Medicines used to treat epilepsy and psychiatric disorders may raise the risk of suicidal thoughts and behavior, U.S. Food and Drug Administration warned Thursday.

The angency analyzed 199 studies of 11 epilepsy drugs including Pfizer Inc.'s Neurontin, Novartis AG's Tegretol and Abbott Laboratories' Depakote

It found that of the 44,000 patients in the study -- 28,000 people taking the drugs and 16,000 the placebos, those who took the drugs had about twice the risk of suicidal behavior compared with those who took a placebo.

About 0.4 percent of patients given the drugs reported suicidal thoughts or actions, compared with 0.2 percent of placebo patients, the FDA said.

This means for every 1,000 patients, about two more drug-treated patients experienced suicidal thoughts.

"We have just come to the conclusion that it's time to alert heath-care providers," said FDA spokeswoman Sandy Walsh.

FDA said that the increased risk of suicidality is expected to be present in all antiepileptic drugs, so it would work with drug companies to make sure the latest data is reflected in their prescribing information and labeling.

(Agencies via Xinhua News Agency February 1, 2008)