What are the recommended antibiotics for bacterial parotitis?

Recommended Antibiotics for Bacterial Parotitis

Dicloxacillin or amoxicillin-clavulanate are the first-line antibiotics for bacterial parotitis, with clindamycin as an alternative for penicillin-allergic patients. 1

Microbiology of Bacterial Parotitis

• The most common pathogen in acute bacterial parotitis is Staphylococcus aureus 2, 3
• Other common pathogens include:
  • Anaerobic bacteria (Prevotella, Porphyromonas, Fusobacterium, Peptostreptococcus) 2, 4
  • Streptococcus species 2
  • Gram-negative bacilli (especially in hospitalized patients) 2, 5

First-Line Antibiotic Recommendations

For Outpatient Treatment (Mild-Moderate Cases):

• Dicloxacillin: 500 mg orally 4 times per day 1

  • Excellent coverage for methicillin-susceptible S. aureus (MSSA)
  • Duration: 7-10 days depending on clinical response

• Amoxicillin-clavulanate: 875/125 mg orally twice per day 1

  • Provides broader coverage including S. aureus and many anaerobes
  • Better choice if mixed infection with anaerobes is suspected
  • Duration: 7-10 days depending on clinical response

For Penicillin-Allergic Patients:

• Clindamycin: 300-450 mg orally 3 times per day 1
  • Good coverage for S. aureus, streptococci, and anaerobes
  • Duration: 7-10 days depending on clinical response

For Severe Infections or Inpatient Treatment:

• Oxacillin or Nafcillin: 1-2 g IV every 4-6 hours 1

  • Parenteral drug of choice for MSSA infections

• Ampicillin-sulbactam: 1.5-3.0 g IV every 6 hours 1

  • Broader coverage for mixed infections

• For MRSA coverage when suspected: Vancomycin 15-20 mg/kg IV every 8-12 hours 1

Special Considerations

• For hospitalized patients: Consider coverage for gram-negative organisms with combination therapy 3

  • Add an aminoglycoside if gram-negative infection is suspected 3

• For immunocompromised patients: Broader empiric coverage may be needed due to higher risk of unusual or resistant pathogens 5

• If anaerobic infection is suspected: Ensure coverage with amoxicillin-clavulanate, clindamycin, or metronidazole 4

Treatment Algorithm

1. Assess severity:

   • Mild-moderate (outpatient): Oral antibiotics
   • Severe (inpatient): IV antibiotics

2. Select antibiotic based on likely pathogens:

   • Community-acquired: Target S. aureus primarily
   • Hospital-acquired: Consider broader coverage including gram-negatives

3. Adjust based on allergies:

   • Non-anaphylactic penicillin allergy: Consider cephalosporins
   • Severe penicillin allergy: Use clindamycin or fluoroquinolones

4. Reassess in 72 hours:

   • If improving: Complete course
   • If not improving: Consider drainage procedure and culture-guided therapy 2

Pitfalls and Caveats

• Failure to recognize anaerobic involvement can lead to treatment failure; ensure adequate anaerobic coverage if patient is not responding to anti-staphylococcal therapy alone 4

• Hydration status significantly affects treatment success - ensure adequate hydration to promote salivary flow 2

• Antibiotic concentrations in purulent parotid saliva may differ from those in normal saliva, potentially affecting treatment efficacy 6

• For recurrent parotitis, consider underlying conditions (e.g., Sjögren's syndrome, ductal obstruction) that may predispose to infection 3