According to MIMS (November 2013), the costs of preparations of colistimethate sodium for inhalation (excluding VAT) are as follows:
Colobreathe costs £968.80 for 56 capsules containing 1.6625 million units and a Turbospin inhaler.
Colomycin injection costs £18.00 for 10 vials containing 1 million units of colistimethate sodium and £32.00 for 10 vials containing 2 million units of colistimethate sodium.
Promixin costs £138.00 for 30 vials containing 1 million units of colistimethate sodium. The price includes the cost of the nebuliser, training, support service and all related consumables.
The costs of these preparations are difficult to compare directly. Colomycin injection and Promixin are administered using a nebuliser, whereas Colobreathe is administered using a dry powder inhaler. In the case series summarised here, colistimethate sodium was nebulised. The price of Promixin includes the cost of the nebuliser, training, support service and all related consumables, whereas that for Colomycin injection does not. Also, the optimal dose of colistimethate sodium for non-cystic fibrosis bronchiectasis is unclear. Colistimethate sodium was given at a dose of 2 million units twice daily in White et al. (2012), 1–2 million units twice daily in Dhar et al. (2010) and Berlana et al. (2011), and 30 mg daily (estimated to be around 375,000 units) in Steinfort and Steinfort (2007). It is often unclear which preparations were used.
The Prescription Cost Analysis for England shows that in 2012 11,700 prescription items were dispensed for Promixin (1 million units) at a net ingredient cost of £3,159,400. For Colomycin injection, 23,100 prescription items were dispensed for the vials containing 1 million units, at a net ingredient cost of £2,461,800; 13,200 items were dispensed for the vials containing 2 million units at a cost of £2,427,300. Colomycin injection can be given by intravenous infusion, as well as nebulisation. No information is provided on the proportion used via each route
It is not known what indications these preparations were prescribed for.