Health Canada Put Adderall Back on the Market Based on "Inconclusive Evidence"

Safety of Adderall Cannot be Adequately Evaluated Says Expert Committee Chairman

In the October 11, 2005 edition of the Canadian Medical Association Journal ("CMAJ"), an article by Wayne Kondro reveals that Health Canada reintroduced Adderall (amphetamine salts) to the Canadian market in August 2005 not because the agency found Adderall to be safe but, rather, because "an independent panel found it impossible to accurately ascertain whether the drug increases the risk of cardiac death."

As some may know, Adderall is a central nervous stimulant used in treating attention-deficit hyperactivity disorder (ADHD).  Adderall was taken off the Canadian market in February 2005 after its manufacturer, Shire Biochem Inc., had  disclosed to drug regulators reports of 20 sudden deaths and 12 strokes worldwide among patients taking the standard formulation of Adderall or its one-a-day formulation Adderall XR -- which was (and is, again) the only version sold in Canada.

Adderall maker Shire had appealed the February 2005 recall decision to  Health Canada , which led to the establishment of an expert committee.  Its members were called upon to to determine the issue of whether Adderall was riskier than other ADHD drug therapies available in Canada.

As Mr. Kondro reports, however, this expert committee did not make any final determination on the Adderall-safety issue:

The committee, chaired by pharmaco-epidemiologist Dr. Mitchell Levine, director of the Centre for Evaluation of Medicines at St. Joseph's Healthcare in Hamilton, Ont., came down squarely on the fence. Levine's panel concluded Health Canada and Shire used different data sets for their risk analysis and that both used methodologically weak analyses, although Health Canada acted properly in withdrawing the drug as a precaution.

It was impossible to prove or disprove that using Adderall increases the risk of sudden cardiac death, stroke, or both, particularly in children, Levine says. Nor was it possible to determine whether Adderall XR "was particularly worse or more harmful."

According to the October 11, 2005 CMAJ article by Kondro, this expert committee did conclude that it is "biologically plausible" that there is an increased risk of adverse events, generally, from using any stimulants to treat ADHD. But -- in light of the uncertainties about whether Adderall was riskier than other ADHD drug therapies -- the committee recommended that Adderall should be returned to the Canadian market with a revised package insert label which warned against the use of Adderall by patients with structural heart abnormalities.

Dr. Levine, the chairman of this expert committee, offers the following advice about Adderall to doctors and patients.  Insofar that, according to Levin and his committee, the safety of Adderall cannot be adequately evaluated, before prescribing Adderall, doctors should consider obtaining a baseline ECG for:

• any patient with a family history of pediatric heart failure,
• any patient who regularly undergoes strenuous exercise, or
• any patient who has congenital abnormalities.

In the summer of 2005 Health Canada adopted the committee's recommendation that Adderall be reintroduced to the market.  The drug's manufacturer Shire has said that adequate supplies of Adderall will be available in Canada sometime in October 2005.

(Posted by: Tom Lamb)