Montelukast and Tiredness: What Users Say

• Ang...
• March 9, 2020

Montelukast for Asthma "Be careful! After years of being misdiagnosed, I was given Singulair. Within 4 weeks, I no longer needed my nebulizer or rescue inhalers. I gradually became more tired and extremely agitated. I began hearing voices in my own home, and I live alone. It got worse, not better. One night, I was convinced someone was in my home. Every light in the house was on. I still kept seeing someone! Coming from a military background and secure in owning firearms, I was searching my home with a gun. I was looking for an intruder who was NOT there! That was my final straw. I threw my Singulair in the garbage. I’m still agitated and frustrated. I am going to try over-the-counter medication deemed safe. I’m not sure how long the agitation and tiredness will last. I pray this will help someone. Please be careful on this medicine. For me, it’s not worth it. In 55 years, I’ve never seen anyone or heard voices in my home until Singulair. (5 weeks total taking it)"

• Gir...
• Taken for 1 to 6 months
• August 17, 2019

For Asthma "I have noticed a lot of bloating and hot flashes on montelukast. I do feel like it helps with the cough I get from allergies and shortness of breath. On the other hand, I have been gaining unexplained weight and extremely tired!"

• Ver...
• November 5, 2016

Montelukast for Asthma "Since taking Singulair I have tooth pain, tingling in my face, and a bad metallic taste in my mouth. Plus my anxiety level went up, feel really tired, and very agitated. Stopped taking it last night. Hope these side effects go away soon. This metallic taste is driving me crazy! This is the 2nd time I've tried it. Same side effects and more."

• Gco...
• October 19, 2016

Montelukast for Allergic Rhinitis "My wife was on this stuff for at least a couple of years. She suffered severe tiredness, nightmares, irritability, and even suicidal thoughts, accompanied by severe depression! Although it did make her feel better, the side effects are not worth it at all! She switched to Flonase, and it is just as good. Please, if you are on this medicine and have any of these side effects, please stop!"

• Cas...
• April 7, 2015

Montelukast for Allergic Rhinitis "Been suffering from ETD for about two years. I've been on Singulair for about 4 months, and it has dramatically improved my symptoms, no more ear crackling. Occasional tiredness and headache, but it's tolerable. It has helped me tremendously."

• Anonymous
• Taken for 2 to 5 years
• September 21, 2012

Montelukast for Asthma "This really did help with my allergies and asthma symptoms I sometimes experienced. I took this for 2 years and never on a daily basis, but as needed (when my allergies would act up). It took me a while to figure this out, but I have now determined that when taking this medicine, I am very lethargic the next day, depressed feeling, and extremely agitated. For a while, I had just concluded I was a moody person, but after taking one, seeing how I felt, and then going off of it, I put two and two together. Literally, the next day without the pill, I feel back to my old self. So though it did help for allergies, for me, the pros don't outweigh the cons."

• Nos...
• September 12, 2015

Montelukast for Allergic Rhinitis "I have severe allergies every day right when I get up in the morning. My nose just starts to run and drip. If I do not have tissues, my mucus would just drip on the floor. My allergies always go away around lunchtime. I took generic Singulair (montelukast sodium) every day in the morning. Then I switched to the evening. I may have only missed one or two tablets throughout the 3 months that I took it, but my drip is the same as before. This medication does not work for me. I have tried the generics for Claritin, Allegra, and Zyrtec. Now I have tried the generic form of Singulair. All of these medications do not work for me. The only medication that works is Benadryl, but Benadryl makes me so exhausted and congested."

• Mel...
• Taken for less than 1 month
• January 11, 2019

For Asthma "I experienced horrific side effects from this drug. After about 4 days of taking it, I developed anxiety and depression, body aches, and an extreme feeling of tiredness. I stopped taking it right away, but I had flu-like symptoms for the next 5 days or so, where I could not even get out of bed. I'm now on day 9 off the drug, and am slowly getting back to myself but still feeling quite tired, sleepy, and anxious."

• Gai...
• December 24, 2017

Montelukast for Allergic Rhinitis "This drug did nothing for my stuffy nose, cold, cough, and wheezing, but the side effects are horrible. After less than a week of taking it, I could not sleep, was unable to focus, had a panic attack at the grocery store with sweating and dizziness, felt like I was going to faint, was very tired and achy. I did not connect it to the drug at first, but then I went to take it, and it dawned on me that maybe I should check out the side effects. These are all side effects of the medication. I had lost my mother about a month ago, and I kept thinking I was just not coping well, but once I stopped taking the medication, I was able to sleep and the sweating and dizziness went away. My aches are much less as well."

• Hum...
• Taken for less than 1 month
• December 5, 2019

For Asthma "I took this medication for two days. The side effects were overwhelming. I got a fever and the flu symptoms within the short time I was on the Singulair. I was also extremely tired, so much so I was unable to work."

• Su_...
• December 26, 2016

For Asthma, Maintenance "I have been suffering from asthma since the age of 7, and I was recently prescribed montelukast sodium after a bad chest infection, which had me hospitalized. I have taken it previously about two years back as well. However, since I began taking it this time, I noticed I can't fall asleep, I'm badly constipated, and extremely lethargic, depressed, irritable, and get angered really quick. No medicine is worth feeling this way, and I'm stopping this immediately. If a simple drug manifests such tangible changes in your body, imagine what it does to your body silently."

• Ren...
• Taken for 1 to 6 months
• December 13, 2013

For Asthma "I'm 28 and have asthma. I tried Singulair a few years ago, which helped my asthma and allergies. I recently began to have asthma flare-ups again and started taking the generic. This time I am noticing side effects. I have frequent headaches, which may or may not be from the medicine but could be from lack of sleep that I definitely attribute to this medicine. I get so exhausted but can't fall asleep until sometimes 6 a.m., then walk around like a zombie the next day only to repeat the pattern. I am prone to depression but have not noticed it worsening. I am not a crier but now tear up over everything, happy or sad. I have sharp pain in my ears. Dry eyes."

• Hid...
• Taken for 1 to 2 years
• May 26, 2023

Montelukast for Asthma "I was on this for a year with no improvement in my asthma. Two days after getting off of it, I began to have horrific withdrawals, including severe headaches, exhaustion, irritability, weepiness, depression, lightning shocks throughout my body, severe body aches, and inability to sleep. The worst seems to have occurred for 48 hours straight, with no signs of fever or sore throat to indicate flu. After seeing others in forums, it seems to be this medication."

• Fea...
• December 13, 2016

For Asthma "This medication is poison. I don't recommend. My 5-year-old was on this for 3 months when I noticed her behavior changed, a bubbly, happy, and active child had turned into a sad, tearful, tired, and unhappy child, with every little thing making her angry and depressed. I urge anyone who's taking or is thinking of giving this to their child, as soon as you see the littlest change, stop! It can really affect you or your child's life. If only I had researched or my child's doctor had advised me well instead of brushing my worries under the table, I would have never given this to her."

• Jef...
• February 18, 2019

For Asthma "tl;dr version. Montelukast definitely worked as a maintenance medication but had unpleasant side effects after prolonged use. Lifelong asthmatic but for the last 10+ years, my asthma has been under control with Asmanex. Started struggling with allergy-induced asthma late 2018, needing a rescue inhaler multiple times every day. Doctor prescribed montelukast pills in addition to doubling Asmanex, and my issues have definitely dissipated since early January. I went to single Asmanex alongside the montelukast and have been breathing fine. It's far more affordable (~$10/month) compared to the doubled Asmanex (~$50/month), but in the last few weeks, I have been incredibly exhausted and achy. Sleep has been difficult and I feel very mentally clouded. I suffer from anxiety normally, but have not had any symptoms with regard to that. If anything, I'm too exhausted to be anxious."

• Bug...
• Taken for less than 1 month
• January 31, 2021

For Asthma "I've been taking this the last few days, and although it's helped with my allergies and asthma, I am so tired and 'zoney' feeling I'm not sure I want to continue. I feel absolutely exhausted, confused, and really 'out of it.' All I want to do is sleep, which is non-productive, and I can't function like this on a daily basis."

• Bug...
• Taken for less than 1 month
• January 31, 2021

For Asthma "I've been taking this the last few days, and although it's helped with my allergies and asthma, I am so tired and 'zoney' feeling I'm not sure I want to continue. I feel absolutely exhausted, confused, and really 'out of it.' All I want to do is sleep, which is non-productive, and I can't function like this on a daily basis."

• Han...
• Taken for 1 to 6 months
• October 24, 2019

For Allergic Rhinitis "Prescribed this drug after my sinus balloon dilation procedure. I’m 43. Active and fit with a cat allergy. The first few weeks, the drug worked wonders to clear out any post-nasal issues. Loved it. Felt better breathing. By week 6+, noticeable side effects in my mood. Tired, crying, depressed, even suicidal with stress in a short amount of time. Not like myself. I don’t suffer from asthma, so not worth the side effects in my case."

• dan...
• Taken for less than 1 month
• March 23, 2020

For Allergic Rhinitis "After two weeks of using montelukast, I started having really bad nightmares, waking up early, feeling anxious. During the day, I would feel really tired, with pain in my ankles. Some days later, my memory got worse, I started forgetting words, was really slow, it just felt as if my mind was blank and I didn't know how to do basic stuff. I had very strange thoughts, felt really dark and in a bad place. I started feeling really depressed because of this, I was afraid that I'll lose control of myself, became a totally different person. It was then I read this page and started crying when seeing that there were so many that had the same issues. I stopped taking montelukast immediately, now it's been 72 hours off montelukast and I'm feeling almost back to normal. The first day after the medicine was rough, but slowly it got better. Please take this and other users' experiences into account before starting the drug, it should be forbidden to take it."

• jde...
• Taken for less than 1 month
• May 28, 2021

For Allergic Rhinitis "The worst thing I have ever been on. The doctor prescribed me this to make the inflammation go down in my nose since steroid nasal spray didn’t help. It made all of my symptoms so much worse. I then developed nausea, migraines, and tiredness throughout the day. I felt so weak my legs went numb at one point."

• npj...
• Taken for less than 1 month
• June 29, 2021

For Asthma "First of all, this was not the first drug recommended by the pulmonologist since a bout of bronchitis a year and a half ago. I'm very sensitive to most meds. The hope is the benefits outweigh the side effects. Well, they did not for me. Barely lasted three days on this. Heavy nausea and tiredness in the first 24 hours. Yes, that did subside a little, but there were other concerning issues. Nightmares, increasing anxiety, deep negative feeling, increasing stomach issues, increasing asthmatic pressure in the mornings. Pretty sure it made the nose runny, too, because of course it did. Just did not help at all. I just stopped it and pinged the doctor, who agreed. The side effects subsided after about a day."

• Anonymous
• Taken for less than 1 month
• October 1, 2012

Montelukast for Asthma, Maintenance "I've been taking Singulair for three weeks now after going off Advair, which is no longer covered by my insurance. I now have to use a rescue inhaler several times a day and am constantly coughing, feel out of breath, and tired. Maybe three weeks isn't long enough of a trial period. I'm hoping my breathing gets better in the next week, or I'm calling the doctor to try another medication."

• Ros...
• November 13, 2020

For Asthma, Maintenance "On montelukast, I had headaches, restlessness, restless leg, and acid reflux got worse. My whole body ached. Then I started having dreams. It felt like these vivid dreams would last all night. I was falling asleep earlier and waking up later. Sleeping 10+ hours and woke feeling I had not slept at all. The dreams turned into vivid nightmares waking me. I was exhausted. I was in a constant fog, and my brain and body didn't want to function. I stopped montelukast 6 days ago. I don't feel normal yet. Still dreaming and tired, but the dreams are less vivid and not scary. I'm still sore and worn out, and I've had an achy stomach since I stopped, but I'm not sure if it's an effect of this. The only positive is it did help with the asthma, and now that I stopped, I can feel it again. I will take asthma over the effects of this medication any day, though. I am giving a negative rating since the terrible side effects so greatly outweigh the benefits. It completely destroyed my quality of life by the end period of taking this."

• cat...
• Taken for 1 to 6 months
• November 27, 2016

For Asthma, Maintenance "I decided to try Montelukast (generic of Singulair) after a severe bout of cough/flu aggravated by my asthma, which lasted for well over 8 weeks. Initially, I had a very bad headache for at least a week, unabating, and the unusual fatigue and tiredness, regardless of what activity I did. The headache dissipated, but the lethargy has continued, and I never felt like I regained the energy I used to have. So this is very disturbing. I had hoped that after persisting with it for 4-5 months, I would feel better, but I don't. The tiredness pretty much starts almost immediately after I have taken the tablet in the evening. The other thing which is annoying is the stupid, senseless dreams, which I find very hard to wake up from!"

• cat...
• Taken for 1 to 6 months
• November 27, 2016

For Asthma, Maintenance "I decided to try Montelukast (generic of Singulair) after a severe bout of cough/flu aggravated by my asthma, which lasted for well over 8 weeks. Initially, I had a very bad headache for at least a week, unabating, and the unusual fatigue and tiredness, regardless of what activity I did. The headache dissipated, but the lethargy has continued, and I never felt like I regained the energy I used to have. So this is very disturbing. I had hoped that after persisting with it for 4-5 months, I would feel better, but I don't. The tiredness pretty much starts almost immediately after I have taken the tablet in the evening. The other thing which is annoying is the stupid, senseless dreams, which I find very hard to wake up from!"