Glaxo adds warnings of reported seizures, psychiatric problems to flu drug Relenza

Under pressure from regulators, drugmaker GlaxoSmithKline has added warnings of reported psychiatric problems to the label for its flu drug Relenza.

The new language lists seizures, hallucinations and delirium as among the problems seen in patients taking the drug. The Food and Drug Administration highlighted the changes Wednesday in a posting to its Web site.

Most problems occurred in Japanese children taking the drug. Japan is the largest market in the world for flu medications because doctors there prescribe drugs like Relenza as a standard treatment for flu symptoms.

The new Relenza label stresses that there is no causal link between Relenza and the psychiatric problems.

London-based Glaxo alerted doctors to the changes in a letter last month, which the FDA posted to its Web site.

Swiss drug maker Roche made similar changes to the label for its drug Tamiflu last month. Tamiflu was the top-selling flu medication worldwide last year with sales of $2.4 billion.

Relenza had sales of $520 million.

Shares of GlaxoSmithKline rose 31 cents Wednesday to $44.51.