What antibiotics are recommended for a tooth infection?

Antibiotics for Tooth Infection

For uncomplicated tooth infections, amoxicillin-clavulanate (875/125 mg twice daily) is the first-line antibiotic choice, but only when combined with definitive surgical management such as drainage, root canal therapy, or extraction. 1

Primary Treatment Principle

• Surgical intervention is the cornerstone of treatment and must include root canal therapy, extraction, or incision and drainage depending on tooth salvageability. 1
• Antibiotics alone are insufficient for dental abscesses—drainage remains the primary treatment. 1
• Systemic antibiotics should only be given concomitantly with drainage of the dento-alveolar abscess and debridement of the infected tooth. 2

First-Line Antibiotic Selection

Amoxicillin-clavulanate is preferred over plain penicillin or amoxicillin for the following reasons:

• It provides excellent coverage against the polymicrobial nature of odontogenic infections, including both aerobic and anaerobic bacteria commonly found in dental infections. 1, 3
• The addition of clavulanic acid overcomes beta-lactamase producing strains, which have proliferated in recent years. 3
• Dosing: 875/125 mg twice daily (or high-dose 2000/125 mg formulations have shown good results in overcoming resistance). 3, 4
• Plain amoxicillin has little indication for routine treatment of odontogenic infections, though it remains the agent of choice for endocarditis prophylaxis due to higher serum levels. 5

Alternative Regimens

For Penicillin-Allergic Patients:

• Clindamycin (300 mg three times daily) is the drug of choice for confirmed penicillin allergy, as it has excellent activity against all odontogenic pathogens including anaerobes. 1, 6
• Clindamycin is very effective but carries potential gastrointestinal toxicity risk, relegating it to alternative therapy. 5
• Macrolides (erythromycin, clarithromycin, azithromycin) may be used for mild infections in penicillin-allergic patients, though they have higher rates of gastrointestinal disturbances. 5, 3

Second-Line Options (if no improvement in 2-3 days):

• Penicillin V combined with metronidazole to enhance anaerobic coverage. 2, 6
• Cefuroxime (second-generation cephalosporin). 2
• Metronidazole should never be used alone as it is only moderately effective against facultative and anaerobic gram-positive cocci. 5

Duration of Therapy

• A 5-7 day course is typically sufficient for most uncomplicated dental infections. 1
• Treatment should continue until clinical improvement is observed, including resolution of fever, pain, and reduction in swelling. 1
• Lack of therapeutic compliance regarding dosage and treatment duration is a major factor causing antibiotic resistance. 3

Indications Requiring Antibiotics

Antibiotics are indicated when:

• Discrete swelling with systemic involvement (fever, malaise, lymphadenopathy). 1, 6
• Progressive or persistent infections despite local measures. 6
• Presence of enlarged cervical lymph nodes indicating spread beyond the local site. 1
• Medically compromised patients with immunosuppression or altered defense capacity. 6
• Patients with cardiac conditions (infective endocarditis risk, prosthetic valves) or recent prosthetic joint replacement. 6

Antibiotics are NOT indicated for:

• Symptomatic irreversible pulpitis. 6
• Necrotic pulps without systemic signs. 6
• Localized acute apical abscesses that can be drained. 6

Common Pitfalls to Avoid

• Do not prescribe antibiotics without addressing the source of infection surgically—this is the most critical error. 1, 2
• Avoid using plain amoxicillin when amoxicillin-clavulanate is available, as beta-lactamase resistance is increasingly common. 3
• Do not use metronidazole as monotherapy for odontogenic infections. 5
• Tetracyclines have limited role due to high incidence of gastrointestinal disturbances and should only be considered as alternative therapy in penicillin-allergic patients over age 13 who cannot tolerate erythromycin. 5

Microbiology Context

• Odontogenic infections are typically polymicrobial and of indigenous origin. 5
• Principal pathogens include Streptococcus, Peptostreptococcus, Peptococcus, Fusobacterium, Bacteroides, and Actinomyces species. 5
• These infections involve both gram-positive anaerobic/facultative bacteria and gram-negative anaerobic bacilli. 2, 4