An FDA review team, recommended last week that precautionary warnings be added to two influenza vaccines, Roche's Tamiflu and GlaxoSmithKline's Relenza, noting possible neuropsychiatric side effects in children.
"While there have not been noticeable changes in the types or pattern of neuropsychiatric adverse events reported in association with the use of Tamiflu, the number of cases continued to increase," the advisory team stated in a report.
"Regardless of whether they represent a drug-class adverse event, a drug–disease interaction, or a disease manifestation, healthcare providers should be aware of neuropsychiatric events and parents should be instructed to monitor their children closely when beginning medication for influenza."
Both Roche and GlaxoSmithKline stated that they would work with FDA to identify the problem, and clinical and nonclinical trials are being conducted.
On Tuesday, GSK presented safety information on Relenza to the FDA's Pediatric Advisory Committee showing no conclusive evidence of a causal association between Relenza and neuropsychiatric events.
"GSK believes the current Relenza US prescribing information accurately reflects the safety profile of the drug," GSK spokesperson Jeff McLaughlin wrote to Pharm Exec in an e-mail on Thurdsay. "The committee acknowledged that there are neuropsychiatric complications associated with influenza infection and that information should be communicated to healthcare providers. We expect to discuss the committee's decision with FDA and ensure that all information is updated, as appropriate."
The report notes that there have been 25 deaths reported in patients under 21 receiving Tamiflu. Only three were in the United States. Side effects have been reported more heavily in Japan, a country that is far more proactive in giving influenza vaccines. No deaths have been reported involving Relenza.