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FDA checks into possibility of epilepsy
drug-suicide link
By Julie Schmit, USA TODAY
The Food and Drug Administration wants 14 drugmakers to check their
study data to see if use of epilepsy drugs results in suicidal
behavior or thoughts.
The FDA requested the reviews last month and gave
the drugmakers six months to respond.
The request is similar to one the FDA made in
2003 regarding antidepressants and suicidal behavior in children. That
review resulted in a "black box" warning, the FDA's toughest, on the
drugs' labels last year. This is only the second review of that type,
says Robert Temple of the FDA's Center for Drug Evaluation and Research.
U.S. sales of anti-seizure drugs, including No.
1-seller Neurontin, made by Pfizer, and No. 2 Topamax from Ortho-McNeil
Pharmaceutical, were the fifth-largest drug category last year, says
research firm IMS Health. That's largely because they're used for many
ailments other than epilepsy, which affects an estimated 2.7 million
Americans. Neurontin is most often prescribed for pain. Topamax also
prevents migraines.
The FDA says it's doing the review because, as it
learned with antidepressants, links between medications and adverse
events can be missed "if you don't look properly," Temple says. The FDA
review was first reported by the Boston Globe Wednesday.
The agency also has been pressed by New York law
firm Finkelstein & Partners. It asked the FDA last year to add a black
box suicide warning to Neurontin and says it has given the FDA 261
reports of people who committed suicide while on Neurontin. None had
attempted suicide before, says attorney Andrew Finkelstein. Half took
Neurontin for pain, he says.
Finkelstein has filed 73 personal injury lawsuits
against Pfizer regarding Neurontin. Finkelstein says FDA drug reviewers
in 1992 — two years before Neurontin hit the market — concluded the
drug's safety profile was good, but that less common, serious adverse
events would limit its usefulness. One concern was that depression in
people with epilepsy might worsen and lead to suicide. The FDA is
reviewing that report, Temple says.
More than 10 million people have taken Neurontin,
Pfizer says. The drug's prescribing information, a 29-page document that
goes to doctors, mentions "suicide gesture" as a rare adverse event,
meaning it occurs in fewer than 1% of 1,000 patients. Pfizer spokesman
Paul Fitzhenry says Neurontin adverse event reports over the past decade
"show no link between Neurontin and suicidal thoughts or behavior."
Last year, Pfizer division Warner-Lambert pleaded
guilty to illegally marketing Neurontin to treat ailments for which it
was not FDA approved. Although the marketing occurred in the mid-1990s,
before Pfizer owned Warner, Pfizer paid $430 million in fines to settle
the Justice Department's allegations.
Neurontin is FDA-approved to treat epilepsy when
used with another drug and for pain related to shingles. But doctors can
prescribe drugs for whatever they want, and prosecutors say the illegal
promotion boosted Neurontin sales so that 94% were for non-FDA approved
conditions by 2002.
Gregory Barkley, an epilepsy specialist at Henry
Ford Hospital in Detroit, says he would not be surprised if the review
shows high rates of suicidal behavior. People with epilepsy have about
twice the rate of depression as the general population, he says, and
depression rates are also high among bipolar patients, who may take
anti-convulsants. "I doubt that one anti-convulsant will be any worse
than others," he says.
Neurontin sales fell 74% in the first quarter to
$182 million because of new generic competition.
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