What antibiotics are used to treat a tooth infection?

Antibiotics for Tooth Infection

Primary Treatment Principle

Surgical intervention (drainage, extraction, or root canal) is the definitive treatment for tooth infections, with antibiotics serving only as adjunctive therapy—never as standalone treatment. 1, 2

First-Line Antibiotic Regimen

Amoxicillin 500 mg orally three times daily for 5 days is the first-line antibiotic choice following appropriate surgical intervention. 1, 2

• This regimen is recommended by the American Dental Association and American College of Dentistry as the standard adjunctive therapy 1, 2
• Amoxicillin achieves peak blood levels of 5.5-7.5 mcg/mL within 1-2 hours and maintains therapeutic levels for 8 hours 3
• The 5-day duration is typically sufficient; avoid prolonged courses when not indicated 1

When Antibiotics Are Actually Indicated

Antibiotics should not be routinely prescribed for simple dental infections in healthy patients, as surgical drainage alone is often sufficient. 2 Antibiotics are specifically indicated when:

• Systemic involvement is present (fever, lymphadenopathy, malaise) 2
• Diffuse swelling or cellulitis extends beyond the immediate infection site 2
• Immunocompromised status (diabetes, HIV, chemotherapy, chronic steroid use) 2
• Progressive infection despite adequate surgical management 2
• Rapidly spreading cellulitis or systemic toxicity requiring hospitalization 1

Second-Line Options for Treatment Failure or Severe Infection

If there is inadequate response to amoxicillin alone or the infection is more severe, switch to amoxicillin-clavulanic acid 875/125 mg orally twice daily for 5 days. 1, 2

• Amoxicillin-clavulanic acid provides broader coverage against beta-lactamase producing organisms 4
• Clinical success rates are comparable to clindamycin (88.2% versus 89.7%) 4
• Before switching antibiotics, always verify that adequate surgical drainage has been performed—this is the most common reason for antibiotic failure 1

Penicillin-Allergic Patients

For patients with penicillin allergy, clindamycin 300-400 mg orally three times daily for 5 days is the preferred alternative. 1, 2

• Clindamycin is very effective against all odontogenic pathogens 5
• Erythromycin may be used for mild infections in penicillin-allergic patients, though gastrointestinal side effects are common 5, 6
• Avoid macrolides as first choice due to inferior efficacy compared to clindamycin 7

Critical Pitfalls to Avoid

• Never prescribe antibiotics without ensuring surgical intervention has been performed or is immediately planned 1, 2
• Do not use metronidazole alone—it lacks activity against facultative streptococci and aerobic organisms commonly present in dental infections 1, 5
• Avoid tetracyclines as first-line therapy due to high incidence of gastrointestinal disturbances and limited efficacy 5, 6
• Do not simply switch antibiotics for treatment failure without confirming adequate surgical drainage—inadequate source control is the primary cause of antibiotic failure 1

Special Situations Requiring Escalation

For suspected MRSA infections or patients with systemic toxicity requiring hospitalization, consider intravenous therapy with vancomycin, linezolid, or daptomycin. 1 If necrotizing fasciitis is suspected with extension into cervicofacial soft tissues, immediate surgical consultation and prompt antibiotic therapy are crucial. 1, 2