From the Guidelines
No, a patient with an allergy to erythromycin is not likely to have an allergy to clindamycin. These antibiotics belong to different structural classes - erythromycin is a macrolide antibiotic while clindamycin is a lincosamide. Cross-reactivity between these classes is rare, occurring in less than 10% of patients, as confirmed by a systematic literature review 1. This means that most patients who cannot tolerate erythromycin can safely use clindamycin as an alternative. However, caution is still warranted when prescribing clindamycin to patients with a history of severe allergic reactions to erythromycin. In such cases, healthcare providers might consider starting with a test dose or using closer monitoring during initial administration. The low cross-reactivity is due to the significant differences in chemical structure between these antibiotic classes, despite some similarities in their mechanism of action (both affect bacterial protein synthesis, but bind to different sites on the bacterial ribosome). Some key points to consider when assessing the risk of cross-reactivity include:
- The time elapsed since the index reaction
- Structured allergy anamnesis to assess the risk of recurrence of a (severe) allergic reaction, as outlined in the guideline by the Dutch Working Party on Antibiotic Policy (SWAB) 1
- The implementation of recommendations to use smaller spectrum antibiotics with fewer side effects, less toxicity, and potentially lower risks of antibiotic resistance. It is essential to follow a more liberal approach towards patients with suspected antibiotic allergy, as supported by the guideline 1, to ensure the best possible outcome in terms of morbidity, mortality, and quality of life.
From the Research
Allergy to Erythromycin and Clindamycin
- There is no direct evidence to suggest that a patient with an allergy to erythromycin is likely to have an allergy to clindamycin, as the provided studies do not investigate cross-reactivity between these two antibiotics 2, 3, 4, 5, 6.
- Erythromycin and clindamycin are both antibiotics, but they belong to different classes: macrolides and lincosamides, respectively 3.
- The studies focus on the use of erythromycin and clindamycin as alternative antibiotic prophylaxis for patients with penicillin or cephalosporin allergies 2, 4.
- Anaphylaxis to erythromycin has been reported, and the management of antibiotic allergy involves identification of the putative antibiotic, avoidance, and potential desensitization 5, 6.
- The provided evidence does not support a conclusion about the likelihood of cross-reactivity between erythromycin and clindamycin allergies, and more research would be needed to determine this 2, 3, 4, 5, 6.
Key Findings
- Erythromycin and clindamycin are used as alternative antibiotic prophylaxis for patients with penicillin or cephalosporin allergies 2, 4.
- Anaphylaxis to erythromycin has been reported, and the management of antibiotic allergy involves identification of the putative antibiotic, avoidance, and potential desensitization 5, 6.
- The studies do not investigate cross-reactivity between erythromycin and clindamycin allergies 2, 3, 4, 5, 6.
Antibiotic Allergy Management
- The management of antibiotic allergy begins with the identification of the putative antibiotic from a detailed and accurate drug history, complemented by validated in-vivo and in-vitro allergological tests 6.
- Knowledge of the evidence for specific antibiotic cross-reactivities is also important in patient education 6.
- Drug desensitization may be considered in certain situations where the benefits outweigh the risks, and where no alternative antibiotics can be used 6.