"We still believe, after a thorough review of our clinical trial data and postmarketing event reports that the safety profile of Singulair hasn't changed," Dr. Scott Korn, vice president for clinical risk management, said at the time. "We look forward to discussions with the FDA after they've completed their work."
Before last year's review began, Merck had updated prescribing information for Singulair to include information on several adverse events including tremor, depression, suicidality (suicidal thinking and behavior) and anxiousness, according to the FDA.
When the review began, experts pointed out that while it was under way, asthma sufferers needed to determine with their doctors whether Singulair is the best treatment for them.
"[Patients need] to define what they're taking it for," said Dr. David Weldon, director of the Allergy and Pulmonary Lab Services at Scott & White in College Station, Texas. "In some instances, patients may be prescribed Singulair by itself for management of their asthma, and the expert panel guidelines recommend inhaled steroids as the drug of choice for management of asthma as the first line. So if they're still having problems with asthma, they should check with their prescribing physician regarding this."
Weldon said that he has not seen any increase in psychiatric problems with the drug, but that some patients had complained of nightmares after starting on Singulair.
"The physician really needs to review whether there are symptoms that have developed since patients started taking the medication, if there's an underlying depression that was there before medication started," added Dr. Rauno Joks, chief of the division of allergy and immunology at SUNY (State University of New York) Downstate in New York City. "Also, seasonal allergies in and of themselves can cause fatigue and lethargy, which makes it harder to assess, because those are some of the symptoms you have with depression."
Joks said he had seen headaches develop as a side effect of Singulair, but not psychiatric problems.
Leukotriene receptor antagonists target part of the body's inflammatory process. They are prescribed to treat asthma and the symptoms of allergic rhinitis, as well as to prevent exercise-induced asthma.
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SOURCES: June 12, 2009, statement, U.S. Food and Drug Administration; Bloomberg News; Associated Press; David Weldon, M.D., assistant professor, internal medicine, Texas A&M Health Science Center College of Medicine, and director, Allergy and Pulmonary Lab Services, Scott & White, College Station; Rauno Joks, M.D., associate professor, clinical medicine, and chief, division of allergy and immunology, SUNY (State University of New York) Downstate, New York City