Geriflox is used to treat bacterial infections such as infections of the skin, chest and throat. It works by killing or stopping the growth of bacteria that cause the infection.

How does Geriflox work?

  • Geriflox capsules contain the active ingredient flucloxacillin. Geriflox belongs to a group of antibiotics called penicillins. It is used to treat infections caused by bacteria.
  • Geriflox works by interfering with the ability of bacteria to form cell walls. The cell walls of bacteria are vital for their survival. They keep unwanted substances from entering their cells and stop the contents of their cells from leaking out. Geriflox impairs the bonds that hold the bacterial cell wall together. This allows holes to appear in the cell walls and kills the bacteria.
  • Geriflox differs from other penicillin-type antibiotics. When bacteria become resistant to penicillin antibiotics it is because they produce an enzyme called penicillinase.
This enzyme breaks down the penicillin and makes it ineffective at killing the bacteria. Geriflox is not affected by this enzyme. This means it is used primarily to treat infections caused by bacteria that are resistant to other penicillin-type antibiotics.
  • The types of infection Geriflox is used to treat include: infections affecting the skin and soft tissue (eg boils, cellulitis, impetigo, and infected eczema, ulcers, burns and wounds); bone infections; urinary tract infections; respiratory tract infections (eg pneumonia, sinusitis, lung abcess, pharyngitis, quinsy); meningitis; and blood poisoning (septicaemia). Geriflox is also sometimes used to prevent infections during major surgery, for example bone or heart surgery.
  • To make sure the bacteria causing an infection are susceptible to Geriflox your doctor may take a tissue sample, for example a swab from the throat or skin, or a urine or blood sample.
  • How do I take Geriflox?

    • The dose of this medicine and how long it needs to be taken for depends on the type and severity of infection you have, your age, weight and kidney function. Follow the instructions given by your doctor. These will be printed on the dispensing label that your pharmacist has put on the packet of medicine.
    • Geriflox is usually taken four times a day (every six hours), but follow the instructions given by your doctor. You should try to space the doses evenly throughout the day.
    • Geriflox should be taken on an empty stomach, which means either half an hour to an hour before food or two hours after food.
    • The capsules should be swallowed with liquid.
    • Unless your doctor tells you otherwise, it is important that you finish the prescribed course of this antibiotic medicine, even if you feel better or it seems the infection has cleared up. Stopping the course early increases the chance that the infection will come back and that the bacteria will grow resistant to the antibiotic.


    Alcohol can interact with certain medicines.

    In the case of Geriflox:

    • there are no known interactions between alcohol and Geriflox


    • A medicine is only made available to the public if the clinical trials have shown that the benefits of taking the medicine outweigh the risks.
    • Once a medicine has been licensed, information on the medicine's effects, both intended and unintended, is continuously recorded and updated.
    • Some side-effects may be serious while others may only be a mild inconvenience.
    • Everyone's reaction to a medicine is different. It is difficult to predict which side-effects you will have from taking a particular medicine, or whether you will have any side-effects at all. The important thing is to tell your prescriber or pharmacist if you are having problems with your medicine.

    Common: More than 1 in 100 people who take Geriflox:

    • gastrointestinal problems

    Uncommon: More than 1 in 1000 people who take Geriflox:

    Very rare: Fewer than 1 in 10,000 people who take Geriflox:

    • abnormal laboratory test results
    • blood and bone marrow problems
    • erythema multiforme
    • fever
    • hypersensitivity reactions such as angioedema or anaphylactic shock - some of these reactions may be fatal. Seek medical advice if you get hypersensitivity reactions
    • jaundice
    • joint pain
    • kidney problems
    • liver problems - some liver problems may be fatal
    • muscle pain or tenderness
    • pseudomembranous colitis
    • Stevens-Johnson syndrome
    • toxic epidermal necrolysis

    Taking other medicines

    • If you are taking more than one medicine they may interact with each other. At times your prescriber may decide to use medicines that interact, in other cases this may not be appropriate.
    • The decision to use medicines that interact depends on your specific circumstances. Your prescriber may decide to use medicines that interact, if it is believed that the benefits of taking the medicines together outweigh the risks. In such cases, it may be necessary to alter your dose or monitor you more closely.
    • Tell your prescriber the names of all the medicines that you are taking so that they can consider all possible interactions. This includes all the medicines which have been prescribed by your GP, hospital doctor, dentist, nurse, health visitor, midwife or pharmacist. You must also tell your prescriber about medicines which you have bought over the counter without prescriptions.

    The following medicines may interact with Geriflox:

    • probenecid

    The following types of medicine may interact with Geriflox:

    • oral contraceptives

    If you are taking Geriflox and one of the above medicines or types of medicines, make sure your prescriber knows about it.


    Certain medicines can pass into breast milk and may reach your baby through breast-feeding.

    In the case of Geriflox:

    • you should only take this medicine while breast-feeding if your doctor thinks you need it

    Before you take Geriflox you should discuss breast-feeding with your doctor or midwife. They will help you decide what is best for you and your baby based on the benefits and risks associated with this medicine. You should only breast-feed your baby while taking this medicine on the advice of your doctor or midwife.

    How to store Geriflox

    • Keep all medicines out of the reach and sight of children.
    • Store Geriflox capsules in a cool, dry place, away from direct heat and light.
    • Store Geriflox oral liquid in a refrigerator and do not use it after the expiry date shown on the label.

    If you have any more questions please ask your pharmacist.

    Remember to keep all medicines out of reach of children

    Please Note: We have made every effort to ensure that the content of this information sheet is correct at time of publish, but remember that information about drugs may change. This sheet does not list all the uses and side-effects associated with this drug. For full details please see the drug information leaflet which comes with your medicine. Your doctor will assess your medical circumstances and draw your attention to any information or side-effects which may be relevant in your particular case.


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