What antibiotics are recommended for the treatment of mastitis?

Antibiotics for Mastitis Treatment

For the treatment of mastitis, dicloxacillin or cephalexin are the first-line antibiotics of choice, as they are effective against Staphylococcus aureus, the most common causative organism. 1

First-Line Treatment Options

• Dicloxacillin 500 mg four times daily orally is the preferred oral agent for methicillin-susceptible strains of S. aureus 2
• Cephalexin 500 mg four times daily orally is an effective alternative, especially for penicillin-allergic patients without immediate hypersensitivity reactions 2
• Clindamycin 300-450 mg three times daily orally is recommended for patients with penicillin allergy 3
• Continued breastfeeding should be encouraged during treatment as it helps with milk removal and generally does not pose a risk to the infant 1

Treatment Duration and Approach

• Treatment duration should typically be 7-14 days to ensure complete resolution 2, 1
• Effective milk removal is an essential part of treatment and may make antibiotics unnecessary in some cases of non-infectious inflammatory mastitis 3
• Culture of breast milk may be necessary in complicated cases to determine the infecting organism and its antibiotic sensitivity 3

Special Considerations

• As methicillin-resistant S. aureus (MRSA) becomes more common, consider alternative antibiotics if MRSA is suspected or confirmed 1
• For MRSA infections, consider trimethoprim-sulfamethoxazole (1-2 double-strength tablets twice daily) or clindamycin (300-450 mg three times daily) 2
• For severe cases requiring hospitalization, intravenous options include:
  • Nafcillin or oxacillin 1-2 g every 4 hours 2
  • Vancomycin 30 mg/kg/day in 2 divided doses for MRSA 2
  • Linezolid 600 mg every 12 hours for resistant organisms 2

Prevention and Management

• Risk of mastitis can be reduced by frequent, complete emptying of the breast and optimizing breastfeeding technique 1
• Sore nipples can precipitate mastitis and should be addressed promptly 1
• Breast abscess is the most common complication of mastitis and can be prevented by early treatment and continued breastfeeding 1
• If an abscess develops, surgical drainage or needle aspiration is needed, but breastfeeding can usually continue 1

Algorithm for Antibiotic Selection

1. For non-severe mastitis in non-penicillin-allergic patients:

   • Dicloxacillin 500 mg four times daily orally for 7-14 days 2, 1

2. For non-severe mastitis in penicillin-allergic patients:

   • Cephalexin 500 mg four times daily orally (if no immediate hypersensitivity) 2
   • Clindamycin 300-450 mg three times daily orally (if immediate hypersensitivity) 2, 3

3. For suspected or confirmed MRSA:

   • Trimethoprim-sulfamethoxazole 1-2 double-strength tablets twice daily 2
   • Clindamycin 300-450 mg three times daily (if susceptible) 2

4. For severe mastitis requiring hospitalization:

   • Nafcillin/oxacillin 1-2 g every 4 hours IV (for MSSA) 2
   • Vancomycin 30 mg/kg/day in 2 divided doses IV (for MRSA) 2