Nephrotoxicity has been reported; use with caution in patients with pre-existing renal disease or geriatric patients; dosage adjustments may be required. Respiratory arrest has been reported with use; impaired renal function may increase the risk for neuromuscular blockade and apnea.
Transient, reversible neurological disturbances (e.g., dizziness, numbness, paresthesia, tingling, and vertigo) may occur; patients should be warned that the drug may impair their ability to perform hazardous activities requiring mental alertness or physical coordination (e.g., operating machinery, driving a motor vehicle).
Prolonged use may result in fungal or bacterial super-infection, including C. difficile-associated diarrhea (CDAD) and pseudomembranous colitis.
If colistimethate sodium is administered via a nebulizer, the solution should be used promptly after being mixed. Premixing colistimethate sodium into an aqueous solution and storing it for longer than 24 hours results in increased concentrations of colistin in the solution and increases the potential for lung toxicity if the premixed solution is administered via nebulization. Adults and children who receive colistimethate sodium by oral inhalation via nebulization may be at risk of bronchoconstriction. Premedication with bronchodilators may reduce the potential for development of bronchoconstriction in patients receiving the drug by nebulization. The healthcare providers who choose to prescribe colistimethate sodium for administration by oral inhalation via nebulization should be familiar with the chemistry of the drug and aware of the potential for serious and life-threatening side effects from inhalation of premixed, ready-to use liquid preparations of the drug.