The FDA and GlaxoSmithKline are warning health care professionals about the risks associated with improper use of the flu drug Relenza, following the death of a pregnant woman who was administered the drug by mechanical ventilator for three days.
Letters dated October 8, 2009, were sent to healthcare providers warning that Relenza Inhalation Powder (zanamivir) is not intended to be used in a nebulizer or mechanical ventilator. Nebulization of Relenza has not been approved by the FDA, and the drug maker and regulatory agency caution that Relenza Inhalation Powder should only be used as directed, with the Diskhaler device provided with the drug.
Relenza is a popular treatment for influenza, approved for use in patients 7 years of age and older, who have shown flu symptoms for less than 48 hours. The inhalation powder is supposed to be mixed with a lactose sugar for use with the Diskhaler, but the FDA indicates GlaxoSmithKline is aware that some doctors are dissolving the drug in various solutions for the purpose of nebulizing Relenza for patients who are unable to take oral drugs or inhale the medication using the Diskhaler.
The Relenza death that led to the new warning occurred outside the United States, with a pregnant woman who received a solution made from dry powder Relenza via nebulizer for three days. An obstruction in the ventilator that appeared to cause the death, is believed to be due to the stickiness caused by the lactose sugar from Relenza in the nebulizing solution.
The FDA and GlaxoSmithKline warn that Relenza is not designed or intended for nebulization and the lactose sugar can obstruct the proper functioning of mechanical ventilator equipment.