risk of cross-hypersensitivity to cefdinir.
- Caution should be exercised when administering cefdinir to patients with a known penicillin allergy, as the risk of an allergic reaction may be increased (up to 10% of patients) 2.
- A careful medical history is necessary to determine if a patient has had previous hypersensitivity reactions to cefdinir, other cephalosporins, penicillins, or other drugs.
From the Research
Cefdinir Allergy to Amox
- Cefdinir is a third-generation cephalosporin with a broad spectrum of antibacterial activity, effective against many pathogens commonly causative in infections of the respiratory tract or skin and skin structure 3.
- The cross-reactivity between penicillin and cephalosporin drugs occurs in about 2% of cases, less than the 8% reported previously 4.
- For patients with a history of penicillin allergy, 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 5.
- Cefdinir has shown good clinical and bacteriological efficacy in the treatment of a wide range of mild-to-moderate infections of the respiratory tract and skin in adults, adolescents, and pediatric patients, and is usually well tolerated 3.
- The overall cross-reactivity rate between penicillins and cephalosporins is lower than previously reported, though there is a strong association between amoxicillin and ampicillin with first- and second-generation cephalosporins that share a similar R1 side chain 5.
Treatment Options
- Extended-spectrum cephalosporins, such as cefdinir, are recommended as one of the first-line options for the treatment of acute bacterial rhinosinusitis (ABRS) in adults 6.
- Cefdinir may be considered an effective alternative to amoxicillin in adults who are allergic to penicillin 6.
- The use of cephalosporins in penicillin-allergic patients is supported by the low rate of cross reactions between both groups of antibiotics 5.