Patient leaflet - Flucloxacillin 250 mg powder for solution for injection/infusion
1. What Flucloxacillin is and what it is used for
Flucloxacillin contains the active substance flucloxacillin (as
flucloxacillin sodium monohydrate).
Flucloxacillin is an antibiotic belonging to a class of antibiotics called
beta-lactamase resistant penicillins. Flucloxacillin works by killing
bacteria that cause infections
Flucloxacillin is used to treat a wide range of infections caused by
bacteria which may include:
those affecting the chest (pneumonia, emphysema and lung
abscess)
- tonsils (tonsillitis, quinsy)
- pharynx (pharyngitis)
- sinuses (sinusitis)
- ears (otitis media and otitis externa)
skin and soft tissue (boils, abscesses, carbuncles, impetigo,
cellulites, furunculosis, ulcers and acne)
- wounds, burns and heart (endocarditis)
- bone and joints (osteomyelitis)
- membranes of the brain (meningitis)
- gut (enteritis)
blood (septicaemia) and the kidney, bladder or the urethra (the
tube which carries urine from the bladder).
Flucloxacillin is also indicated for prophylaxis in cardiovascular
surgery (valve prostheses, artery prostheses) and in orthopedic
surgery (arthroplasty, osteosynthesis and arthrotomy) because of the
dominant pathogenic potential of staphylococci during such surgical
procedures.
Flucloxacillin can also be used to prevent infections following skin
drafts or during major surgical procedures, particularly in the heart or
orthopaedic surgery.
2. What you need to know before you use Flucloxacillin
Do not use Flucloxacillin if you:
are allergic to flucloxacillin or other penicillin antibiotics (e.g. (see
symptoms section 4)
have ever had an allergic reaction to any of the other ingredients
of this medicine - see list of ingredients in section 6
a previous history of jaundice/hepatic dysfunction after using
flucloxacillin for ocular or subconjunctival administration
- have had liver problems after taking this medicine (flucloxacillin)
Warnings and precautions
Talk to your doctor or pharmacist before using this medicine:
if you suffer from kidney problems, as you may require lower
dose than normal
- if you suffer from liver problems
- if you are aged 50 or above
- if you have any serious illness other than this infection
- if you have porphyria
if you are on a low sodium diet (See “Flucloxacillin injection
contains sodium”)
if you are taking or will be taking paracetamol. you are being
treated for an infection such as syphilis or leptospirosis
- you are a known carrier of the HLA-B* 5701 allele
There is a risk of blood and fluid abnormality (high anion gap
metabolic acidosis) which occurs when there is an increase in
plasma acidity, when flucloxacillin is used concomitantly with
paracetamol, particularly in certain groups of patients at risk, e.g.
patients with severe renal impairment, sepsis or malnutrition,
especially if the maximum daily doses of paracetamol are used. High
anion gap metabolic acidosis is a serious disease that must have
urgent treatment.
The use of flucloxacillin, especially in high doses, may reduce
the potassium levels in the blood (hypokalemia). Your doctor may
measure your potassium levels regularly during the therapy with higher dose of flucloxacillin.
Other medicines and Flucloxacillin
Tell your doctor or nurse if you are using or have recently taken or might use any other medicines, particularly the following:
- Probenecid (used in the treatment of gout) as this may interfere with how the body removes flucloxacillin
- Bacteriostatic medicinal products such as chloramphenicol, erthromycins, sulphonamides, and tetracyclines (used to treat some infections) may interfere with the bactericidal action of flucloxacillin
- Methotrexate (used to treat some autoimmunitary disorders) can reduce the elimination of flucloxacillin
- Voriconazole (used against fungal infections)
The contraceptive pill as antibiotics can make these less effective
(you may need to use take extra precautions while taking flucloxacillin and for full 7 days after you finish taking it)
- Other antibiotics (used to treat infection)
- Flucloxacillin may also affect the results of some blood and urine tests (Guthrie-test).
Some medicines may affect the way others work. Always tell your doctor about all the medicines you are taking. This means medicines you have bought yourself as well as medicines on prescription from the doctor.
Pregnancy and breast-feeding
If you are pregnant or breast-feeding, think you may be pregnant or are planning to have a baby, ask your doctor for advice before using this medicine.
Flucloxacillin should only be used by pregnant women if considered essential by the doctor.
Flucloxacillin passes into breast milk, so ask your doctor for advice before you receive Flucloxacillin
Test
Regular monitoring of liver or kidney functions should be performed whilst taking flucloxacillin for a long period of time. Tell your doctor that you are taking flucloxacillin if you are having urine tests or blood tests because it may affect the results.
Flucloxacillin contains sodium The maximum recommended daily dose of this medicinal product contains 607.2 mg sodium (found in table salt). This is equivalent to 30.36 % of the adult recommended maximum daily dietary intake for sodium.
Talk to your doctor if you need Flucloxacillin on a daily basis for a prolonged period of time, especially if you have been advised to have a low salt diet.
3. How Flucloxacillin is given
Your medicine is usually given to you by injection into the muscle (intramuscular) or injection into a vein (intravenous). It can also be given to you by injection into a joint (intra-articular) or injection into the lining of the lungs (intrapleural), or by breathing in the medicine from a mask (nebuliser). Flucloxacillin should not be administered into the eye.
Your doctor will decide how much you need each day and how often the injections should be given.
The recommended dose is:
Adults and adolescents over 12 years of age
The usual dose is 1 g – 6 g a day in 3-6 divided doses, given by intravenous or intramuscular injection.
In case of severe infections can be necessary 8 g per day administered in three to four equally divided doses (over 20 to 30 min).
The maximum dose of 12 g per day should not be exceeded
In surgical prophylaxis: 2 g intravenous (bolus or infusion) upon induction of anaesthesia, to be repeated every 6 h for 24 h in cases of vascular and orthopaedic surgery, and for 48 h in cases of cardiac or coronary surgery.
No intramuscular single bolus injection or infusion should exceed 2 g.
Patients with severe kidney disorders
You may be given a lower dose, two or three times a day depending on how well your kidneys are working.
The maximum dose in adults is 1g every 8 to 12 hours. The doses can be increased in more serious infections. To prevent infections after an operation, the usual dose is 1g to 2g before the operation when you are given an anaesthetic. This is then followed by 500mg four times a day for up to three days after your operation.
Children under 12 years of age
The usual daily dose is 25 to 50 mg flucloxacillin per kg of bodyweight given in three to four equally divided doses in a day by intravenous or intramuscular injection.
For severe infections, up to 100 mg/kg a day may be given in three to four divided doses.
No single bolus injection or infusion should exceed 33 mg/kg.
The following information is intended for healthcare professionals only
For single use only. Any unused solution should be discarded.
Preparation of solution
Flucloxacillin may be added to the following intravenous fluids
water for Injections,
sodium chloride 0.9%,
glucose 5%,
sodium chloride 0.18% with glucose 4%
Flucloxacillin may be added to the following infusion fluids:
water for injections,
sodium chloride 0.9%,
glucose 5%,
sodium chloride 0.18% with glucose 4%
Flucloxacillin 500mg Powder for Solution for Injection or Infusion may
be added to the following solution for Intra-articular injection:
water for Injections,
Lignocaine hydrochloride injection.
Intramuscular use
Add 1.5 ml water for Injections to 250 mg vial contents. Add 2.0 ml water for Injections to 500 mg vial contents. Add 3.0 ml water for Injections to 1000 mg vial contents.
Intravenous:
250 mg:
Dissolve 250 mg in 5 ml water for Injections. Administer by slow intravenous injection (three to four minutes). Flucloxacillin may also be added to infusion fluids or injected, suitably diluted, into the drip tube over a period of three to four minutes.
500 mg:
Dissolve 500 mg in 10 ml water for Injections. Administer by slow intravenous injection (three to four minutes). Flucloxacillin may also be added to infusion fluids or injected, suitably diluted, into the drip tube over a period of three to four minutes.
1000 mg :
Dissolve 1000 mg in 20 ml water for injection or 2000 mg in 40 ml water for injections. Administer by slow intravenous injection.
Sign / Date Product
04.05.2026 & 2.10 PM
Team Leader
Initiator
Additional Information :
Artist:
Siva Kumar
Jitendra
40396
Children aged 10 to 14 years usually receive a daily dose of 1.5 g to 2 g and children aged 6 to 10 years 0.75 g to 1.5 g, divided into three to four equal doses.
Premature infants, neonates, sucklings and infants
Flucloxacillin should be administered to premature infants and neonates only after strict risk-benefit assessment because of the possible triggering of kernicterus.
Neonates and premature babies and infants generally receive 40 to 50 mg / kg body weight daily, divided into three to four equal doses. An increase in the daily dose to a maximum of 100 mg / kg body weight may be possible.
Severe kidney disease: your doctor may reduce your dose, maximum dose in adults is 1g every 8 to 12 hours.
The dose can be increased in more serious infections.
To prevent infections after an operation the usual dose is 1 to 2 g before the operation when you are given your anesthetic. This is then followed by 500 mg four times a day for up to three days after our operation.
If you are given more Flucloxacillin injection than you should
As this medicine will normally be given to you by a nurse or a doctor. It is unlikely you will be given too much. If you think you have been given too much Flucloxacillin, tell your doctor or nurse immediately. If you have been given too much, you may feel sick, vomit, and/or have diarrhoea.
If you think you have missed a dose of Flucloxacillin injection
As this medicine will normally be given to you by a nurse or a doctor, it is unlikely you will miss a dose. If you have any concerns, discuss this with your doctor or nurse
If you have any further questions on the use of this medicine, ask your doctor, pharmacist or nurse.
4. Possible side effects
Like all medicines, this medicine can cause side effects, although not everybody gets them.
Tell your doctor immediately if you get any of the following side effects:
severe prolonged diarrhoea, which may have blood or mucus
in it, accompanied by stomach pain and fever. This could be a condition called “pseudomembranous colitis”
notice your urine becoming darker or your faeces (otherwise
known as poo) becoming paler.
- notice your skin or white of your eye turning yellow
sudden wheezing, swelling of your lips, tongue and throat or
body, rash, fainting or difficulties to swallow. These are signs of a severe allergic reaction
reddening of the skin with blisters or peeling. There may also be
severe blisters and bleeding in the lips, eyes, mouth, nose and genitals. This could be “Stevens-Johnson syndrome” or “toxic epidermal necrolysis”.
- convulsions (at high dosage)
tiredness, breathlessness, light-headedness, a rapid weak pulse,
palpitations or headaches, these may be signs of the destruction of red blood cells (causing anemia).
Other side effects include:
Common side effects (may affect up to 1 in 10 people)
Mi.nor gastrointestinal effects such as an upset stomach or
diarrhea
Uncommon side effects (may affect up to 1 in 100 people)
allergic skin reactions e.g. ‘hives’ or ‘nettle’ rash. If you start to
ich or get a rash tell your doctor or nurse at once, and treatment should be discontinued.
- Itchy skin
Very rare side effects (may affect up to 1 in 10,000 people)
hypersensitivity or severe allergic reaction including swollen face
breathing problems.
An unexpected skin reaction, e.g. a rash and/or a sore mouth or
eyes. Tell your doctor or nurse straight away if you notice any of these symptoms and STOP taking flucloxacillin
Abnormal decrease in some types of white blood cells in your
blood (neutropenia) which can make you more likely to get infections
Unusual bleeding or bruising caused by a reduction in the number
of platelets in the blood (thrombocytopenia)
Abnormal increase in a certain type of white blood cells in your
blood (eosinophilia). Symptoms include weight loss, night sweats and fever
Abnormal breakdown of red blood cells (haemolytic anaemia).
Symtoms include tiredness, paleness, yellowing of skin, weakness, dizziness, shortness of breath and fast heart beat
Skin rash, which may blister, and looks like small targets with
central dark spots surrounded by a paler area, with dark ring around the edge (Erythema multiforme)
- Inflammation of the liver (hepatitis)
- Jaundice (cholestatic jaundice)
- Changes to the results of liver function tests
- Joint pain and muscular pain
- Swelling of tubes in the kidney
Fever
- Cases of blood and fluid abnormality (high anion gap metabolic acidosis) which occurs when there is an increase in plasma acidity, when flucloxacillin is used concomitantly with paracetamol, generally in the presence of risk factors (see section 2).
Not known (cannot be estimated from the available data)
- Low potassium levels in the blood (hypokalemia), which can cause muscle weakness, twitching or abnormal heart rhythm.
A red, scaly rash with bumps under the skin and blisters
(exanthematous pustulosis).
Contact a doctor immediately if you get any of these symptoms.
Reporting of side effects
Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via the Yellow Card Scheme at www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store.
5. How to store Flucloxacillin
Keep this medicine out of the sight and reach of children.
Do not use this medicine after the expiry date which is stated on the carton and vial after EXP. The expiry date refers to the last day of that month.
This medicinal product does not require any special storage conditions.
Reconstituted/diluted solution: Chemical and physical in-use stability has been demonstrated for 1 hour at controlled room temperature 20-25°C and for 24 hours at 2-8°C.
From a microbiological point of view, unless the method of opening/ reconstitution/dilution precludes the risk of microbial contamination, the product should be used immediately. If not used immediately, in-use storage times and conditions prior to use are the responsibility of the user and would not be longer than the times stated above for the chemical and physical in-use stability.
Do not use this medicine if you notice visible particles.
For single use only. Discard any unused solution.
Do not throw away any medicines via wastewater or household waste. Ask your pharmacist how to throw away medicines you no longer use. These measures will help protect the environment.
6. Contents of the pack and other information
What Flucloxacillin contains
The active substance is flucloxacillin.
Each vial contains 250 mg flucloxacillin (as flucloxacillin sodium monohydrate)
Each vial contains 500 mg flucloxacillin (as flucloxacillin sodium monohydrate)
Each vial contains 1000 mg flucloxacillin (as flucloxacillin sodium monohydrate)
The other ingredients: none
What Flucloxacillin looks like and contents of the pack
Flucloxacillin is a white or almost white colour powder.
Flucloxacillin 250 mg, 500mg & 1000 mg Powder for Solution for Injection or Infusion is packed in Type-I moulded clear glass vials stoppered with grey chlorobutyl rubber stoppers and sealed with aluminium seals having polypropylene disc.
Packs sizes: Packs of 10 vials
Marketing Authorisation Holder
Eugia (UK) Limited
1 Roundwood Avenue,
Stockley Park,
Uxbridge,
UB11 1AF,
United Kingdom
Manufacturer
APL Swift Services (Malta) Limited
HF26, Hal Far Industrial Estate, Hal Far
Birzebbugia, BBG 3000
Malta
or
Milpharm Limited
1 Roundwood Avenue,
Stockley Park,
Uxbridge,
UB11 1AF,
United Kingdom
This leaflet was last revised in 05/2026
Ref: Ver 2
Flucloxacillin may also be added slowly to infusion fluids or injected, suitably diluted, into the drip tube.
For 250 mg only
Intra-pleural: Dissolve 250 mg in 5-10 ml Water for Injection. Intra-articular: Dissolve 250 mg in up to 5 ml Water for Injections or 0.5% lignocaine hydrochloride solution.
Nebuliser solution: Dissolve 250 mg of the vial contents in 3 ml Water for Injection.
For 500 mg only
Intra-articular: Dissolve 500 mg in up to 5 ml Water for Injections or 0.5% lignocaine hydrochloride solution.
Appearance of the solution
Clear colourless or pale yellow solution, free from visible particles. Reconstituted/diluted solution: Chemical and physical in-use stability has been demonstrated for 1 hour at controlled room temperature 20-25°C or for 24 hours at 2-8°C.
From a microbiological point of view, unless the method of opening/ reconstitution/dilution precludes the risk of microbial contamination, the product should be used immediately. If not used immediately, in-use storage times and conditions prior to use are the responsibility of the user and would not be longer than the times stated above for the chemical and physical in-use stability.
Incompatibilities
Flucloxacillin should not be mixed with blood products or other proteinaceous fluids (e.g. protein hydrolysates) or with intravenous lipid emulsions.
If flucloxacillin is prescribed concurrently with an aminoglycoside, the two antibiotics should not be mixed in the same syringe, intravenous fluid container or giving set; precipitation may occur. Ringer’s solution is not compatible with flucloxacillin for injection/ infusion.