WASHINGTON ~ The drug Tamiflu now carries a new warning following reports of delirium among some people, mostly in Japan, taking the medication to treat influenza, the manufacturer and US regulators announced.

The notification to doctors from the US Food and Drug Administration (FDA), which regulates medicine, and the Swiss pharmaceuticals giant Roche, which manufactures Tamiflu, also used to fight the deadly strain of bird flu, was reported on the FDA website on Monday.

The antiviral drug’s “precautions section” notes that “there have been post-marketing reports (mostly from Japan) of self-injury and delirium with the use of Tamiflu in patients with influenza,” according to a copy posted on the FDA site.