U.S. regulators and Roche Holding AG have warned doctors of psychiatric events, some of which resulted in death, seen in patients taking the flu drug Tamiflu, regulators said on Tuesday.

Drugmaker Roche wrote a letter, dated February 2008, to health professionals advising them of a recent update to the drug's label, according to the Food and Drug Administration.

The revised label includes new information on delirium and other abnormal behavior, some resulting in fatal outcomes, the letter said.

The revisions follow a November 2007 meeting of an FDA advisory panel on the events, which have been seen mostly in Japan.