- Health Canada has stripped a pharmaceutical company of
the right to sell a popular drug used for the treatment of hyperactive
children in Canada after talks about withdrawing the medication voluntarily
broke down.
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- The highly unusual move -- market authorization has not
been withdrawn from any of the 5,000 prescription drugs on the Canadian
market since 1999 -- came after Shire Biochem Inc. revealed that at least
20 people taking Adderall XR had died suddenly, and 12 others suffered
debilitating strokes. All the deaths and strokes were in the United States.
Most involved children who died of stroke, which occurs when a blood vessel
to the brain is blocked by a blood clot or bursts, cutting off oxygen to
the brain.
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- After a review of the drug's safety data, Health Canada
asked Shire at about 5 p.m. Wednesday to voluntarily withdraw the drug,
said company spokesperson, Matt Cabrey. Shire officials refused,
reiterating
their belief Adderall XR was a safe therapy.
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- Within about an hour, the department told the company
it was suspending sales of the drug used in the treatment of attention
deficit hyperactivity disorder (ADHD) indefinitely, and issued a news
release
to that effect Wednesday evening.
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- "Adverse events are very rare but they are also
catastrophic," Dr. Robert Peterson, director general of the
therapeutic
products directorate at Health Canada, said yesterday in explaining the
move.
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- He said the benefits of the drug, improving attention
span, had to be balanced against the risk, possible death. Given currently
available information and the fact that there are many other ADHD drugs
on the market, the continued sale of Adderall XR could not be justified,
he said.
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- Dr. Peterson said Health Canada is unclear why so many
children taking the drug died suddenly, but decided to err on the side
of caution. The Health Department has also asked all the makers of similar
drugs to submit updated safety information, which will be reviewed.
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- The action, however, angered many clinicians and
patients,
and even the Food and Drug Administration, the U.S. regulator, distanced
itself from the move. The drug's maker, for its part, is threatening legal
action.
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- Pam Eisen, a Toronto-area mother of a severe ADHD
sufferer,
said she is troubled and unsure what she will do if the 14-year-old can
no longer get Adderall. "My son has gone from not being interested
in school at all, and being really disruptive, to being one of the
most-improved
students."
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- Ms. Eisen said David was taking Ritalin for five years
but it was never as effective as Adderall. "I would definitely keep
using it if I could because nothing else has worked."
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- Dr. Umesh Jain, a child and adolescent psychiatrist and
administrator of the Canadian ADD Resource Alliance, also had high praise
for Adderall XR.
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- He said the once-a-day, long-lasting formulation is of
great benefit to patients, particularly to children.
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- Dr. Jain said while he appreciates that Health Canada
is concerned with patient safety, he is angry at the way the decision was
made to withdraw authorization to sell the drug in Canada -- suddenly and
without warning.
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- "What are my patients supposed to do now?"
he wondered. "I have to slot them all in and find alternative
treatments.
But what happens if they don't have supply in the meantime? Do they have
to go through withdrawal?"
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- Dr. Jain, who is also a researcher at the Centre for
Addiction and Mental Health in Toronto, said he takes issue with Health
Canada's interpretation of the safety data. He said among the 20 Adderall
XR users who died suddenly, the vast majority had prior heart problems,
and there is no evidence that children or adults with healthy hearts are
at risk. "If you take out the kids with prior cardiac difficulty,
the difference in risk is negligible," Dr. Jain said.
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- The U.S. FDA said yesterday, that unlike Canada, it will
allow sales of the drug to continue. A spokesman said yesterday that there
is no convincing evidence the Adderall is "clearly responsible"
for these deaths.
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- There were 64,098 prescriptions dispensed for Adderall
in Canada in 2004 (meaning that about 11,000 people are taking the drug),
according to IMS Health Canada, a private company that tracks
prescription-drug
trends. Sales totalled $6.6-million in Adderall's first year on the
market.
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- Adderall makes up only 4 per cent of total prescriptions
for analeptics -- drugs used to treat ADHD and similar conditions. The
great majority of children and adults with the condition take
methylphenidate
-- best known by its brand name Ritalin, though there are many generic
forms. There were 1.7 million prescriptions dispensed for analeptics last
year, with sales exceeding $87.5-million.
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- Health Canada has advised patients taking Adderall XR
to consult a physician about alternative treatment and to return any unused
drugs to a pharmacy.
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