Risky drug keeps approval

Sunday, July 6, 1997
TORONTO (CP) Health Canada has rejected calls to withdraw the
controversial heart drug nifedipine, despite studies indicating it can
cause fatal heart attacks and strokes in some patients.
The department's healthprotection branch accepted an advisory
committee's recommendation that the medication is safe if used properly,
The Globe and Mail reported yesterday.
Shortacting nifedipine is a capsule that patients take three
times a day to relieve angina, the chest pain associated with heart
trouble.
"When used in the right way, there's not a problem," Ellen Burgess
of Calgary's Foothills Hospital, who chaired the committee, told the
newspaper.
But recent articles in medical journals have linked the drug to
fatal heart attacks, cancer and bleeding from the stomach and intestinal
tract, even when given for angina.
Several medical experts in Canada and the United States have said
there is an urgent need for regulators in both countries to err on the
side of caution by withdrawing the drug.
At least 11 people have died in the United States because of the
negative side effects of taking nifedipine, said Dr. Franz Messerli of
Louisiana's Tulane University.
Those are only the deaths he knows about, said Messerli, who
reported some of the deaths in an article in the Journal of American
Medicine.
Dr. Michelle BrillEdwards, a drug safety reviewer for Health
Canada until she resigned last year, said she quit to protest the
department's handling of warnings.
At the time, she said concerns about nifedipine's safety were
expressed as early as 1981, but the department failed to act.
Despite the medical debate, a June 25 letter from Health Canada
tells doctors they can continue using nifedipine and other calcium
channelblockers.
Nifedipine is sold in Canada and the U.S. by Bayer Inc. under the
trademark Adalat. It is also sold in the U.S. by Pfizer Inc. as Procardia
and is available in generic forms.
In the U.S., the FDA responded to concerns in medical literature
by requiring Bayer to add to its labels warnings to doctors not to use the
shortacting drug for the acute reduction of blood pressure, control of
hypertension, or for patients at risk of heart attack.