The U.S. Food and Drug Administration (FDA) has reported that a person with influenza died after receiving zanamivir inhalation powder, a flu medicine marketed as Relenza®, that was dissolved and administered via a nebulizer.

Zanamivir is only approved for use with the Diskhaler device that is provided in the package with the flu medicine. Relenza is not designed or intended to be administered by nebulization.

GlaxoSmithKline, the manufacturer of Relenza, learned that the flu medicine was being dissolved in various solutions so that it could be inhaled by sick patients who were unable to take oral flu medicine or use the Diskhaler provided with the drug. According to the FDA, there is a risk that the lactose sugar used in the formulation of this flu medicine can interfere with the proper functional of mechanical ventilator equipment. The reported death occurred outside of the United States, and the patient was a pregnant woman on a ventilator who received the nebulized flu medicine solution for 3 days.
 

Source:

U.S. Food and Drug Administration MedWatch, posted October 9, 2009.