Mastitis
The regional formulary will not cover all eventualities for infections medicines choices. As with any condition; patient specific factors and sensitivities need to be considered. Please consider this regional formulary advice alongside any relevant local Board guidelines.
Treatment of mastitis / breast abscess associated with lactation
Flucloxacillin
Flucloxacillin 500mg capsules
1g every 6 hours for 7 days.
For penicillin allergy.
Clarithromycin
Clarithromycin 500mg tablets
500mg twice a day for 10-14 days.
Prescribing Notes:
- Treatment course: 7 days depending on clinical response. Infections should begin to respond within 48 hours. If the infection is worsening despite oral antibiotics then seek help from obstetricians, breast unit surgeons or microbiologist. Send a swab of the breast and a MRSA screen if there are risk factors for MRSA infection.
- Management of lactation mastitis in hospital (secondary care) see local board antimicrobial prescribing guidance.
History Notes
30/07/2026
Regional formulary chapter launched.
Treatment of mastitis / breast abscess not associated with lactation
Flucloxacillin
Flucloxacillin 500mg capsules
500mg every 6 hours for 7 days.
Metronidazole
Metronidazole 400mg tablets
400mg every 8 hours for 7 days.
If allergic to penicillin.
Doxycycline
Doxycycline 100mg capsules
100mg twice daily for 7 days.
Metronidazole
Metronidazole 400mg tablets
400mg every 8 hours for 7 days.
Clarithromycin
Clarithromycin 500mg tablets
500mg every 12 hours for 7 days.
Metronidazole
Metronidazole 400mg tablets
400mg every 8 hours for 7 days.
Co-amoxiclav
Co-amoxiclav 500mg/125mg tablets
625mg every 8 hours for 7 days.
History Notes
30/07/2026
Regional formulary chapter launched.