Section 1.1

Midwives may independently prescribe, order and administer this drug.

Cloxacillin is a penicillin-type antibiotic and is closely related to methicillin. It interferes with bacteria cell wall formation by weakening the cell wall, causing rupture and killing bacteria.

Indications and Clinical Use:

For the treatment of mastitis caused by susceptible strains of Staphylococcus aureus.


Hypersensitivity to cloxacillin. Any other penicillin allergy.

Warnings and Precautions:

Prolonged use may result in fungal or bacterial superinfection, including C. difficile-associated diarrhea (CDAD) and pseudomembranous colitis; CDAD has been observed >2 months post-antibiotic treatment. Use with caution in patients with renal impairment; modify dosage in severe impairment. Breastfed infants may develop slightly looser stools than normal.


No (Limited) Human Data – Probably Compatible


Category L2 – Limited Data – Probably Compatible

Adverse Reactions:

Upset stomach, diarrhea, vomiting, vaginal infection and mild skin rash.

The following side effects should be reported to a medical practitioner immediately: severe skin rash, itching, hives, difficulty breathing or swallowing, wheezing, unusual bleeding or bruising, sore throat, painful mouth or throat sores, jaundice and diarrhea.

Dosage and Administration:

Mastitis: 500mg PO q6 hours (QID) for 5-7 days if the response is rapid and complete or 10-14 days as indicated.

Cloxacillin should be taken 1 hour before or 2 hours after meals with water. Serum levels are reduced by 50% with food intake.

Onset of Action:

Rapid onset, peak in about 1 hour.


Adults: 0.5-1.5 hours