News and Educations

Dear Healthcare Professional Letter to physicians with important information concerning administration, and thereby safe use, of RELENZA (zanamivir)


In cooperation with the Agency for Medicinal Products and Medical Devices, GlaxoSmithKline (GSK) sent a Dear healthcare professional letter to prescribing physicians with important information relating to the administration, and thereby the safe use, of the medicinal product Relenza (zanamivir).

GlaxoSmithKline (GSK) received a report of the death of a patient with influenza, outside Croatia, who received Relenza (zanamivir) Inhalation Powder dissolved and administered by a mechanical ventilator. The Relenza Inhalation Powder was being removed from its original approved packaging and dissolved in various solutions for the purpose of nebulising (atomising) zanamivir, for inhalation by those patients with influenza who had been unable to take oral medication or inhale Relenza inhalation powder by using a Diskhaler (drug administration device).

  • Relenza (zanamivir) Inhalation Powder is not intended to be reconstituted in any liquid formulation and is not recommended for use in any nebuliser or mechanical ventilator.
  • Relenza or zanamivir are not approved for nebulisation by any regulatory authority, and the safety, effectiveness and stability of zanamivir used by nebulisation has not been established.

The Agency for Medicinal Products and Medical Devices will continue to monitor the safe use of this medicinal product. Any information, recommendation and forms related to enhanced monitoring during the pandemic of influenza A/H1N1 can be found at the Agency website.

The full text of the letter can be found below:
"Important medicinal product warning: RELENZA (zanamivir) Inhalation Powder must not be used in a nebuliser"

Summary of Product Characteristics and Patient Information Leaflet are enclosed with the letter to physicians.