Zanamivir (Relenza) Must Not Be Given by Nebulization

Zanamivir is a neuraminidase inhibitor with activity against influenza viruses, including the 2009 pandemic H1N1 strain. It is FDA approved for influenza treatment (patients aged ≥7 years) and prophylaxis (patients aged ≥5 years) in patients without underlying airway disease and is to be administered using a Diskhaler device. However, the drug is sometimes being removed from its approved packaging, dissolved, and administered by nebulization to individuals who are severely ill and unable to inhale it from the Diskhaler or to take oral oseltamivir.

Now, GlaxoSmithKline and the FDA have issued a Medwatch report describing a fatality — a pregnant woman on mechanical ventilation — thought to have been related to nebulization of zanamivir. The la…