How does it work?

Cubicin infusion contains the active ingredient daptomycin, which is a medicine used to treat infections with bacteria, in particular Staphylococcus aureus bacteria. Daptomycin is a new type of antibiotic known as a lipopeptide antibiotic. It can only be used to treat infections with a specific sub-group of bacteria called Gram positive bacteria.

Daptomycin works by binding to the cell membranes of Gram positive bacteria, causing them to lose potassium. This causes a reaction that rapidly stops the bacteria making proteins and genetic material that they need to survive and multiply. This kills the bacteria and treats the infection.

Daptomycin has a different mechanism of action to all the other classes of antibiotics. This means it can be used to treat Gram positive bacterial infections that are resistant to other antibiotics. An example of this is infection with the "superbug" MRSA (methicillin-resistant staphylococcus aureus). Such bacterial infections have become more common, particularly in hospitals, due to increasing resistance of bacteria to antibiotic treatment. As daptomycin works in a different way to other antibiotics, it may provide doctors with a new line of attack for these types of infections. Other types of antibiotics may be used at the same time as treatment with daptomycin, if necessary.

To make sure the bacteria causing an infection are susceptible to daptomycin your doctor may take a tissue sample, for example a swab from the skin, or a blood sample.

Daptomycin is given by a drip into a vein (intravenous infusion) over 30 minutes.

What is it used for?

• Complicated bacterial infections of skin and soft tissue.
• Inflammation of the lining of the right side of the heart and heart valves due to infection with Staphyloccocus aureus bacteria (right-sided infective endocarditis).
• Blood infections with Staphyloccocus aureus bacteria (bacteraemia) that are associated with one of the above infections.

Warning!

• Your kidney function and the amount of creatinine phosphokinase (CPK) in your blood should be monitored before starting treatment and regularly throughout treatment with this medicine.
• Tell your doctor immediately if you experience any muscular symptoms such as pain, tenderness, cramps, or weakness while being treated this medicine, particularly if it is accompanied by a fever or feeling generally unwell. Your doctor may need to check for side effects on the muscles by taking a blood test to measure the level of a compound called creatinine phosphokinase (CPK) in your blood.
• Let your doctor know if you experience any abnormal sensations in your feet and/or hands during treatment with this medicine, for example, numbness, tingling or burning sensations or pain, as this could be indicative of a nerve problem called peripheral neuropathy.
• Antibiotics can sometimes cause inflammation of the bowel (colitis). For this reason, if you get diarrhoea that becomes severe or persistent or contains blood or mucus, either during or after treatment with this medicine, you should consult your doctor immediately.

Use with caution in

• Elderly people.
• Severely decreased liver function.
• Decreased kidney function.
• Severely obese people.
• People taking medicines that can have side effects on the muscles, such as statins or fibrates.

Not to be used in

• Breastfeeding.
• This medicine is not recommended for children and adolescents under 18 years of age, as there is no information regarding its safety and efficacy in this age group.

This medicine should not be used if you are allergic to one or any of its ingredients. Please inform your doctor or pharmacist if you have previously experienced such an allergy.

If you feel you have experienced an allergic reaction, stop using this medicine and inform your doctor or pharmacist immediately.

Pregnancy and breastfeeding

Certain medicines should not be used during pregnancy or breastfeeding. However, other medicines may be safely used in pregnancy or breastfeeding providing the benefits to the mother outweigh the risks to the unborn baby. Always inform your doctor if you are pregnant or planning a pregnancy, before using any medicine.

• The safety of this medicine for use during pregnancy has not been established. It should therefore be used with caution during pregnancy, and only if the benefits to the mother outweigh any potential risks to the developing baby. Seek medical advice from your doctor.
• It is not known whether this medicine passes into breast milk. Mothers who need treatment with this medicine should not breastfeed. Seek medical advice from your doctor.

Side effects

Medicines and their possible side effects can affect individual people in different ways. The following are some of the side effects that are known to be associated with this medicine. Just because a side effect is stated here does not mean that all people using this medicine will experience that or any side effect.

• Headache.
• Disturbances of the gut such as nausea, vomiting, diarrhoea, constipation, indigestion or abdominal pain.
• Pain, redness or itching at the infusion site.
• Rash.
• Fungal infections, such as thrush.
• Elevated levels of liver enzymes and creatine phosphokinase (CPK).
• Urinary tract infection.
• Blood disorders such as anaemia, thrombocythaemia.
• Loss of appetite.
• Anxiety.
• Difficulty sleeping (insomnia).
• Pins and needles (paraesthesia, see also warning above).
• Dizziness.
• Alteration in taste.
• Fatigue, weakness or loss of strength (asthenia).
• Changes in heart rhythm or blood pressure.
• Jaundice.
• Muscle pain, inflammation, weakness (see warning above).
• Kidney problems.
• Joint pain (arthralgia).

The side effects listed above may not include all of the side effects reported by the medicine's manufacturer.

For more information about any other possible risks associated with this medicine, please read the information provided with the medicine or consult your doctor or pharmacist.

How can this medicine affect other medicines?

It is important to tell your doctor or pharmacist what medicines you are already taking, including those bought without a prescription and herbal medicines, before you start treatment with this medicine. Similarly, check with your doctor or pharmacist before taking any new medicines while being treated with this one, to ensure that the combination is safe.

There may be an increased risk of side effects on the muscles (myopathy) if daptomycin is used in combination with any of the following medicines:

• ciclosporin
• fibrates for lowering cholesterol, eg bezafibrate, gemfibrozil
• statins for lowering cholesterol, eg simvastatin, rosuvastatin.

The manufacturer recommends that, if possible, the medicines above should be temporarily stopped during treatment with daptomycin. If these medicines cannot be stopped, CPK should be monitored more frequently and patients should be closely monitored for possible signs of side effects on the muscles.

The following medicines can sometimes affect kidney function and so may affect the removal of daptomycin from the body by the kidneys. These medicines should be used with caution in combination with daptomycin:

• non-steroidal anti-inflammatory drugs (NSAIDs),eg ibuprofen diclofenac, flurbiprofen
• selective inhibitors of COX-2, eg celecoxib or etoricoxib.

If you are taking an anticoagulant medicine to prevent blood clots, for example warfarin, your doctor should be aware that daptomycin can sometimes interfere with laboratory tests that measure your blood clotting time (INR or prothrombin time). Daptomycin may suggest that your INR is higher than it actually is. As a result, any adjustments to the dose of your anticoagulant should only be made after taking this into account. If you are having tests to check your blood clotting time it is best that the blood sample is taken just before your daptomycin dose is given, as this is when the level of daptomycin in your blood is at its lowest.

Other medicines containing the same active ingredient

There are currently no other medicines available in the UK that contain daptomycin as the active ingredient.