On Tuesday, the FDA announced that an investigation into Merck’s clinical trial data did not discover a link between Singulair (montelukast) and suicidal behavior. The investigation, which began 9 months ago, was prompted by a number of reported suicides, especially that of 15-year-old Cody Miller who took the drug and appeared to have no history of mood or behavioral problems. (It is worth noting here that Singulair “is the top-selling drug for people under 17 years old” and Merck’s biggest seller with annual sales of close to $4.5 billion.)
In attempt to assess Merck’s data better, the FDA also investigated AstraZeneca’s Accolate (zafirlukast) and Cornerstone Therapeutics’s Zyflo (zileuton). Although the FDA did imply that “the data were inadequate to draw a firm conclusion” and said that the clinical trials were not set up to observe any psychiatric behavior. Here are the data the FDA discovered during their review of these trials:
Singulair: 41 placebo-controlled trials that included 9,929 patients
- Reports of suicidal thoughts: 1 (treated with Singulair)
- Attempted suicides: None reported
- Completed suicides: None reported
Accolate: 45 placebo-controlled trials that included 7,540 patients
- Reports of suicidal thoughts: 1 (placebo group)
- Attempted suicides: 1 (placebo group)
- Completed suicides: None reported
Zyflo: 11 placebo-controlled trials (number of patients unknown)
- Reports of suicidal thoughts: None reported
- Attempted suicides: None reported
- Completed suicides: None reported
Forgive me for being cynical but the data sounds fishy. I can’t pinpoint why but it does. The suicide numbers and patient involvement data seem to deviate some from the numbers listed in Merck’s PR issued last March. (I’m seeing 11,000+ patients vs. 9,929 patients.) Regardless of the clinical trial data, it appears that the FDA as of yet have not reviewed post-marketing data.
Scott Korn, a senior safety surveillance executive for Merck said in an article for Reuters:
“‘At the time we did not believe, and we still don’t think a link has been established’ between Singulair and the suicides.”
In the same article, Sanford Berstein analyst Tim Anderson had this to say about the possibility of the FDA finding a link:
“If the… safety review leads to a stern warning about behavioral changes in the Singulair label, this could frighten users of the drug or their parents and give Merck’s competitors ammunition to attack the brand.”
The Washington Post has Dr. David Weldon, director of the Allergy and Pulmonary Lab Services at Scott & White in College Station, Texas, on record saying that he had not “seen any increase in psychiatric problems with the drug but that some patients had complained of nightmares after starting on Singulair.” (Note: It appears that the closest conflict of interest Weldon would have here is that he served as a consultant and is honoraria for AstraZeneca.)
Dr. Rauno Joks, head of the SUNY Downstate division of allergy and immunology, made an interesting point in the Washington Post article:
“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.
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.”
The FDA says they’ve completed analyses of submitted clinical trial data but their “safety review will continue” for several more months before they come to a concrete conclusion. For customer testimonials, check out medications.com that has over 2,300 people reporting side effects and askapatient.com that has an average 2.3 rating from 524 reviewers. The most commonly reported mood-related side effect on both of the sites is irritability.