New York State's attorney general Eliot Spitzer said Wednesday he was suing U.K.-based

GlaxoSmithKline

(GSK) - Get Report

for allegedly concealing information about the antidepressant drug Paxil.

The lawsuit, filed in New York State Supreme Court in Manhattan, accused the company of "repeated and persistent fraud" by "concealing and failing to disclose" information about Paxil to doctors, according to a statement issued by Spitzer's office. The lawsuit alleges that the company, starting in 1998, concealed and misrepresented information about Paxil's impact on children.

Paxil hasn't been approved by the Food and Drug Administration for children. That prevents the company from marketing the drug as a treatment for children; but federal law still allows doctors to prescribe the drug for children. This 'off-label use' practice applies to any drug approved by the FDA.

GlaxoSmithKline responded by saying the company has "publicly communicated data" from all studies involving children. "All pediatric studies have been made available to the FDA and regulatory agencies worldwide," the company said.

In afternoon trading, the company's stock was down $1.43, or 3.3%, to $41.34.

Spitzer contended that GlaxoSmithKline only published one of at least five Paxil studies related to children. He also cited an internal company document from 1999, quoting an unidentified employee as writing that GlaxoSmithKline wanted to control the dissemination of test data "to minimize any potential negative commercial impact."

GlaxoSmithKline said Wednesday that this internal memo -- which it identified as having been written in 1998 -- "is inconsistent with the facts and does not reflect the company position."

The use of antidepressants in children has become a hot topic in court and among regulators. In March, the FDA issued a public health advisory -- which followed advisories of October 2003 and June 2003 -- about antidepressants and children. After reviewing reports on 10 drugs, including Paxil, the agency said "it is not yet clear whether antidepressants contribute to the emergence of suicidal thinking and behavior."

However, the agency said it was asking manufacturers to change their drugs' labels to include "stronger cautions and warnings" about the need to monitor patients whose depression worsens or who talk about suicide.

Among anti-depressants, only Prozac is approved for children and adolescents for a condition called pediatric major depressive disorder. Zoloft and Prozac have been approved by the agency for treating obsessive-compulsive disorders in children.