Tamiflu Not for Young Infants, Roche Says
Roche Laboratories Inc., the maker of the oseltamivir phosphate product Tamiflu, warned health care providers in December that the antiviral drug could be hazardous to children under 1 year of age and must not be used in this population.
The warning reflects concerns that infants might be administered the drug to treat influenza symptoms during the current national shortage of influenza vaccinea shortage made worse by an influenza season that began early and seems to be hitting children hard.
According to the product's current Food and Drug Administration (FDA)-approved labeling, Oseltamivir is indicated for the treatment of uncomplicated acute illness due to influenza infection in patients age 1 year or older who have been symptomatic for no more than two days.
Roche stated in a "Dear Health Care Professional" (PDF) letter that, in studies of rats, oseltamivir appeared to easily cross the permeable blood-brain barrier of newborns and may cause death. In studies involving very high dosages of the drug, brain levels of oseltamivir phosphate in seven-day-old rats were "approximately 1500 times" the typical level in the adult animals.
The one-year minimum age for oseltamivir in humans is based on data suggesting that the human blood-brain barrier has matured by that age.