Shire Says Wants More Study on ADHD Side Effects

LONDON — Shire Pharmaceuticals Group Plc said on Friday it wanted further study to determine if there were possible adverse effects from its drug for treating attention deficit hyperactivity disorder (ADHD) after a U.S. advisory panel said such drugs should carry strong warnings.

The committee narrowly voted on Thursday to recommend the warning even though members agreed it was unclear if the drugs contributed to sudden deaths, heart attacks and other complications.

ADHD drugs include Novartis AG’s Ritalin and Shire’s Adderall.

"While we fully support full disclosure and adequate warning, Shire believes that the interests of physicians and patients would be better served by further study to determine whether there is, in fact, a relationship between these medicines and cardiovascular events," Shire said in a statement.

"Obtaining this information is crucial prior to taking what would be an unprecedented action to include something in a black box that has not been supported by sufficient data."

The Food and Drug Administration will consider the panel’s recommendation for a warning highlighted by a black box, the most serious type for prescription drugs. The committee voted 8-7 in favor of the warning, with one abstention.

Each month doctors write about 1 million prescriptions for ADHD drugs for adults and 2 million for children, FDA reviewers said.

Several panel members said there was reason to worry because the ADHD drugs are amphetamines or chemically similar drugs. Amphetamines are known to raise blood pressure, often a precursor to severe heart problems.

Shire said its Adderall already carries a black box saying misuse of amphetamines may lead to sudden death or serious cardiovascular events and it believes that further action is unwarranted.