What antibiotic is recommended for a tooth infection?

Antibiotic Treatment for Tooth Infections

Amoxicillin 500 mg three times daily for 5 days is the recommended first-line antibiotic for tooth infections, but only after appropriate surgical drainage or definitive dental treatment has been performed or is immediately planned. 1

Primary Treatment Principle

Surgical intervention is the cornerstone of managing tooth infections and must not be delayed. 1, 2 The infection source—whether through root canal therapy, tooth extraction, or incision and drainage—is the definitive treatment. 2 Antibiotics serve only as adjunctive therapy and should never replace proper surgical management. 1

When Antibiotics Are Actually Indicated

Antibiotics are not routinely needed for most localized dental abscesses. 2 Multiple systematic reviews demonstrate no significant difference in pain or swelling outcomes when antibiotics are added to surgical treatment alone. 2

Prescribe antibiotics only when:

• Systemic involvement is present (fever, malaise, lymphadenopathy) 1, 2
• Diffuse swelling or spreading cellulitis beyond the localized area 1, 2
• Rapidly progressive infection 1
• Patient is immunocompromised or medically compromised 1, 2
• Trismus or difficulty swallowing develops 1
• Adequate surgical drainage cannot be achieved immediately 2

First-Line Antibiotic Regimen

Amoxicillin 500 mg orally three times daily for 5 days is the first choice. 1 This recommendation is based on its effectiveness against the typical polymicrobial flora of odontogenic infections (streptococci, peptostreptococci, and anaerobes), excellent safety profile, and low cost. 3, 4

Pediatric dosing: 45-90 mg/kg/day divided three times daily 5

Penicillin-Allergic Patients

Clindamycin 300-450 mg orally three times daily is the preferred alternative for penicillin-allergic patients. 1, 4 This provides excellent coverage against all odontogenic pathogens. 3

Pediatric dosing: 10-20 mg/kg/day divided into 3 doses 2

Important caveat: For patients with non-anaphylactic penicillin reactions (such as rash only), second- or third-generation cephalosporins (cefdinir, cefuroxime, cefpodoxime) can be safely used, as the historical 10% cross-reactivity rate is an overestimate based on outdated data. 1 However, true type I hypersensitivity (anaphylaxis) is an absolute contraindication to cephalosporins. 1

Second-Line Treatment for Inadequate Response

If the patient fails to improve after 48-72 hours on amoxicillin and adequate surgical drainage has been confirmed, escalate to:

Amoxicillin-clavulanate 875/125 mg twice daily for broader coverage including beta-lactamase producing organisms. 1, 2 This provides enhanced anaerobic coverage critical for complex dental abscesses. 2

Alternative second-line option: Add metronidazole 500 mg three times daily to the existing amoxicillin regimen. 1, 2

Pediatric dosing for amoxicillin-clavulanate: 90 mg/kg/day divided twice daily 2

Severe Infections Requiring Hospitalization

For patients with systemic toxicity, rapidly spreading cellulitis, or deep tissue involvement, consider hospitalization with IV antibiotics:

IV regimens:

• Ampicillin-sulbactam 3 g IV every 6 hours (first choice) 1
• Clindamycin 600-900 mg IV every 6-8 hours (for penicillin allergy) 2
• Piperacillin-tazobactam 3.375 g IV every 6 hours (for severe infections with broader coverage needed) 2

Total antibiotic duration should be 5-10 days based on clinical response, with a maximum of 7 days in most cases with adequate source control. 2

Common Pitfalls to Avoid

Never prescribe antibiotics without ensuring surgical intervention has occurred or is immediately planned. 1 Inadequate surgical drainage is the most common reason for antibiotic failure in dental infections. 1

Do not use metronidazole alone for dental infections, as it lacks activity against facultative streptococci and aerobic organisms commonly present. 1, 3

Avoid fluoroquinolones as they provide inadequate coverage for typical dental abscess pathogens. 2

Do not prescribe antibiotics for:

• Symptomatic irreversible pulpitis 4
• Necrotic pulps without systemic involvement 4
• Localized acute apical abscesses that can be drained 2, 4

Five days is typically sufficient for antibiotic treatment when combined with proper surgical management—avoid unnecessarily prolonged courses. 1