On November 13, 2006, Roche Pharmaceuticals Incorporated and the Food and Drug Administration (FDA) announced that Tamiflu, a drug used to prevent or lesson the severity of the flu, may cause abnormal behavior, including delirium and hallucinations in patients. Tamiflu is prescribed to patients one year and older who have had flu-like symptoms for no more than two days.

The pharmaceutical company updated the drug’s package insert after a 10-month review found more than 100 reported cases of unusual psychiatric behavior. Most cases involved children under 17 years old in Japan, including three people who fell to their deaths after taking the drug. One death involved an adult who left a suicide note.

An FDA memorandum also cited an eight-year-old child who took one dose of Tamiflu and, less than two hours later, tried to run out of the front door. He would not answer to his name and was growling.

67 percent of the reported abnormal behavior cases were in children and 95 percent occurred outside of the United States, mostly in Japan.

While the FDA said there is no established relationship between the drug and the abnormal behavior, it recommended close monitoring for patients immediately after taking the drug.

On November 13, 2006, in a letter to healthcare professionals, Medical Director for Roche Laboratories Dominick Iacuzio wrote that cases of psychiatric side effects from Tamiflu are rare.

Japan is Tamiflu’s biggest consumer, with 24.5 million prescriptions filled from 2001 to 2005. In the United States, there were 6.5 million prescriptions filled during the same period.

Sources: Healthcare Provider Label Update, Roche Laboratories, November 13, 2006; Patricia Kowsmann, “FDA urges caution on flu drug,” Wall Street Journal, November 14, 2006; Jia-Rui Chong, “Tamiflu linked to abnormal behavior,” Los Angeles Times, November 14, 2006; “Tamiflu patients should be monitored, FDA says,” Los Angeles Times and the Associate Press, November 14, 2006.