From the Guidelines
The risk of cross-reactivity between cefuroxime and amoxicillin in patients with an amoxicillin allergy is low, estimated to be around 1-2%. However, caution is still warranted. For patients with a history of mild to moderate reactions to amoxicillin (such as rash), cefuroxime can generally be used safely 1. In cases of severe allergic reactions to amoxicillin (like anaphylaxis), it's recommended to avoid cefuroxime and consider alternative antibiotics or perform skin testing before administration.
Key Considerations
- The low cross-reactivity is due to the different side chains of these antibiotics, despite both containing a beta-lactam ring 1.
- Cefuroxime, as a second-generation cephalosporin, has a lower risk of cross-reactivity compared to first-generation cephalosporins.
- A detailed allergy history is crucial, as many patients who report penicillin allergies are not truly allergic, and clarifying the nature of the previous reaction can guide decision-making 1.
Administration and Monitoring
If cefuroxime is deemed necessary for a patient with an amoxicillin allergy, consider administering the first dose under medical supervision. Watch for signs of an allergic reaction such as rash, itching, or difficulty breathing. In cases of uncertainty or when cefuroxime is strongly indicated, consider consulting an allergist for skin testing or graded challenge 1.
Alternative Options
Alternative antibiotics may be considered, especially in cases of severe allergic reactions to amoxicillin. The choice of alternative antibiotic should be based on the specific clinical scenario and the patient's medical history 1.
From the Research
Chance of Cross-Reactivity for Cefuroxime in Patients with Amoxicillin Allergy
- The chance of cross-reactivity between penicillin and cephalosporin drugs, such as cefuroxime, is estimated to be around 2% 2.
- A study found that in patients with a history of hypersensitivity reaction to amoxicillin, cefuroxime was found to be safe in 21 out of 62 patients who underwent a stepwise protocol for typing safe alternative antibiotics 3.
- Penicillin cross-reactivity was observed in 16 out of 36 patients (44%) with immediate hypersensitivity, and 3 out of 12 patients (25%) with nonimmediate hypersensitivity 4.
- The negative predictive value of skin tests for penicillin allergy was found to be excellent, excluding severe allergy, and the negative predictive value of the stepwise protocol for typing safe antibiotics was 96% in the first follow-up and 97% in the second follow-up 3.
- A direct oral amoxicillin challenge without preliminary skin testing was found to be safe and effective in adult patients with low-risk reported penicillin allergy, but this does not directly address the cross-reactivity with cefuroxime 5.
Factors Influencing Cross-Reactivity
- The type of reaction to amoxicillin, whether immediate or nonimmediate, can influence the likelihood of cross-reactivity with cefuroxime 4.
- The presence of a positive skin test to penicillin can also increase the likelihood of cross-reactivity 4.
- A thorough clinical history and subsequent appropriate diagnostic testing, including medication challenge, can help establish the diagnosis of allergic reactions to amoxicillin and potential cross-reactivity with cefuroxime 6.