Antibiotics for odontogenic infection
Only with spreading infection or systemic signs; drainage first.
Local measures (drainage, extraction, pulpectomy) first. Antibiotics if spreading cellulitis, fever, lymphadenopathy, trismus.
- Amoxicillin 500 mg TDS × 3–5 days (adult)
- Phenoxymethylpenicillin 500 mg QDS × 3–5 days
- Metronidazole 400 mg TDS × 3–5 days (alone or added)
- Penicillin allergy: clarithromycin 500 mg BD, or metronidazole
- Refer urgently: airway compromise, floor of mouth swelling, dysphagia.
UK vs US
SDCEP: amoxicillin 500 mg TDS or phenoxymethylpenicillin 500 mg QDS for up to 5 days; metronidazole 400 mg TDS; penicillin allergy: clarithromycin 250 mg BD for up to 7 days.
ADA 2019: amoxicillin 500 mg TID or penicillin VK 500 mg QID for 3–7 days. Penicillin allergy: azithromycin 500 mg day 1 then 250 mg daily × 4, or cephalexin 500 mg QID (no anaphylaxis history).
Sources
- SDCEP — Drug Prescribing for DentistryUK
- ADA — Antibiotics for dental pain and swelling guideline (2019)US
- BNF (British National Formulary)UK
Checked against these sources on 2026-10-22. Guidelines change — open the source to confirm.
Summarised from the sources above. Always verify against current local guidelines and the patient's medical history.
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