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Update: Singulair And That Black Box Warning

Montelukast (Singulair)was approved by the FDA in 1998, 1 although I wasn’t prescribed it until March of 2008.  At the time my doctor said it was overhyped, although he agreed to let me try it. That spring was the first time in my life I made it through pollen season without feeling miserable due to sniffles, sneezes, and wheezes.

Little did I know at the time, in September of 2008 the Associated Press reported on a 15-year-old high school football player who started taking Singulair in 2007 due to an allergy to ragweed. Within weeks his parents noted he was feeling agitated and having trouble sleeping, and 17 days after starting the medicine he committed suicide. Singulair was blamed, and the case was reported to the FDA. 2

FDA investigates Singulair and suicides

In March of 2008, the FDA announced it was performing a review of the links between Singulair and psychological events (mood and behavioral changes). Shortly thereafter there were similar reports. 1

Prior to this time, the FDA only investigated psychiatric drugs for potential suicide risks. However, these reports opened the doors for them investigating other drugs that have the potential for crossing the blood brain barrier and having an effect on the mind, and this included asthma medicines. 2

During its first ten years on the market, Singulair became the best selling drug for Merck. In 2007 alone, sales were $3.4 billion. Merck reported that none of the 11,000 participants involved in initial studies of Singulair reported psychological events.

However, just to be on the safe side, and before any further studies were conducted, the FDA issued warnings on the products so that the public — asthmatics, parents, and doctors alike — were well aware of these reports. 3-4

FDA finds no evidence linking Singulair with suicides

In September 2008, the FDA released a report of its own study of the “well-being” of 536 people taking Singulair. Of them, there were no reports of “psychiatric problems, depressive episodes, or suicide.” In fact, the study actually showed an improvement in well-being among asthmatics taking Singulair, compared to asthmatics who were not. Later,  the FDA confirmed Merck’s claim that, of 40 studies of over 11,000 people taking Singulair, there were no reports of suicides. 2, 5  

Despite this report, the black box warning remained, mainly because the claims could not be disproved beyond a reasonable doubt. The warning has been changed quite a few times over the past decade, and currently reads.

“SINGULAIR may cause serious side effects. Behavior and mood-related changes. Tell your healthcare provider right away if you or your child have any of these symptoms while taking SINGULAIR: agitation including aggressive behavior or hostility, attention problems, bad or vivid dreams, depression, disorientation (confusion), feeling anxious, hallucinations (seeing or hearing things that are not really there, irritability, memory problems, restlessness, sleepwalking, suicidal thoughts and actions, including suicide), tremor, trouble sleeping, uncontrolled muscle movements.”

Concerns about Singulair black box warning begin to mount

This was thought to be good in that it would make the public aware of the reports, and hopefully inspire patient-physician or parent-physician discussions. However, most doctors ignored the warnings — including my own doctor at that time, and continued prescribing the medicine anyway, usually without issuing any warnings. The main reason was because they had already prescribed the medicine to so many asthmatics with good results.4

Another concern among the medical community about the warnings was that they might scare some asthmatics (or their parents), thereby preventing some asthmatics from taking a medicine that might otherwise help them obtain improved allergy and asthma control.2

This is actually the reason I decided to write this update. My 14-year-old daughter, like me, has asthma and severe allergies. Now that my allergic asthma is relatively controlled thanks to both Advair and Singulair, I thought Singulair would help her control her allergies. So I discussed the idea of having my daughter’s pediatrician prescribe it for her. My wife was concerned due to the warnings.

My wife, my daughter, and I have had some nice discussions about Singulair. So far my daughter is managing without it. Still, there are mornings where she’s sniffling and sneezing quite a bit, so there’s a part of me that wonders if Singulair would be good for her, perhaps even improve her well-being. Perhaps she will have to end up making the decision on her own someday.

Links to psychiatric events renewed

The issue of Singulair and Psychiatric events was brought up again on September 23, 2014, at a Pediatric Advisory Committee. Addressing the concerns of a parent who addressed the committee, the members reviewed the current data and determined that, despite the previously mentioned studies, there were many reports of patients or parents reporting psychiatric events, such as the ones mentioned in the black box warning listed above. While most psychiatric events reported were “not serious,” all were reversed after cessation of the product.  1, 7

To address these concerns, the members of the committee discussed the need to communicate with physicians to raise awareness of possible psychiatric side effects, to discuss possible side effects with patients/parents, to monitor patients for signs of psychiatric events, and to discontinue the medicine if any signs of psychiatric events are observed. 1, 7

What can we conclude here? 

Singulair is the most commonly prescribed leukotriene antagonist, so it’s often the one mentioned in reports of adverse side effects and involved in studies. However, to be on the safe side, the same warnings on Singulair products have also been added to other leukotriene antagonist products, including zileuton Zyflo, and zafirlukast (Accolate).

It’s also advised that if someone experiences psychiatric events while taking one antileukine antagonist, that all leukotriene antagonists be avoided. Another recommendation by the committed was further studies on this issue. However, because current labeling is quite clear, and because this is a known issue, the FDA did not agree that further changes to information to physicians nor studies were warranted at this time. 7

So, that’s where we stand today. Thoughts?

This article represents the opinions, thoughts, and experiences of the author; none of this content has been paid for by any advertiser. The team does not recommend or endorse any products or treatments discussed herein. Learn more about how we maintain editorial integrity here.

  1. Pediatric Advisory Committee Meeting, “Montelukast or Singulair,” United States Food and Drug Administration, Minutes, 2014, Tuesday, Sept. 23,, accessed 6/9/17
  2. “Connection Between Prescription Drugs, Suicide Studied,” Fox News, 2008, September 2,, accessed 6/9/17
  3. Akre, Jane, “FDA Issues Early Warning On Singulair And Suicides,” National Newsdesk, 2008, March 28,, accessed 6/9/17
  4. Radha, Chitale,“Doctors Not Concerned by US FDA Probing Safety of Merck's Singulair,” CBS News, 2008, March 27,, accessed 8/7/17
  5. “Analysis Finds No Singulair Suicide Link,” CBS News, 2008, September 5,, accessed 6/9/17
  6. Paggiaro, et al., “Montelukast in Asthma: A Review of its Efficacy And Place in Asthma,”   Therapeutic Advances in Chronic Disease, 2011, Jan.,, accessed 8/7/17
  7. Scudder, Laurie, “Montelukast’s Under recognized Adverse Drug Events,” Medscape, 2015, March 2,, accessed 8/8/17


  • jakeb
    11 months ago

    Max – I’d be interested in discussing this with you in more depth.

    My experience with singular/montelukast was extremely similar to yours. I have anxiety, panic attacks, nightmares and fears all of which I never experienced before taking this drug.

    It’s been 3 months since I quit taking singular (I took it daily for 2 months). And I am still definitely not back to normal. I’ve been digging around on the web but haven’t found any clear solution/supplement to get my brain levels back to where they were. It is negatively effecting my life in a serious way and I will do anything to fix it.

  • Leon Lebowitz, RRT moderator
    11 months ago

    Hi Jakeb and thanks for your post. I’m sorry to hear that you have had this experience using Singulair. Are you using something else now that you’re off that medication? Is your physician aware of the side effects you experienced?
    Have you considered reporting your experiences to the FDA?
    Leon (site moderator)

  • MaxC
    2 years ago

    One more thing…I only reported this to my doctor at the time. Other that that who can we reach out to so that our name and story get added to their data?

  • John Bottrell, RRT moderator author
    2 years ago

    Hi. MaxC. Sorry to hear you had so much trouble with singular. To report adverse side effects, contact the FDA. You can do so by clicking the following outside link. John. Site Moderator

  • jocsuiter
    2 years ago

    My son was on Singulair for nearly two years. Neither his GP, his allergy specialist nor the pharmacist warned us about any possible side effects. There is no warning label on the box in Australia. My son developed insomnia, anxiety, emotional outbursts, pains in his legs and stomach, and wanted to go to the toilet all the time. Our family suffered through this for years, thinking it was related to an anaphylaxis episode, until a light bulb went off in my head and I Googled Singulair side effects. When he stopped taking Singulair, his insomnia stopped. It took longer for the anxiety to dissipate, and it returns if he has artificial sweeteners, or is sick. More research needs to be done on the long-term side effects of this medication. Why does it affect some children and not others? If we knew this, then doctors could know who NOT to prescribe it to.

  • MaxC
    2 years ago

    As an adult, I was on Singulair for a few weeks and started to notice several of the side-effects that were on the label at the time. This included stomach pains, chills, anxiety, bad dreams about my pets dying (yes that was a listed side effect), and depression. I would watch TV and get 2nd hand anxiety from what they were doing. For example if they were climbing a mountaian I would get a sudden fear of heights. It got to the point where I could not watch TV for long time. At first, I thought I had some exotic virus but then after reading the side-effect, I quickly stopped taking Singulair. I started to get better, but it went in waves, I had good weeks and bad weeks. I blame it for leaving me more open to anxiety and depression, 2 things I never had prior to using this drug. I would rather suffer allergies/asthma or break something physically than go on this “medication” again. I warn everyone I know about this medication…especially children who are more prone have this pass the blood-brain barrier.

  • John Bottrell, RRT moderator author
    2 years ago

    Hi. jocsuiter. Agreed. I have researched this quite a bit because I take this medicine and so too do my kids. I think there are so many who benefit from this medicine that potential side effects often go overlooked. So, rest assured that researchers continue to study this medicine to answer questions such as the ones you pose here. Thanks for sharing. John. Site Moderator.

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