LONDON, June 9 (Reuters) - British health regulators will update safety advice on GlaxoSmithKline Plc's (London:GSK.L - News) controversial antidepressant Seroxat on Tuesday, sources familiar with the situation said.

ADVERTISEMENT

The new guidelines on the top seller, which belongs to the same class of SSRIs (Selective Serotonin Reuptake Inhibitors) as Eli Lilly & Co's (NYSE:LLY - News) Prozac, will focus on potential side effect problems among under-18s, the sources added.

"We can confirm that we have been in discussions with the regulatory authorities regarding updates to Seroxat labelling," said GSK spokesman David Mawdsley. "However, it's not appropriate to discuss further until we have seen the outcome."

Seroxat, known as Paxil in the United States, has been the subject of increased public concern recently following reports of suicidal tendencies in some users. Other patients have reported severe withdrawal reactions when they stop taking it.

The UK set up a panel to review the safety of Seroxat and other SSRIs in the light of the widespread worries, which were highlighted in two high-profile BBC television Panaroma programmes.

Alison Langley, spokeswoman for the Medicines and Healthcare products Regulatory Authority (MHRA), said a media briefing would be held on Tuesday to outline new advice for patients and prescribers on an unnamed antidrepessant drug.

The meeting will be hosted by Alasdair Breckenbridge, chairman of the MHRA, but Langley declined to give further details.

GSK, which generated global sales of 2.06 billion pounds ($3.40 billion) from Seroxat/Paxil in 2002, insists the medicine is safe and effective.

Although the drug is not officially approved for use among under-18s in Britain, doctors have the discretion to prescribe it to young people on a so-called "off-label" basis.

Two years ago, a Wyoming jury in the United States awarded $6.4 million to the family of a patient taking the drug who murdered his wife, daughter and granddaughter and then committed suicide in what the family said was a reaction to the drug. GSK denies the connection.