What is the recommended dosage of amoxicillin (amoxicillin) for dental infections in adults?

Amoxicillin Dosing for Dental Infections in Adults

For most dental infections requiring antibiotics in adults, amoxicillin 500 mg orally three times daily for 5-7 days is the recommended regimen, though surgical intervention (drainage, extraction, or root canal) remains the primary treatment and should never be delayed in favor of antibiotics alone. 1

Critical First Principle: Surgery Over Antibiotics

• Antibiotics should NOT be used as monotherapy for acute dental or apical abscesses - surgical drainage, extraction, or root canal therapy is the definitive treatment 2
• For acute dental abscesses, treatment is only surgical (root canal therapy or tooth extraction) without antibiotics 2
• For acute dentoalveolar abscesses, perform incision and drainage first, then add amoxicillin for 5 days 2
• Studies show no significant difference in pain or swelling outcomes when antibiotics are added to surgical intervention for apical abscesses 2

Standard Amoxicillin Dosing Regimen

Primary recommendation:

• Amoxicillin 500 mg orally three times daily (every 8 hours) for 5-7 days 3, 1
• Alternative dosing: 750-1750 mg/day in divided doses every 8-12 hours 4

Duration considerations:

• 5 days is sufficient for acute dentoalveolar abscesses after surgical drainage 2
• 7-10 days for more complex infections or when systemic involvement is present 3, 1
• One small RCT found 3-day courses non-inferior to 7-day courses for odontogenic infections requiring extraction, though this is not standard practice 5

When to Upgrade to Amoxicillin-Clavulanate (Augmentin)

Consider amoxicillin-clavulanate when:

• Beta-lactamase producing organisms are suspected 1
• Patient has failed initial amoxicillin therapy 3
• More severe infections or immunocompromised patients 3

Dosing options for amoxicillin-clavulanate:

• 875 mg/125 mg twice daily for 5-7 days (preferred for convenience and compliance) 3, 6
• 500 mg/125 mg three times daily for 5-7 days (alternative) 3, 7
• Research demonstrates amoxicillin-clavulanate 875/125 mg BID achieves 88.2% clinical success rates and is non-inferior to clindamycin 6

Penicillin-Allergic Patients

• Clindamycin 300-450 mg three times daily for 7-10 days 3, 1
• Doxycycline 100 mg twice daily for 7-10 days is an alternative 3

Clinical Decision Algorithm

Step 1: Determine if antibiotics are indicated at all

• Do NOT prescribe for: irreversible pulpitis, chronic periodontitis (unless specific adjunctive therapy), or any condition manageable by surgery alone 2
• DO prescribe for: systemic involvement (fever, lymphadenopathy, cellulitis), diffuse swelling, medically compromised patients, or infections extending into soft tissues 2

Step 2: Choose antibiotic regimen

• First-line: Amoxicillin 500 mg TID for 5-7 days 1
• If penicillin-allergic: Clindamycin 300-450 mg TID 3, 1
• If failed amoxicillin or severe: Amoxicillin-clavulanate 875/125 mg BID 3, 6

Step 3: Ensure surgical intervention is not delayed

• Schedule definitive surgical treatment (drainage, extraction, root canal) immediately 2
• Antibiotics are adjunctive only, never primary therapy 2

Common Pitfalls to Avoid

• Never rely solely on antibiotics without surgical intervention - this is the most critical error and leads to treatment failure 2
• Avoid prescribing antibiotics for irreversible pulpitis, which does not benefit from antimicrobial therapy 3
• Do not use prolonged courses (>7 days) for routine infections - 5-7 days is typically sufficient 3, 5
• Avoid using amoxicillin-clavulanate as first-line when plain amoxicillin is adequate - reserve it for treatment failures or suspected resistant organisms 1
• Do not substitute two 250 mg tablets for one 500 mg tablet of amoxicillin-clavulanate, as this results in excessive clavulanate dosing 7

Special Populations

Renal impairment:

• Reduce dose in patients with severe renal impairment (GFR <30 mL/min) 4

Chronic periodontitis (different indication):

• Sub-antimicrobial dose doxycycline 20 mg twice daily for 3-9 months as adjunct to scaling and root planning 2
• Amoxicillin 375 mg + metronidazole 250 mg every 8 hours for 7 days shows superior outcomes when combined with mechanical debridement 2, 8