Colomycin injection contains the active ingredient colistimethate sodium, which is a type of medicine known as a polymyxin antibiotic. It is used to treat infections with bacteria. (Colistimethate sodium is also sometimes called colistin sulfomethate sodium.)
Colistimethate works by binding to the cell membrane of bacteria cells. The cell membranes 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. Colistimethate damages the cell membrane and allows holes to appear in the cell walls. This kills the bacteria.
Colistimethate sodium is not absorbed from the gut so can't be taken by mouth to treat systemic infections. It is given by injection into a vein to treat serious infections caused by Gram-negative bacteria, including Pseudomonas aeruginosa, Acinetobacter baumanii and Klebsiella pneumoniae. Colistimethate is only used when other antibiotics are ineffective because the bacteria causing the infection are resistant to other antibiotics.
Colistimethate is given by inhalation to treat Pseudomonas aeruginosa infection of the lungs in people with the lung condition cystic fibrosis. In this case the injection solution is inhaled into the lungs from a machine called a nebuliser. This machine converts the liquid medicine into tiny particles that can be breathed into the lungs. This allows the antibiotic to penetrate the lung secretions and act directly in the area of infection.
This medicine should not be used if you are allergic to 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.
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.
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, it does not mean that all people using this medicine will experience that or any side effect.
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.
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 make sure that the combination is safe.
There may be an increased risk of side effects on the kidneys if this medicine is used in combination with other medicines that can affect kidney function, such as the following:
Colistimethate sodium may oppose the effects of neostigmine and pyridostigmine used to treat the muscular condition myasthenia gravis.
Oral typhoid vaccine (Vivotif) should not be taken until at least three days after you have finished a course of this antibiotic, because the antibiotic could make this vaccine less effective.
Colistimethate injection is also available generically (ie without a brand name).