Mastitis - Antibiotic Prescribing

Note higher and more frequent 6-hourly doses of antibiotics are required in mastitis treatment to ensure adequate tissue penetration.
Low dose i.e., 250mg or 8-hourly dosing may result in treatment failure.
Duration of treatment required can vary from 5 to 10 days.
Patients should be reassessed after 5 days as treatment failures do occur and referral to hospital may be necessary if not responding to treatment. If improving but not fully resolved, extend treatment course.
The patient should be encouraged to either breastfeed or express to ensure milk stasis does not occur. Cold compresses and analgesia should be used

Drug	Dose	Duration	+/- Notes
1st choice options
Flucloxacillin	500mg-1g every 6 hours	5 to 10 days	Reassess after 5 days of treatment as failures do occur and referral to hospital may be necessary if not responding to treatment. If improving but not fully recovered extend treatment course.
2nd choice options / Penicillin Allergy
Clindamycin	300mg-450mg every 6 hours	5 to 10 days

Visit HSE My Child website for further information further information on Mastitis while breast feeding
An information sheet on ‘Antibiotics and breastfeeding' is available from the Breastfeeding Network UK
Further information on Antibiotics and Breast-feeding can be found on the Mother to Baby website (USA) (Search or Use Browse by Medications category).
Visit HPSC Information Leaflets pages for the General Public, (MRSA, CRE, etc)

Doses are oral and for adults unless otherwise stated
Dosing in children quick reference dosage/weight guide
Penicillin allergy – tips on prescribing in penicillin allergy
Renal impairment dosing table
Safety in Pregnancy and Lactation
Drug interactions table. Extensive drug interactions for clarithromycin, fluoroquinolones, azole antifungals and rifampicin. Many antibiotics increase the risk of bleeding with anticoagulants.
Visit the Health Products Regulatory Authority (HPRA) website for detailed drug information (summary of product characteristics and patient information leaflets). Dosing details, contraindications and drug interactions can also be found in the Irish Medicines Formulary (IMF) or other reference sources such as British National Formulary (BNF) / BNF for children (BNFC).

Reviewed May 2022, minor update April 2024