Why is this medication prescribed?
Colistimethate, or colistin, belongs to a class of antibiotics called polymyxins. It is used to treat or prevent bacterial infections. It can be given by inhalation to decrease the amount of bacteria (Pseudomonas aeruginosa) in the airways. It can also be given intravenously to treat acute lung infections. The main goal is to improve or maintain lung function.
How does this medication work?
Colistin is given by inhalation to decrease the amount of bacteria (Pseudomonas aeruginosa) in the lungs.
What is the usual dose?
Colistin is available as a powder in a vial that can be stored at room temperature. The usual dose for adults with CF is 75mg twice a day via nebulizer.
How should this medication be taken?
Take inhaled colistin at approximately the same time everyday so that it is easier to remember. Also take the doses as close to 12 hours apart as possible.
To mix your daily dose of colistin:
1. Remove the lid from the colistin vial.
2. Remove the lids from the sterile water and saline vials.
3. Swab the rubber top of all vials with an alcohol swab before inserting the syringe.
4. Draw up 2mL of sterile water for injection into a syringe (always use a new syringe with each treatment preparation).
5. Inject 2mL of sterile water into the colistin vial, while gently rotating and swirling the bottle (to prevent foaming) until all the white powder has dissolved. DO NOT shake vigorously.
6. Withdraw 1mL (75mg) of the colistin and place it into the nebulizer.
7. Draw up 2mL of normal saline and add into the nebulizer.
8. Place the remaining mixed colistin (1mL) into the refrigerator for future use.
9. Discard unused portion after 24 hrs.
After mixing your own colistin use it within 24 hours. We recommend that every day you label your colistin after mixing it in the morning and then discard any left over after your evening dose.
If you are taking other inhaled medication(s), please take them in this order.
Note: DO NOT mix colistin with any other medications. You may use a Bronchodilator such as Ventolin® before taking your inhaled colistin. Remember, DO NOT use any premixed, ready-to-use, or liquid forms of colistin prepared by a pharmacy.
After use, rinse your nebulizer well with warm water to prevent build up that can clog your nebulizer. For further instructions, see Cleaning and Disinfecting Your Equipment.
What should I do if I miss a dose?
Do not double any dose. If you forget to take a dose, take the missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and take the next scheduled dose.
What should I expect from this medication?
You may or may not experience side effects. These side effects may disappear but let your doctor know if they are severe or if they persist for more than 2 days. These can include hoarseness, chest tightness and wheezing but tell us if you have any other side effects as well.
To minimize these side effects, we recommend you use a bronchodilator (like Ventolin®) before taking your inhaled colistin dose.
Do not be alarmed if you see the colistin foaming in your nebulizer, this commonly happens during nebulizer treatment and cannot be prevented.
Remember to tell your doctor if you have ever had a previous reaction to colistin or any inhaled medication in the past.
As well, if you are pregnant or think you may be pregnant discuss this with your CF doctor.