What is the recommended antibiotic treatment for an infected salivary gland?

Antibiotic Treatment for Infected Salivary Gland (Sialadenitis)

For acute bacterial sialadenitis, initiate treatment with either an intravenous cephalosporin (such as cefazolin 1 g every 8 hours) or an oral cephalosporin (such as cephalexin), as these achieve the highest bactericidal concentrations in saliva and cover the primary pathogens Staphylococcus aureus and oral streptococci. 1

Pathogen Coverage and Antibiotic Selection

The most common causative organism in bacterial sialadenitis is Staphylococcus aureus, though viridans streptococci, gram-negative organisms, and anaerobes may also be involved. 2 Your antibiotic choice must achieve adequate salivary concentrations to be effective, as the infection is within the gland tissue and ductal system. 1

First-Line Options (in order of preference):

• Intravenous cephalosporins (for severe infections with systemic signs):

  • Cefazolin 1 g every 8 hours IV achieves the highest salivary concentrations of all antibiotics studied 1
  • Use when patient has fever, significant swelling, or systemic toxicity 2

• Oral cephalosporins (for moderate infections):

  • Cephalexin 500 mg every 6 hours achieves excellent salivary levels 1
  • Appropriate for outpatient management without systemic signs 1

• Fluoroquinolones (alternative first-line):

  • Ciprofloxacin 400 mg every 12 hours IV or 500-750 mg twice daily orally 1
  • Achieves high salivary concentrations and covers gram-negative organisms 1
  • Consider when gram-negative infection suspected or cephalosporin allergy 1

MRSA Considerations:

If MRSA is suspected (healthcare-associated infection, prior MRSA history, or failure of initial therapy):

• Vancomycin 30 mg/kg/day in 2 divided doses IV 3
• Clindamycin 600-900 mg every 8 hours IV or 300-450 mg every 6 hours orally 3
• Note: Clindamycin has bacteriostatic activity and potential for inducible resistance 3

Antibiotics to AVOID:

• Phenoxymethylpenicillin (Penicillin V): Does NOT achieve bactericidal levels in saliva 1
• Tetracyclines: Do NOT reach therapeutic salivary concentrations 1
• Ampicillin-sulbactam alone: While useful for mixed infections in other sites 3, cephalosporins are superior for sialadenitis due to better salivary penetration 1

Critical Adjunctive Measures

Antibiotics alone are insufficient—you must address the underlying pathophysiology:

• Hydration: Aggressive IV or oral fluids to restore salivary flow 2
• Sialagogues: Lemon drops, sour candies, or massage to stimulate saliva production 4, 5
• Warm compresses: Apply to affected gland 4
• Eliminate ductal obstruction: Image for sialoliths if suspected; may require interventional sialoendoscopy or surgical removal 4, 5
• Discontinue xerogenic medications if possible (anticholinergics, antihistamines, diuretics) 2

When to Escalate Care

Surgical intervention becomes necessary if: 4, 2

• Abscess formation develops (requires incision and drainage)
• No improvement after 48-72 hours of appropriate antibiotics
• Complete ductal obstruction that cannot be relieved medically
• Necrotizing infection (rare but life-threatening)

Duration of Therapy

Continue antibiotics for 10-14 days total. 4 Switch from IV to oral therapy once clinical improvement is evident (typically 48-72 hours), using an agent with proven salivary penetration. 1

Common Pitfalls

• Using penicillin-based antibiotics: These do not achieve adequate salivary levels despite being effective for other head and neck infections 1
• Treating with antibiotics alone: Without addressing hydration and ductal obstruction, antibiotics will fail 2
• Assuming viral etiology: Acute bacterial sialadenitis requires antibiotics, unlike viral parotitis (mumps) which is self-limited 6
• Missing abscess formation: Fluctuance or lack of response to antibiotics mandates imaging (ultrasound or CT) to rule out abscess requiring drainage 4, 2