1 vial 1gm


Flucoxin, Staphlex, Flucloxacillin

  1. Treatment of infections caused by susceptible organisms (particularly susceptible Staph aureus)

250mg, 500mg and 1gm
Add 5ml of Water for injection to 250mg, 500mg or 1gm vial. Shake gently until all the powder is dissolved. Withdraw contents and dilute contents with Water for Injection in the syringe to 10ml for the 250mg and 500mg vials or to 15-20ml for the 1gm vial.
Compatible with the following IV fluids:
Normal saline Dextran solutions 5% dextrose Hartmanns
Glucose and sodium chloride
Solutions prepared for direct IV injection should be prepared immediately before use.
Store at room temperature
Protect from light

Not generally administered by this route in ICU

PO / NG:
Flucloxacillin 500mg capsules (grey/caramel)
Staphlex 250mg and 500mg capsules (black/yellow)
Flucloxacillin oral suspension (white/pinkish)
Note: absorption of oral doses is significantly reduced by food so NG administration is impractical in patients being fed NG


1-2gm 6 hourly


In the 1st week of life use 50mg/kg 12 hourly; in the 2nd to 4th weeks of life use 50mg/kg 8 hourly otherwise 25-50mcg/kg IV 6 hourly

12.5-25mg/kg 6 hourly

Dose in renal impairment [GFR (ml/min)]
<10 dose as in normal renal function up to a total daily dose of 4gm
10-20 dose as in normal renal function
>20-50 dose as in normal renal function

Dose in renal replacement therapy
CAPD dose as in normal renal function up to a total daily dose of 4gm
HD dose as in normal renal function up to a total daily dose of 4gm
CVVHDF dose as in normal renal function

All penicillins inhibit the biosynthesis of the bacterial cell wall. Flucloxacillin is highly resistant to inactivation by staphylococcal penicillinase and is active against penicillinase-producing and non penicillinase-producing strains of Staphylococcus aureus.


  1. A history of allergic reaction to any of the penicillins is a contraindication.

Penicillins are a common cause of anaphylactic reactions
Pseudomembranous colitis
Pseudomembranous colitis has been reported with nearly all antibacterial agents, including flucloxacillin, and may range in severity from mild to life-threatening. Therefore, it is important to consider this diagnosis in patients who present with diarrhoea subsequent to the administration of antibacterial agents.

Prescribing Flucloxacillin in the absence of a proven or strongly suspected bacterial infection or a prophylactic indication is unlikely to provide benefit to the patient and increases the risk of the development of drug resistant bacteria.

Laboratory Tests:
No tests in addition to routine ICU tests are required.

Drug/Laboratory Test Interactions
None noted.

Tetracycline, a bacteriostatic antibiotic, may antagonise the bactericidal effect of penicillin and concurrent use of these drugs should be avoided.

Body as a Whole:
Serum sickness like reactions, Anaphylaxis
Digestive System:
Nausea, vomiting, diarrhoea, and haemorrhagic/pseudomembranous colitis. Hepatic dysfunction including cholestatic jaundice, hepatic cholestasis and acute cytolytic hepatitis have been reported.
Nervous System:
Reversible hyperactivity, agitation, anxiety, insomnia, confusion, convulsions, behavioural changes, and/or dizziness have been reported rarely.
Stevens-Johnson Syndrome, exfoliative dermatitis, toxic epidermal necrolysis, acute generalised exanthematous pustulosis, hypersensitivity vasculitis and urticaria have been reported
Haematological System:
Anaemia, including haemolytic anaemia, thrombocytopaenia, thrombocytopaenic purpura, eosinophilia, leukopaenia, and agranulocytosis have been reported during therapy with penicillins.