Use of intravenous zanamivir after development of oseltamivir resistance in a critically Ill immunosuppressed child infected with 2009 pandemic influenza A (H1N1) virus.

Immunosuppressed patients receiving oseltamivir for 2009 novel H1N1 influenza A infection may develop drug resistance, leading to treatment failure. Intravenous zanamivir was administered on a compassionate-use basis to a profoundly immunosuppressed pediatric patient with severe oseltamivir-resistant novel H1N1 pneumonia. The regimen was well tolerated and was associated with a decrease in viral burden.