Will Omnicef (Cefdinir) or Biaxin (Clarithromycin) provide adequate coverage for a patient with a known allergy to Augmentin (Amoxicillin-Clavulanate)?

From the Guidelines

If you are allergic to Augmentin, Biaxin (clarithromycin) is a safer choice than Omnicef (cefdinir) for treating ear infections, especially in cases of severe penicillin allergy, due to its lack of cross-reactivity with penicillins 1. When considering alternative antibiotics for someone allergic to Augmentin, it's crucial to weigh the risks and benefits, particularly in the context of penicillin allergy.

• Omnicef, being a cephalosporin, carries a risk of cross-reactivity in patients with penicillin allergies, although this risk is generally considered low for later-generation cephalosporins like cefdinir 1.
• Biaxin, a macrolide antibiotic, does not have structural similarity to penicillins, making it a preferable option for those with penicillin allergies, as it minimizes the risk of an allergic reaction 1. Key considerations include:
• The severity of the penicillin allergy: For severe allergies, avoiding any potential cross-reactivity is paramount.
• The specific type of ear infection: The choice of antibiotic should also be guided by the causative pathogen and local resistance patterns.
• Patient's medical history: Informing healthcare providers about the Augmentin allergy is crucial for selecting the most appropriate alternative antibiotic. Given the most recent and highest quality evidence, Biaxin (clarithromycin) is recommended for patients allergic to Augmentin, especially in cases of severe penicillin allergy, due to its safety profile and efficacy in treating ear infections 1.

From the FDA Drug Label

CONTRAINDICATIONS Cefdinir is contraindicated in patients with known allergy to the cephalosporin class of antibiotics. 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.

Allergic Reaction Considerations

• Patients with a known allergy to Augmentin (a penicillin-class antibiotic) may be at risk for cross-hypersensitivity reactions to other β-lactam antibiotics, including cefdinir (Omnicef).
• Cefdinir is contraindicated in patients with a known allergy to the cephalosporin class of antibiotics.
• Biaxin is not a β-lactam antibiotic, but its effectiveness against ERAS (not specified which type of ERAS) is not directly addressed in the provided drug labels.
• Due to the potential for cross-hypersensitivity, caution should be exercised when considering Omnicef for patients with a penicillin allergy. The FDA drug label does not answer the question.

From the Research

Allergic Reactions to Augmentin

• Patients allergic to Augmentin may be concerned about alternative antibiotic options, such as Omnicef or Biaxin, for treating infections like ERAS (Early Respiratory Acute Syndrome)
• According to 2, approximately 10% of the US population reports allergies to β-lactam agents like penicillin, but clinically significant IgE-mediated or T lymphocyte-mediated penicillin hypersensitivity is uncommon (<5%)
• Cross-reactivity between penicillin and cephalosporin drugs, such as Omnicef, occurs in about 2% of cases 2

Alternative Antibiotic Options

• Omnicef (cefdinir) is a third-generation cephalosporin antibiotic that may be effective against certain bacterial infections
• Biaxin (clarithromycin) is a macrolide antibiotic that may be used as an alternative to β-lactam antibiotics in patients with allergies
• However, the effectiveness of these antibiotics against ERAS infections is not explicitly stated in the provided studies

Antibiotic Allergy Evaluation

• Evaluation of penicillin allergy before deciding not to use penicillin or other β-lactam antibiotics is an important tool for antimicrobial stewardship 2
• Direct amoxicillin challenge is appropriate for patients with low-risk allergy histories, while moderate-risk patients can be evaluated with penicillin skin testing 2
• Clinicians should identify the methods supported by their available resources to evaluate antibiotic allergies 2

Preoperative Antibiotic Selection

• Recent studies have demonstrated that having a penicillin allergy label results in a 50% increased odds of surgical site infection among patients reporting a penicillin allergy entirely attributable to the use of a beta-lactam alternative antibiotic 3
• A new set of guidelines and a risk stratification tool are proposed for assessing allergies and determining appropriate antibiotic choice, dosage, and timing in the orthopaedic preoperative setting 3