Promixin® (colistimethate) one-million-unit powder for nebuliser solution unit dose vials (UDVs) is being discontinued from early May 2025, with stocks anticipated to be exhausted by this date.

Switching from Promixin® to alternative colistimethate preparations should be carried out under specialist supervision as products vary in indications, dosing and administration. Ensure patients understand how to use the new nebuliser device to administer the correct dose.

Actions to be completed by Wednesday 30 April 

Primary and secondary care providers

1. Do not initiate new patients on Promixin® one-million-unit powder for nebuliser solution UDVs. 
2. Pro-actively identify and review all patients currently prescribed Promixin® one-million-unit powder for nebuliser solution UDVs and immediately refer them to their respiratory specialist to switch to an alternative colistimethate preparation.

Respiratory specialists within secondary care should consider the patients diagnosis and

1. Consider prescribing Colicym® one-million-unit powder for nebuliser solution unit dose vials.
2. Where the above is not suitable, prescribe Colomycin® one-million or two-million-unit powder for solution for injection, infusion or inhalation.
3. When switching colistimethate products, ensure patients are provided with appropriate education and training to ensure they can use the new nebuliser device and administer the correct dose.
4. Once switched to an alternative colistimethate product, clinicians in secondary care should ensure this is documented and shared with primary care, for ongoing treatment, where applicable.

Note the following

• Colicym® is only licensed for nebulisation. Not available for prescribing and dispensing in primary care. Supply available from hospital only. 
• Colomycin® one-million and one-million unit powder for solution is licensed for administration via both the intravenous and inhaled route and are in limited supply until at least early May and mid-April respectively and unable to support an increase in demand during this period. Current stock to be reserved for existing patients. Can be prescribed in primary care and supply obtained and dispensed by community pharmacies.  
• Care should be taken to ensure the correct product has been selected when dispensing and administering colistimethate products.

Refer to the SPS Medicines Supply Tool (registration and login required) for the latest information on Colomycin® stock availability.

Full information regarding the National Patient Safety Alert is also available.