February 9, 2005

Dear Health Care Professional,

Health Canada advises you that marketing of the Attention Deficit Hyperactivity Disorder (ADHD) drug, ADDERALL XR^TM (amphetamine salts) has been suspended effective February 9, 2005. ADDERALL XR^TM, marketed by Shire BioChem Inc., is a prescription drug that was authorized in Canada for the treatment of Attention Deficit Hyperactivity Disorder (ADHD) in children.

Health Canada's decision to withdraw ADDERALL XR^TM is founded on very rare, international, spontaneous reports of sudden deaths, in paediatric and adult patients in association with ADDERALL^® (immediate release) and ADDERALL XR^TM (extended release). Reports for death include those for patients taking usual recommended doses, including recommended starting doses, of ADDERALL^® and ADDERALL XR^TM. In a minority of cases, the events occurred on the first day of dosing or shortly after an increase in dose or a switch from another drug in the structural class. Deaths were reported for patients both naïve or chronically exposed to amphetamine-related Central Nervous System stimulants. This decision was not based on reported deaths that were associated with overdose, misuse or abuse. Of the 20 reported deaths, there were cases that occurred in patients without a documented history of structural or other cardiac abnormalities/disease. In a few cases, other drugs, including anti-depressants, clonidine and/or anti-psychotics, were concomitant medications. Exercise was an associated event in some of the reports of death. None of the reported deaths occurred in Canada.

Health Canada is aware of 20 international reports of sudden death in patients taking either ADDERALL^® (immediate release) or ADDERALL XR^TM (extended release) with 3.45 million patient-years of exposure. 14 deaths occurred in children, and 6 deaths in adults. ADDERALL XR^TM has been marketed in Canada since January 23, 2004, while the immediate release form of ADDERALL^® has never been marketed in Canada.

A preliminary review of safety data for the other stimulants authorized for use in the treatment of ADHD in Canada has been conducted. The incidence of serious adverse reactions leading to death was higher in ADDERALL^®/ADDERALL XR^TM than in the other stimulants, based upon these reviews. In addition, the safety information submitted to Health Canada also included 12 reported cases of stroke, with 2 occurring in children.

Health Canada has requested manufacturers of other stimulants approved for the treatment of ADHD provide a thorough review of their worldwide safety data. Information updates will be provided as they become available.

Health Canada reminds physicians of the following wording currently contained in Product Monographs of all drugs indicated for the management of ADHD: "[X] is indicated as an integral part of a total treatment program for ADHD that may include other measures (psychological, educational, social) for patients with this syndrome. Drug treatment may not be indicated for all patients with this syndrome. Drug treatment is not intended for use in the patient who exhibits symptoms secondary to environmental factors and/or other primary psychiatric disorders, including psychosis. Appropriate educational placement is essential in children and adolescents with this diagnosis and psychosocial intervention is often helpful. When remedial measures alone are insufficient, the decision to prescribe drug treatment medication will depend upon the physician's assessment of the chronicity and severity of the patient's symptoms."

The identification, characterization, and management of marketed health product-related adverse reactions are dependent on the active participation of health care professionals in adverse reaction reporting programmes. Any occurrences of cardiac or other serious and/or unexpected adverse reactions in patients receiving ADHD treatments should be reported to Health Canada at the following address: