Canada suspends sales of Shire’s Adderall XRCanadian regulators last night suspended the sales of Shire's attention deficit hyperactivity disorder drug Adderall XR in Canada, citing a risk it may cause sudden deaths.
Shire sold $759 million of Adderall in the U.S. in 2004 and $10 million in Canada.
A senior FDA official told the Wall Street Journal, the agency has examined the same data as Canadian regulators and "We do not believe it is strong enough at the moment to merit an immediate change to the labeling or marketing status here in the United States."
Overall, he said, the rate of sudden deaths and cardiovascular problems among the patients taking the withdrawn drug "doesn't appear significantly different from the rate of other similar drugs" used for the condition, or "from the background rate for people of the same age groups who are not taking these products."
In a one-page letter to Shire, Health Canada said the identified risk of sudden death following the recommended doses cannot be managed by label changes.
Shire said there have been 20 reports of sudden death on Adderall's extended release and a prior formulation of the drug since 1994, when the drug first entered the market.
Many of these deaths occurred in patients who had serious cardiac abnormalities. In other cases the company lacked sufficient information to determine if the patients' hearts were normal or defective.
"The sudden deaths were extremely rare," a Shire spokesman told the Journal.
More than 38 million prescriptions for the new and old versions of the drug have been written during that time.
Shire chief executive Matthew Emmens said in a company statement, "We are surprised by this action from Health Canada."
Emmens received a call from Health Canada late in the day seeking a voluntary withdrawal of the drug. He told the Journal he refused to pull the drug and Health Canada responded by suspending it indefinitely.
Shire said in a statement it remains confident in the safety and effectiveness of the drug for the treatment of ADHD when used in accordance with the approved labeling.