The Food and Drug Administration (FDA) and GlaxoSmithKline warned doctors about the proper use of the antiviral drug Relenza after a report of a death caused by receiving the drug through mechanical ventilator was released.

Glaxo wrote to health-care professionals in a letter posted on FDA’s website that it knew about Relenza being removed from its FDA-approved packing and dissolved various solutions for the purposes of administering the drug to patients who can’t take medications orally or by inhaling.

Glaxo informed that they are not planning to reconstitute Relenza in any liquid formulation and is not recommended for use in any nebulizer or mechanical ventilator.

The drug is approved for treating influenza in patients aged 7 and above who have beeen displaying symptoms for less than 48 hours.

The company told that the death was caused outside U. S. and was of a pregnant woman who was on mechanical ventilation. She was given a solution through nebulizer made from Relenza for three days but the death was blamed on obstruction of the ventilator.

Glaxo said that the physician doing the treatment beleived that the obstruction was caused due to stickiness caused by lactose, which is a part of Relenza formulation.

"There is a risk that the lactose sugar in this formulation can obstruct proper functioning of mechanical ventilator equipment," Glaxo said in the letter.