At Issue: Concern That Drugs May Increase Risk of Asthma Attacks
By Todd Zwillich
WebMD Medical News
Latest MedicineNet News
Reviewed By Brunilda
on Wednesday, July 13, 2005
July 13, 2005 -- An FDA advisory panel recommended Wednesday that three popular asthma drugs -- Serevent, Advair, and Foradil -- continue to be sold in U.S. pharmacies.
The FDA often follows the advice of its advisory panels, but it's not required to do so.
All three drugs are long-acting medications. Serevent and Advair contain an active ingredient called salmeterol.
Foradil has a different active ingredient but is in the same class of drugs. Panelists stopped short of recommending a "black box" warning for Foradil, which is the most serious type of warning placed on prescription medications. That type of warning now appears on the labels of Serevent and Advair.
But the panel recommended that Foradil's package insert mention possible safety concerns because Foradil is in the same class of drugs.
In August 2003 the FDA added a black box warning to Serevent and Advair.
At the time, the FDA stated that the warning label for Serevent and Advair was based on a "small but significant increased risk of life-threatening asthma attacks or asthma-related deaths seen in patients taking salmeterol in a recently completed U.S. study."
The 28-week study was halted in January 2003 by Serevent's maker, GlaxoSmithKline.
FDA safety reviewer David Graham, MD, voiced concern about Serevent -- as well as other drugs unrelated to asthma -- during congressional drug safety hearings last November.
The FDA asked for the panel's advice on the topic.
Regulators were concerned that the drug's warnings were not strong or specific enough because of data suggesting that the drug's risks may be higher for blacks.
Today, experts expressed worry about the results in blacks but said they don't have enough evidence to make a more specific warning about the drug. Researchers don't know whether apparent safety differences are due to genetic factors, disparities in access to medical care, or both.
Several experts also said they were reluctant to add a race-based warning that could drive blacks away from the drug.
Speakers at today's meeting voiced some concerns about the class of asthma drugs.
"I have significant concern that it is a class effect," said Steven E. Gay, MD, director of pulmonary and critical care medicine at the University of Michigan Health System and a member of the panel.
"I have concerns that until proven otherwise we have to make ourselves believe that formoterol [Foradil's active ingredient] may act the same way," said Gay.
"The bottom line is we have no idea one way or the other. It's just an unknown whether formoterol would have similar findings or not," said Robert Myers, MD, head of the FDA office responsible for evaluating respiratory drugs.
Drug Companies' Responses
Drug company officials expressed confidence in their products.
Serevent and Advair are both made by GlaxoSmithKline. Foradil is made by Novartis and marketed in the U.S. by Schering-Plough.
GlaxoSmithKline and Novartis are WebMD sponsors.
"The benefits of salmeterol have been well established and salmeterol has been accepted as having an integral role in the treatment of asthma," said Katherine Knobil, MD, GlaxoSmithKline's vice president for respiratory clinical development.
Drug company officials said they launching new trials to learn more about safety issues in this class of drugs.
Novartis and Schering-Plough stated that they would "work closely" with the FDA to change Foradil's package insert if the FDA took the panel's advice.
A GlaxoSmithKline statement reads:
"Patients should be reassured that Serevent and Advair will continue to be available for the treatment of asthma. Serevent is one of the most extensively studied products for asthma treatment in the world and we remain committed to continuing research."
The statement was made by Kathy Rickard, MD, vice president of clinical development and medical affairs at GlaxoSmithKline.
Misuse a Concern
The drugs work by dilating the lung's bronchial tubes, which become constricted and make it difficult for asthmatics to breathe.
Patients are supposed to take the long-acting drugs consistently, usually twice a day, for long-term management of symptoms - not for immediate relief from asthma attacks.
But there is some concern that some patients may use the drugs inappropriately for quick asthma relief.
The medications can also cause abnormal heart rhythms at high doses, meaning that patients could be at risk of overdose if they take large amounts to try to ease an acute attack.
Chris Ward, president of the Asthma and Allergy Foundation of America, an industry sponsored patient group, had urged the committee to let all three drugs stay on the market because they have effectively treated asthma in millions of patients.
"We believe it would be difficult for asthma patients to understand why these products would not continue to be available to them," he said.
With reporting by Miranda Hitti.
SOURCES: Erik R. Swenson, MD, professor of pulmonary medicine, University of Washington. Katherine Knobil, MD, vice president for regulatory affairs, GlaxoSmithKline. Steven E. Gay, MD, director of pulmonary and critical care medicine, University of Michigan Health System. Robert Myers, MD, director, FDA office of drug evaluation. Chris Ward, president of the Asthma and Allergy Foundation of America. News release, Schering-Plough. News release, GlaxoSmithKline. Associated Press. WebMD Medical News: "FDA Issues Warning for Serevent, Advair." WebMD Medical News: "Safety Concerns Halt Asthma Drug Study." WebMD Medical News: "FDA Scientist Concerned About Five Drugs on Market." Lisa Behrens, spokeswoman, GlaxoSmithKline. Julie Lux, spokeswoman, Schering-Plough.
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