Antibiotic for Penicillin-Allergic Patient — NDEB AFK MCQ

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ModeratePharmacologyAntibiotic for Penicillin-Allergic PatientNDEB AFK

Which of the following is the most appropriate antibiotic for a patient with a penicillin allergy (anaphylactic type) who has a spreading odontogenic infection?

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Correct answer: A — Clindamycin 300 mg QID plus metronidazole 500 mg TID

For patients with severe (anaphylactic) penicillin allergy who have a spreading odontogenic infection, clindamycin (covers Gram-positive aerobes and most anaerobes) plus metronidazole (covers obligate anaerobes, including beta-lactamase producers) provides broad-spectrum coverage of the polymicrobial oral flora. Cephalosporins (cephalexin) are contraindicated in anaphylactic penicillin allergy due to potential cross-reactivity. Amoxicillin and ampicillin are beta-lactams and are absolutely contraindicated. Azithromycin monotherapy may have insufficient anaerobic coverage for severe infections.

Reference: CDA – Antibiotic Prescribing for Dental Practitioners, 2019