Dental Abscess Organism-Specific Therapy

Most dental abscesses respond to surgical treatment (incision and drainage, root canal, or extraction) and elimination of the source of infection. The addition of antibiotics is not recommended for a localized dental abscess. Antibiotics are indicated if drainage is not possible or if the patient shows signs of systemic involvement or is immunocompromised. ^[1] The duration of therapy should be 7 days. ^{[2, 3, 4, 5, 6]}

Organism-specific therapeutic regimens for dental abscess are provided below, including those for Fusobacterium, Bacteroides, Prevotella, Peptostreptococcus, Streptococcus, and Actinomyces. ^[7]

Fusobacterium

See the list below:

• Penicillin VK 500mg PO TID or penicillin G potassium 2-4 million U IV/IM q4-6h
• Up to 50% of Fusobacterium nucleatum and 20% of Fusobacterium necrophorum isolates produce beta-lactamases, making them resistant to penicillin, ampicillin, and some cephalosporins ^[8]

If penicillin allergic:Clindamycin 300-450mg PO TID-QID or 600-900mg IV q6-8h

• Duration of therapy: 7days

Bacteroides

See the list below:

• Amoxicillin-clavulanate 500mg/125mg PO TID or
• Amoxicillin-clavulanate 875mg/125mg PO BID
• Some Bacteroides species produce beta-lactamase

If penicillin allergic:

• Metronidazole 250-500mg PO TID or  cefoxitin 1-2g IV q6h or  cefotetan 2g IV q12h
• Duration of therapy: 7days

Prevotella

See the list below:

• Amoxicillin-clavulanate 500mg/125mg PO TID or
• Amoxicillin-clavulanate 875mg/125mg PO BID
• Duration of therapy: 7days
• Approximately 50% of Prevotella species produce beta-lactamases

If penicillin allergic:

• Cefoxitin 1-2g IV q6h or  metronidazole 250-500mg PO TID or clindamycin 300-450mg PO TID-QID or 600-900mg IV q6-8h
• Duration of therapy: 7days

Peptostreptococcus

See the list below:

• Amoxicillin 500mg PO TID or 1g PO BID or
• Penicillin VK 250-500mg PO TID-QID or
• Penicillin G 2-4 million U IV/IM q4-6h or
• Clindamycin 300-450mg PO TID-QID or 600-900mg IV q6-8h or
• Cefotetan 2g IV q12h
• Duration of therapy: 7days

Streptococcus species

See the list below:

• Amoxicillin 500mg PO BID or
• Penicillin V 250-500mg PO TID-QID or
• Penicillin G 2-4 million U IV/IM q4-6h or
• Clindamycin 300-450mg PO TID-QID or 600-900mg IV q6-8h or
• Cefoxitin 1-2g IV q6h or
• Cefotetan 2g IV q12h
• Duration of therapy: 7days

Actinomyces

See the list below:

• Penicillin G 2-4 million U IV/IM q4-6h ^[6] or
• Clindamycin 600mg IV q8h or
• Doxycycline 100mg PO BID
• Duration of therapy: 7days
• All Actinomyces isolates are resistant to ciprofloxacin and metronidazole

For all weight-based pediatric doses listed below, ^[9] do not exceed adult dose. ^{[8, 10]}

Fusobacterium

See the list below:

• Penicillin VK 25-50mg/kg/day PO divided TID/QID or
• Penicillin G potassium 100,000-400,000U/kg/day IV divided q6h, not to exceed 24 million U/day
• Up to 50% of Fusobacterium nucleatum and 20% of Fusobacterium necrophorum isolates produce beta-lactamases, making them resistant to penicillin, ampicillin, and some cephalosporins ^[8]

If penicillin allergic:

• Clindamycin 30mg/kg/day PO/IV/IM divided q6-8h or
• Metronidazole 30-50mg/kg/day PO or 22.5-40 mg/kg/day IV divided q8h
• Duration of therapy: 7days

Bacteroides

See the list below:

• Amoxicillin/clavulanate (dosage based on amoxicillin component)
• 4:1 dosage form: 20-40mg/kg/day PO divided q8h, not to exceed 500mg/125mg PO TID or
• 7:1 dosage form: 25-45mg/kg/day PO divided q12h, not to exceed 875mg/125mg PO BID
• Ampicillin/sulbactam 100-200mg/kg/day IV divided q6h, not to exceed 4g of ampicillin
• Some Bacteroides species produce beta-lactamase

If penicillin allergic:

• Metronidazole 30-50mg/kg/day PO divided q8h or
• Cefoxitin 80-160mg/kg/day IV divided q6h, not to exceed 12 g/day, or
• Cefotetan 40-80mg/kg/day IV divided q12h, not to exceed 6 g/day
• Duration of therapy: 7days

Prevotella

See the list below:

• Amoxicillin/clavulanate (dosage based on amoxicillin component)
• 4:1 dosage form: 20-40mg/kg/day PO divided q8h, not to exceed 500mg/125mg PO TID or
• 7:1 dosage form: 25-45mg/kg/day PO divided q12h, not to exceed 875mg/125mg PO BID
• Ampicillin/sulbactam 100-400mg/kg/day IV divided q6h, not to exceed 8 g/d ampicillin
• Approximately 50% of Prevotella species produce beta-lactamases

If penicillin allergic:

• Cefoxitin 80-160mg/kg/day IV divided q6h or
• Metronidazole 30-50mg/kg/day PO divided q8h or
• Clindamycin 30 mg/kg/day PO/IV/IM divided q6-8h
• Duration of therapy: 7days

Peptostreptococcus

See the list below:

• Amoxicillin 25-50mg/kg/day PO divided TID or
• Penicillin VK 25-50mg/kg/day PO divided TID/QID or
• Penicillin G potassium 100,000-400,000U/kg/day IV divided q6h, not to exceed 24 million U/day, or
• Clindamycin 30mg/kg/day PO/IV/IM divided q6-8h or
• Cefotetan 40-80mg/kg/day IV divided q12h, not to exceed 6 g/day,
• Duration of therapy: 7days

Streptococcus species

See the list below:

• Amoxicillin 25-50mg/kg/day PO divided TID or
• PenicillinVK 25-50mg/kg/day PO divided TID/QID or
• Penicillin G potassium 100,000-400,000U/kg/day IV divided q6h, not to exceed 24 million U/day, or
• Clindamycin 30mg/kg/day PO/IV/IM divided q6-8h or
• Cefoxitin 80-160mg/kg/day IV divided q6h, not to exceed 12 g/day, or
• Cefotetan 40-80mg/kg/day IV divided q12h, not to exceed 6 g/day
• Duration of therapy: 7days

Actinomyces

See the list below:

• Penicillin G potassium 100,000-400,000U/kg/day IV divided q6h, not exceed 24 million U/day, or
• Clindamycin 30mg/kg/day IV divided q6-8h or
• Doxycycline (children older than 8 y) 2-4mg/kg PO once daily or divided BID
• Duration of therapy: 7days
• All Actinomyces isolates are resistant to ciprofloxacin and metronidazole