What are the first line antibiotics for mastitis in breastfeeding women?

First-Line Antibiotics for Mastitis in Breastfeeding Women

Dicloxacillin or cephalexin are the first-line antibiotics for mastitis in breastfeeding women due to their effectiveness against Staphylococcus aureus, which is the most common causative organism. 1

Recommended First-Line Antibiotics

• Dicloxacillin: Preferred first-line treatment due to its effectiveness against Staphylococcus aureus, including beta-lactamase producing strains 1, 2

  • Extremely low transfer into breast milk (relative infant dose of only 0.03%), making it very safe during breastfeeding 3
  • Standard dosing: 500 mg orally every 6 hours 3

• Cephalexin (first-generation cephalosporin): Alternative first-line option with similar efficacy against S. aureus 1

  • Cephalosporins are generally considered safe during breastfeeding 4

Treatment Approach

1. Continue breastfeeding during antibiotic treatment:

   • Frequent, complete emptying of the breast is essential for treatment success 1, 5
   • Continued breastfeeding does not pose a risk to the infant and helps resolve the mastitis 4, 1

2. Duration of therapy:

   • Typically 10-14 days of antibiotics to prevent recurrence and complications 5

3. Supportive measures (in addition to antibiotics):

   • Ensure proper latch and breastfeeding technique 1
   • Apply warm compresses before feeding to improve milk flow 5
   • Consider pain medication (e.g., ibuprofen) for pain and inflammation 5

Alternative Antibiotics (if penicillin allergy or treatment failure)

• Clindamycin: Effective against S. aureus including some MRSA strains 6

  • Present in breast milk but generally compatible with breastfeeding 6
  • Monitor infant for possible gastrointestinal effects such as diarrhea 6

• Amoxicillin/clavulanic acid: Effective broad-spectrum option 4

  • Safe during breastfeeding based on limited human data 4

• Erythromycin or azithromycin: Alternative for penicillin-allergic patients 4

  • Note: There is a very low risk of infantile hypertrophic pyloric stenosis in infants exposed to macrolides during the first 13 days of breastfeeding 4

Special Considerations

• MRSA: As methicillin-resistant S. aureus becomes more common, it may become a more frequent cause of mastitis requiring different antibiotic choices 1

• Culture and sensitivity testing: Consider if no improvement after 48 hours of treatment or in cases of recurrent mastitis 5

• Abscess formation: Most common complication of inadequately treated mastitis, requiring surgical drainage or needle aspiration 1

• Candida infection: May develop as a result of antibiotic therapy; requires appropriate antifungal treatment 5

Monitoring and Follow-up

• Improvement should be seen within 48-72 hours of starting antibiotics 5
• If symptoms worsen or do not improve within this timeframe, reevaluation is necessary to:
  • Rule out an abscess
  • Consider alternative antibiotics based on culture results
  • Evaluate for other causes of symptoms 1, 5

Remember that effective milk removal through continued breastfeeding or expression is a critical component of treatment, and in some cases of non-infectious inflammatory mastitis, may be sufficient without antibiotics 7, 2.