Singulair is used to treat asthma and allergies.

Full prescribing information is available at:


Check out Wikipedia for more user-friendly information:


Join Over 80,000 Subscribers at The People's Pharmacy

Each week we send two free email newsletters with breaking health news, prescription drug information, home remedies and a preview of our award-winning radio show. Join our mailing list and get the information you need to make confident choices about your health.

  1. Janelle

    Thank you Dr. David for Fda link to report ineffectiveness of generic forms of montelukast. I have submitted my complaints and request for generics to have 90-100% comparative effectiveness to brand Singulair.

  2. Janelle

    I have been taking montelukast for almost 20 years to control severe allergy symptoms and prevent asthmatic episodes. Brand Singulair gave me relief year round.
    Then I began the generics supplied by Kroger pharmacy when they became available, and experienced some break-through symptoms during certain pollen seasons. Each year my symptoms have appeared more often.
    I have tried 4 different generic options offered by Kroger, CVS, and Publix and have not yet found a generic product as effective as the brand Singulair. I pay $600 a month for my health care insurance including pharmacy coverage (note: my cost for same health care coverage was $300 Per month until the new health care coverage “Obama Care” came into effect) and cannot get my insurance company to help with the cost of the brand Singulair.
    As a result I am undergoing pulmonary tests, lung cat scans and allergy tests again to prove to the insurance provider that the generic forms are not working. The insurance provider said that I had to try other forms of medication that are less expensive before they will consider paying the higher costs for a brand name medication. When I explained my history of using many forms of generics that are not effective they said that a specialist needed to confirm my need for brand Singulair as opposed to my family MD.
    I am glad more people are receiving healthcare coverage As a result of me having to pay double for my coverage, but substandard healthcare coverage for all of us is not an acceptable consequence.

  3. Elaine
    southern ohio

    I had always used Singulair until my insurance had my mail order prescription send me the generic form. I suddenly couldn’t breathe as well and contacted a very serious lung infection. The lung specialist, medical doctor, and ent all said they didn’t understand what was going on. They said they were doing everything they could, but I still had the severe cough and asthma symptoms. I then asked the mail order pharmacy to send the brand name Singulair. Within two days I felt as though the heaviness from the asthma had lifted. I’ve stayed on the brand name every since and don’t have any problems. It’s the same with Synthroid. I now take Nature Throid.

  4. Suzanne

    Since I was switched to the generic of Singulair, I am always breathing hard. I have heard that the generic I’m on is only 25 percent as effective as regular Singulair. Has anyone else had breathing problems on the generic form of Singulair?

  5. Betty
    Waltham, MA

    I got a prescription for montelukast sodium in an attempt to gain better control over my asthma after having a negative reaction to Symbicort. Within a few days, I started having pain in my knees and lower legs, and to a lesser degree, in my fingers. It seemed like many of the tendons in my body were tightening up despite frequent stretching. I also felt like I was moving much more slowly. I walk a lot, and by the fifth day my knees hurt enough that I discontinued using it.

  6. David
    Philadelphia, PA

    If enough of us report to the FDA these adverse reactions we may get some action. Report them to:

    The problems being discussed here are NOT “side effects”, minor problems that stem from or are related to the expected performance of the drug. These are “ADVERSE REACTIONS”, a category that the FDA takes seriously. They have nothing to do with the expected effect of the drug. In this case they indicate preventable faulty formulation and manufacture of the drugs and do not occur with the one Brand-Name formulation available.
    I am an MD and know from professional experience that in most cases, particularly when there is more than one independent report, the FDA takes these adverse reaction reports very seriously. A colleague’s report of what I thought was a minor problem with a device brought a phone call to us from the FDA. The second such report led to recalls and shutdown of manufacturing until changes were made. My report of a problem with a drug led to a call from the drug-maker. When they asked if we needed any more reporting forms and I told them that 5 of my colleagues needed forms they became very upset. After the next 5 reports went in the FDA required re-labeling of a dangerous but essential drug which decreased the frequency of complications related to the drug.

  7. jen

    After years of childhood asthma that disappeared when I moved to the west coast, it reappeared when I moved to Colorado. It was bad, steroids, frequent prednisone rounds, inhaled steroid treatments.. The along came Singulair. A godsend, off all of it but an occasional puff on an albuterol inhaler.

    Then came the generic.

    It doesn’t work. I don’t think it’s the additional ingredients in my case, I think it’s a fraud. My education is in medicinal chemistry with a lot of experience in pharmacokinetics, ie what happens to a drug I the body and includes how well it’s absorbed and how fast it’s metabolized. The FDA needs more money, so they can look into the BS that is the US pharmaceutical industry. It’s a fraud.

    • Lakeside Girl

      I am thrilled to have found these shared experiences. I too have had asthma for years but until one year ago it had not been suggested to me to take a pill form of medication….just the ventolin as needed. Finally I went to doc and was prescribed singulair but as we all know our insurance companies are trumping our choice for brand name and gave me the montelukast. I had had nothing to compare it to. For one year I have lived with intense dreams that I could write chapter books from. I have slept so hard I would need 3-4 time slots for my alarm to go off to wake me in the mornings. I am a morning person so this wasn’t working.

      Recently, I have had more asthma attacks an ever before and many at night time. I realized that in the past year our pharmacy had changed “generic” suppliers twice. This last time I realized my asthma symptoms were worsening to two and three episodes a day. I can’t live that way.

      So I recently asked my doc if he would prescribe the brand name and thank God he did and my insurance co. did not object but my co-pay has increased to about $25. It is worth it. Asthma attacks, especially at night while I am sleeping, is disruptive enough I can’t get a good nights sleep after it is under control.

      It’s good to know others have had the same plight with generic montelukast. I feel like our choices with medicines are being more and more controlled by someone else to the point we no longer have choices. I have the same problem with Synthroid.

    • Virginia
      Washington State

      I agree with you my friend. I am a Medical Dr with severe asthma. I used to use my albuterol 6-10 each night. Singulair changed my life, I have since rarely needed albuterol, advir or prednisone.

      Then I was forced into generics by my insurance company. I have tried 5 different generics, none work as well as Singulair. It is unfortunate that the FDA has not done its due diligence before releasing a lot generics. They have brainwashed the pharmacists to tell people that all of the generics are the same as the Brand name. Yet, the pharmacokinetics (how drugs are absorbed and distributed in the body) are not the same and may in fact be very different! The FDA says they are the same if they fall within a 25% range! I am sorry, but that is a huge range for a drugs efficacy that may cause it not to work!

      We also know generics often use different binders and dyes, these all can cause a reaction very different than the brand name. I am afraid the FDA has done a real disservice to the population. We are putting people into emergency rooms in the name of “saving money”.

  8. Cj

    Thanks for everyone’s comments here. I am suffering terribly in the Teva genetics: increased rhinitis, lung mucous, stomach pains, fatigue. The Singulair brand gives me my energy back and my life. It is just amazing how generics are allowed to get by with 20% difference in potency and testing is not required as it is of brands. AND after spending over an hour on the phone trying to extract inactive ingredients from my mail order pharmacy, I’ve got to ask: is there a reporting process for stuff like this? Ironically, it seems it adds to more health issues and more costs.

  9. Julie Amergian

    In February 2013 I was switched to a generic drug (Montelukast) from Singular that I had been on for about 20 years. In April 2013 I had to go to the emergency room for asthma. It was the 1st time since I had been put on Singular that I had to go to the hospital. Since then I have been struggling with my asthma and am now frequently on prednisone. I have also had fatigue and depression since being switched. I just figured it out . I am going to pay the extra money and go back on Singular. I wish that I had realized the obvious before I had to suffer so long.

  10. JEN

    I have been taking Singulair for years. My doctor wrote the prescription as a “dispense as written” because I have always had issues with starches and talcs used in generic meds. Well, my insurance company has completely disallowed brand name Singulair, so I’ve having to take the generic Montelukast since February of this year.
    My pharmacist has tried both the Teva and Apotex brands, and both give me serious indigestion with bubbles, belching, and stomach acid backing up my esophagus during the night. I have to take Zantac just to calm the indigestion so I can sleep. Can’t take it at other times because I have both asthma and allergies – bedtime is when you have to take it when that’s the case.
    I did some research on the inactive ingredients – the stuff that makes up the tablet and was appalled! Singulair has 5 ingredients: microcrystalline cellulose, lactose monohydrate, croscarmellose sodium, hydroxypropyl cellulose, and magnesium stearate. The 5 generics on the market range from 10-13 inactive ingredients. Some have 3-5 of Singulair’s ingredients plus many more – some are laxatives (polyvinyl glycol, polyethylene glycol, macrogol) to help with breaking down the pill in the gut. All 5 generics contain titanium dioxide, and 4 of them contain red and yellow iron oxide (the 5th contains FD&C red and yellow dyes). My pharmacist focused on those as the most likely suspects – he sees many customers who have problems with iron oxides and with titanium dioxide.
    I noticed several references in these comments to Mylan’s generic. Here are the ingredients for that one: silicon dioxide, croscarmellose sodium, fd&c blue no. 2, fd&c yellow no. 6, hypromelloses, magnesium stearate, mannitol, cellulose, microcrystalline, polydextrose, polyethylene glycols, sodium lauryl sulfate, titanium dioxide, triacetin. Notice that there is mannitol (an alcohol-based sugar) – that ingredient has been associated with gastric upset when used in sugar-free products and in no longer included in gums and candies because of problems with kids and GI upset.
    I’m fighting my insurance company. So far, even though they tell me they have a process for appeals, they tell me not to bother because they’re not even going to consider it. Now I’m armed with ingredient lists and will consult my allergist about potential allergies – the titanium dioxide is a strong potential since I’ve had problems with other pills that contain that ingredient.
    So, fight for the brand! Singulair doesn’t work for a ton of folks, but when it does, it’s awesome! Has really controlled my nighttime asthma and is the one med that I take that I really notice if I run out. Once I found out how much junk was in the other pills, I’m really convinced that many side effects to generic medicines are due to the inactive ingredients.
    And one other note, when the generics cite side effects and research findings, they’re just reporting the clinical studies that were originally done for montelukast when it was developed as Singulair. They NEVER do additional clinicals on generics to test for side effects to the inactive ingredients – I suspect many of the problems we are all encountering are due to untested inactive ingredients used to make the pill itself.

    • Sally

      My husband was willing to pay extra to get his prescription for Singular after trying Teva’s generic with similar miserable side effects to those warned about. Suddenly, after signing up for his Part D drug plan, the cost of the co-pay went from $45 to $98. WHAT? Under the insurance agreement, as a non-preferred medication, he has to pay 50% of the cost of the drug. The insurance company has said the cost of Singulair has gone up. The cost of Singular for someone who is not insured varies in our community from $262 at Walmart to $254 at Walgreen’s to $188 at our local pharmacy.

  11. RSH

    I’ve suffered ever since roughly end of 2012 with amazing & terrorizing nightmares. Worse, I’d typically would awaken around 4 a.m. (after taking Montelukast about 11 p.m.) with my mind racing, and incredibly “moody” thoughts. I suppose suicidal thoughts is what people are too afraid to say—not me. Day after day I contemplated suicide…and I’m doing great, all things considered.
    Unfortunately, with a rotten childhood, it did seem “a good idea”, this suicide ideation. It passed once I was on my own, financially secure, married, happier, etc. Then, when my life was really improving and stable (now 61), the odd suicide ideation had returned…so subtley. Been off the Montelukast, no more ideation. Between pharmaceutical companies & insurance companies trying to make as much money as possible (thanks, Congress), I don’t see how the average person can hope to survive better. Doctors? Please, I keep getting a new one each year their contract is up—it’s Florida.

  12. J.C .W.

    Generic singulair does not work for me and it looks like I am not alone. I once paid around $60.00 for singulair but when I checked with a couple of pharmacies they informed me that singulair now costs about $240.00+.

  13. SHL

    To DZ: We had a grandson on Singulair daily for asthma/skin problems when he was in K-5 and he started having behavioral problems that were not at all normal for him. When the Singulair was stopped, he quit misbehaving.

  14. dz

    I recently started having problems with my marriage. I was told that they started 8 months ago. I realized that 1 month prior to the changes I started taking montelukast. I took Singulair as a child and it worked well. My insurance changed me to the generic and over the last 8 months or so, I have experienced many side effects that unfortunately I was unwilling to admit.
    The side effects were suicidal thoughts (nothing attempted thank god), fatigue, depression, weird dreams, mood swings. I am not blaming the drug for my relationship issues. Some of the issues are mine and I recognize and take responsibility for them. I just wanted to share because if I didn’t have a loving wife and didn’t see the connection with the drugs I may have lost my marriage.

  15. LQ

    I have began experiencing many symptoms of asthma since switching from singular to the generic version too. My asthma was under control for a very long time while on Singular. this year and herbal pills with the new generic version of this medication.

  16. MC

    there have been several reports on substitution from Singulair to generic, I had abnormal dreams myself when taking the generic. now back to brand. Do not know which generic montelukast this was.

  17. SHL

    I agree, generally I am not opposed to generics. I take a Teva blood pressure medication and do very well on it.
    What really gets me, is the Insurers will not pay on a name brand prescription what they would pay for the generic. I have had twice the number of sinus infections which invariably turn into bronchitis since I had to leave Singulair. I got sixty Singulair tablets in Italy for 40 Euro and felt much better while on them.

  18. CM

    I had been taking Singulair for about a year when my drug plan required a switch to generic Montelukast. Unlike others here, I began taking the generic made or marketed by Teva, and not only experienced no improvement in my symptoms, but also experienced unpleasant side effects, such as nasal drainage that gave me a sore throat.
    The next time I saw my allergist, he noted that my condition had worsened and said that he would have to prescribe an additional drug to control the symptoms. Because an online search confirmed that others had experienced problems with the Teva generic, I began to look for an alternative, and found Mylan. My pharmacy initially told me that it could supply only Teva, which was frustrating, but my new doctor specified Mylan generic, and to my surprise, the pharmacy then changed its tune, supplying that drug, which has worked for me.
    I am happy about this, because I did not want my plan to have to pay for the more expensive brand-name drug or to pay for another drug to offset the Teva side effects. The point is that side effects and efficacy will vary from patient to patient, and a generic may be acceptable, provided that you find the one that works for you. And be sure to check the bottle prior to accepting the drug from the pharmacy each time, to ensure that the generic that has been filled is the one you want.
    P.S. I was recently prescribed my doctor’s preferred drug for another condition, and was not certain that the Teva generic for that worked, either, so I did another online search for patient reviews. Patients who had taken the name brand extended-release drug and had switched to generic stated that the generic did not work nearly as well, with some patients actually reporting hospitalization due to the failure of the drug.
    Because I had never taken the name brand, I really did not even know whether the drug as initially approved by the FDA would work for me, and I did not want to have the generic dosage increased unnecessarily or to switch to another drug that might have more side effects, so I asked my doctor to specify name brand only for a month’s worth of pills. My insurance company would not pay for this, so of course it was much more costly, but if it works, the doctor will justify the name brand or we will search for a better generic. As a patient, I am not opposed to generics, and even prefer them if they work, but I resent that pharmacies and drug plans seem to have struck deals with generic manufacturers that restrict the ‘brand’ of generic available to the patient, regardless of its efficacy and ultimate increased cost to both the patient and the plan.

  19. SHL

    Thanks, VK I will refer back to your remarks if I cannot get the Apotex. My independant pharmacist is able to buy from different suppliers which so far is allowing me to get Apotex. The large chain drug stores are not able to do this. Your experiences seem to echo mine. I am so busy at work that having to deal with this new insurance form of “socialized medicine” is truly a pain and an unnecessary source of stress. Still say that the trouble, the illnesses, and the wasted time off are not conducive to efficiency or health.

  20. VK

    If you are given a generic form of singulair. Write down the manufacturer. There seems to be over a dozen different ones…and they are not the same.
    Most pharmacies only carry one…and they frequently switch. I had three manufacturers this year. Some work fairly well…some are not good at all.
    I agree with the above Apotex did seem to be one of the best. Also Aurobindo was good.
    Once you find one that works….check before you refill…if they switched..look for another pharmacy. If you are doing mail order..you may need to appeal to your insurance company to have them let you fill your 90 day at a retail pharmacy because they don’t carry the generic that works for you. This is what I had to do..its a pain…but still better then wheezing all the time.
    It would be cheaper for me to find a generic that works and pay for it out of pocket..than try to get Singulair..name brand. Most insurance policies have a new clause which says that if a generic is available, and the patient chooses to use name brand, the patient is responsible for the co-pay..PLUS the difference in price between the generic and the name brand. This means that last year before Singulair went generic I could get 90 days for $105. Now it will cost me $465.02!

  21. SHL

    Well, I’ve been on Montelukast Sodium Tablets 10 mg manufactured by Apotex Research Pvt. Ltd. for about 10 days and seem to be better. I still believe I was better on Singulair but am willing to try this generic for another month. So far so good.

  22. EE

    problem with generic singulair here. Been on brand name for 6 years, switched 2 weeks ago and I can not get rid of my head ache and have extreme tiredness. Switching back to brand name as of tonight; not sure what to do with the 6 month supply of the poor quality generic stuff that I have left.

  23. SHL

    Well, it has happened again. Switched by pharmacy to Montelukast manufactured by Dr. Reddy. Horrible bout with bronchitis, days off work, shots, strong antibiotic, inhalers, etc. Really sick. Did not associate with Singulair substitute until three weeks later when I could not sit through an hour’s meeting without coughing. Have been experiencing shortness of breath since bout with bronchitis but just didn’t blame the drug until nothing else seemed to help. So, I can take the substitute made by Mylan if I can find it, but it nauseates me somewhat (like aspertame).
    The Teva and Dr. Reddy generics do not work on me. So tomorrow, I start my hunt for a new generic to try. I just wonder how long it will take insurance companies to realize that these generics do not work and are costing them money, not to mention the health of their rate payers.

  24. SGO

    I’ve been on Singulair for about 10 years and NEVER had an asthma attack while using it. I have been on the generic version Montelukast for over 6 months and have experienced numerous and very serious asthma attacks, shortness of breath and unable to breathe deeply as I could when I was on Singulair.
    Somehow, I made the connection that it must be the Montelukast not working for me. I requested my doctor to prescribe ONLY Singulair for me, which she did. I will never go back to the generic version again! It’s worth having to pay more out-of-pocket money for something that works and potentially saves my life.

  25. BME

    Thank you so much. I knew I was not losing my mind. I too have been on Singulair for about 6 years. I got a refill and went down hill after 5 weeks. I could not figure out what was wrong with me until a co-worker asked about my asthma and allergy meds. She mentioned she had gotten switched from Singulair to Montelukast due to insurance. Sure enough, that is what happened to me. Unfortunately, my doctor argued with me about it being my imagination. Meanwhile, I am suffering with my breathing. This ridiculous.

  26. SHL

    @ MD, No a generic and a placebo are two different things. The generic has to be 81% similar to the original drug, in this case Singulair. Generics are made by many different companies and therefore that 19% can be different in each manufacturer. So please, if you are not getting the relief you had enjoyed previously from Singulair, tell your pharmacist and get some by another manufacturer. It worked for me. If you get no relief from any of the generics, go back to Singulair and just pay the differenct. Breathing is that important!

What Do You Think?

We invite you to share your thoughts with others, but remember that our comment section is a public forum. Please do not use your full first and last name if you want to keep details of your medical history anonymous. A first name and last initial or a pseudonym is acceptable. Advice from other commenters on this website is not a substitute for medical attention. Do not stop any medicine without checking with the prescriber. Stopping medication suddenly could result in serious harm. We expect comments to be civil in tone and language. By commenting, you agree to abide by our commenting policy and website terms & conditions. Comments that do not follow these policies will not be posted.