Medicines Q&As
Q&A 306.2
Can a 2 gram dose of flucloxacillin be given as a slow
intravenous injection?
Prepared by UK Medicines Information (UKMi) pharmacists for NHS healthcare professionals
Before using this Q&A, read the disclaimer at www.ukmi.nhs.uk/activities/medicinesQAs/default.asp
Date prepared: March 2012
Background
Flucloxacillin is an isoxazolyl penicillin used primarily for the treatment of infections due to betalactamase-producing staphylococci including otitis externa (1, 2). Other infections include bone
and joint infections, endocarditis, pneumonia, skin infections (including soft-tissue infections), and
toxic shock syndrome (1).
The usual routes of administration for flucloxacillin include oral, intramuscular injection, slow
intravenous injection and intravenous infusion (2-4).
The dosage of flucloxacillin depends on the severity and nature of the infection but when
administered intravenously, recommended doses are usually between 250 mg and 1 gram four
times daily. These doses may be doubled in severe infections (1, 3). Other sources advise 250 mg
to 2 gram every 6 hours (2). Higher doses of up to 8 gram daily in 3 or 4 divided doses may be
given for osteomyelitis; in endocarditis a dose of 8 gram daily in 4 divided doses may be given to
patients weighing up to 85 kg, and 12 gram daily in 6 divided doses may be used in those
weighing more (1).
When administered intravenously it is recommended that flucloxacillin can be given by slow
intravenous injection or by intravenous infusion (3, 4, 6).
Answer
The highest strength of flucloxacillin available on the UK market is 1 gram (3).
However, a 2 gram dose of flucloxacillin can be given as a slow intravenous injection. It is
recommended that each 1 gram vial is reconstituted with 15 to 20ml of water for injection. Once
reconstituted, each vial should be administered slowly over 3 to 4 minutes one after the other, i.e.
6 to 8 minutes in total for a 2 gram dose (3-7).
The suitability of administering a 2 gram dose of flucloxacillin as a slow intravenous injection to a
patient should be made on an individual basis. Furthermore, flucloxacillin is a penicillin and so it is
important to confirm the patient’s allergy status before administering this antibiotic (2).
Summary
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

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Flucloxacillin is an isoxazolyl penicillin used primarily for the treatment of infections due to
beta-lactamase-producing staphylococci.
The usual routes of administration for flucloxacillin include oral, intramuscular injection, slow
intravenous injection and intravenous infusion.
The dosage of flucloxacillin depends on the severity and nature of the infection but when
administered intravenously, recommended doses are usually between 250mg and 1g four
times daily. These doses may be doubled in severe infections. Some information sources
advise 250mg to 2 g every 6 hours.
A 2 gram dose of flucloxacillin can be administered as a slow intravenous injection over 6 to 8
minutes.
The suitability of administering a 2 gram dose of flucloxacillin as a slow intravenous injection to
a patient should be made on an individual basis.
From the NHS Evidence website www.evidence.nhs.uk
1
Version 5.0 Revised July 2009
Limitations
 This Q&A does not take into account the suitability of flucloxacillin in patients with concurrent
disease states, e.g. hepatic or renal failure.
 The suitability of administering a 2 gram dose of flucloxacillin as a slow intravenous injection to
a patient should be made on an individual basis.
References
1. Sweetman S, editor. Martindale: The Complete Drug Reference 37th ed. Flucloxacillin. Date of
revision of the text 03.11.11. Accessed 02.03.12 via www.medicinescomplete.com.
2. Martin J, editor. British National Formulary No 63 London: British Medical Association and The
Royal Pharmaceutical Society of Great Britain; March 2012. Accessed 14.03.12 via
www.bnf.org.uk.
3. Summary of Product Characteristics. Flucloxacillin 1g Powder for Solution for Injection or
Infusion (Wockhardt UK Ltd). Date last updated 29.06.09. Accessed 02.03.12 via
http://www.emc.medicines.org.uk.
4. Klasco R, editor. DRUGDEX® System electronic version. Thomson Micromedex, Greenwood
Village, Colorado, USA. FLOXACILLIN, Drugdex evaluation. Date of revision of text 26.08.11.
Accessed 02.03.12 via http://www.thomsonhc.com.
5. Trissel A. Handbook on Injectable Drugs. Floxacillin Sodium. Accessed 02.03.12 via
www.medicinescomplete.com.
6. Pharmacy Department. University College London Hospitals NHS Foundation Trust. Injectable
Medicines Administration Guide. 3rd ed. Wiley-Blackwell Publishing; 2010, p. 170.
7. Personal Communication. Wockhardt UK Ltd. Contacted 06.03.12
Quality Assurance
Prepared by
Mark Cheeseman, East Anglia Medicines Information Service
Date Prepared
15th March 2012 (partial revision 2nd April 2012)
Checked by
Katie Smith, East Anglia Medicines Information Service
Date of check
20th March 2012 (partial revision checked 2nd April 2012)
Search strategy
 Embase (“exp FLUCLOXACILLIN/ AND exp BOLUS INJECTION/”; “exp FLUCLOXACILLIN/
AND exp INTRAVENOUS DRUG ADMINISTRATION/ AND exp DRUG MEGADOSE/”; “
 Medline (“exp FLOXACILLIN/ AND exp INJECTIONS, INTRAVENOUS/” ; “exp FLOXACILLIN/
AND exp WATER-ELECTROLYTE BALANCE/” )
 In-house database
 Mandell GL, Bennett JE, Dolin R, editors. Mandell, Douglas, and Bennett’s Principles and
Practice of Infectious Diseases. 7th ed. USA: Churchill Livingstone Elsevier; 2010. Accessed
06.03.12 via http://www.expertconsultbook.com/expertconsult/o/login.do?method=display
 Manufacturer (Wockhardt UK Ltd, Drug Safety and Information department). Contacted
06.03.12.
 NeLM Medicines Management ("Flucloxacillin" )

IDISWeb ("floxacillin 8121613" AND "adm parent intravenous 66).
2
From the NHS Evidence website www.evidence.nhs.uk