Updated

Children who take a common drug for attention deficit disorder should be warned about the risk of suicidal thoughts, U.S. pediatric health advisers said on Monday.

Several members of an advisory committee to the Food and Drug Administration asked the agency to change the label for Focalin, an attention deficit medicine made by Swiss drugmaker Novartis AG, to reflect this risk. The drug is approved for children aged 6 or older.

The FDA often follows the advice of its committees, although it is not required to.

The FDA said it received eight reports of suicidal thoughts for children or adolescents who took the drug over the past six years, and four of the cases appeared to be linked to the medicine. The link for the remaining cases was less clear.

"The suicidal ideation seems to be pretty serious," said Dr. Sheldon Kaplan, panel member and chief of infectious diseases at Texas Children's Hospital.

But the FDA said the risk of suicidal thoughts did not appear in clinical trials for Focalin, and the later reports were a tiny number compared to how many children used the drug.

"I'm somewhat puzzled by the focus of suicidal ideation," said Tom Laughren, head of the FDA's psychiatric products division, in response to the panel's recommendation.

"These drugs are very widely used. And what you're seeing here are a handful of reports that are difficult to interpret with regard to causality," he said.

The number of children diagnosed with attention deficit hyperactivity disorder (ADHD) has skyrocketed in recent years, with the condition now affecting 3 to 5 percent of kids globally.

Children with ADHD are excessively restless, impulsive and easily distracted, and often have trouble at home and in school. There is no cure, but the symptoms can be kept in check by a combination of behavioral therapy and medication.

In the United States, some 2.7 million people have prescriptions for ADHD drugs including Novartis' Ritalin, Johnson & Johnson's Concerta, Shire's Adderall and Vyvanse and Eli Lilly's Strattera.

Some patient advocates say doctors and parents may be too quick to diagnose kids with the condition, and the drugs may cause side effects that can damage children's health.

The FDA said about 1.8 million children received prescriptions for Focalin or its generic versions from May 2005 to July 2011.

The label for Focalin already warns patients that they may have new psychotic or manic symptoms after taking the drug, but does not mention suicidal thoughts.

Out of other ADHD drugs, only Strattera's label mentions thoughts of suicide as a side effect, as part of a restrictive "black box" warning.

The FDA monitors reports of side effects from medicines after they've been approved in order to discover potential safety problems. For drugs that are used by children, the agency must hold regular advisory meetings to review their safety.

The advisory committee and FDA reviewers also recommended a change to Focalin's label to reflect the risk of anaphylaxis, an allergic reaction, and angioedema, a type of swelling beneath the skin.

Novartis said it is will make any necessary changes to Focalin's label after discussing them with the FDA.

"Novartis is committed to patient safety and will continue to work closely with the FDA as the agency completes its review," said Brandi Robinson, spokeswoman for the company.