Mastitis/ Acute Breast Abscess

• Continued breastfeeding is encouraged.

Pathogens

• Common: S. aureus (if lactating), anaerobes (if non-lactating)
• Other: diphtheroids

Drug Treatment

• Severe infection or poor response to regimens below may require parenteral treatment and surgical drainage.
• Duration:
  • 5 days minimum. If abscess, 10 days minimum.
  • Diphtheroids – 4 weeks.

Empiric

If moderate or severe give IV treatment.

Lactating

flucloxacillin HMLSchedNZFPMLnoids Flucloxacillin F: 0.9 Half life: 1 hour Elimination: renal fe: 0.7

PO 1000 mg three times a day

• fe = 0.7, consider adjusting dose if CrCl reduced.
• Risk of hepatotoxicity is increased in females, patients > 55 years old, high doses, and courses longer than 14 days duration.

Mild penicillin allergy

cefalexin HMLSchedNZFPML Cefalexin F: 0.9 Half life: 1 hour Elimination: renal fe: 0.9

PO 500 mg four times a day

• fe = 0.9, consider adjusting dose if CrCl is reduced.

Severe penicillin allergy

clindamycin HMLSchedNZFPMLnoids Clindamycin F: 0.9 Half life: 3 hours Elimination: CYP3A fe: 0.1

PO 450 mg three times a day

• Metabolised by CYP3A. (fe < 0.1).

Non-lactating

amoxicillin+clavulanic acid HMLSchedNZFPMLnoids Amoxicillin+Clavulanic Acid F: 0.9 / 0.5 Half life: 2 hours / 1 hour Elimination: renal fe: 0.9 / 0.5

PO 500 mg/125 mg three times a day

• fe (amoxicillin) = 0.9, fe (clavulanic acid) = 0.5, consider adjusting dose if CrCl reduced.

Mild penicillin allergy

• fe = 0.9, consider adjusting dose if CrCl is reduced.

AND if anaerobes suspected (i.e. subareolar and malodorous):

metronidazole HMLSchedNZFPMLnoids Metronidazole F: 1 Half life: 8 hours Elimination: oxidation, glucuronidation fe: 0.1

PO 600 mg twice a day.

• Metabolised by unknown pathways. (fe = 0.1).

Severe penicillin allergy

• Metabolised by CYP3A. (fe < 0.1).

Pathogens Known

Diphtheroids (non-lactating)

Consult Infectious Diseases, and give:

doxycycline HMLSchedNZFPML Doxazosin F: 0.7 Half life: 12 hours Elimination: CYP3A fe: 0.1

PO 200 mg on day 1 then PO 100 mg once a day

• Metabolised by unknown pathways. (fe = 0.4).
• Avoid in pregnancy and breastfeeding.

If pregnant or lactating

Consult Infectious Diseases/Clinical Microbiology.

Topic Code: 99267

must be prescribed or recommended by a consultant.