Log in
Asthma UK community forum
12,856 members18,484 posts

Singulair - side effects

Hi all,

I started Singulair on Wednesday evening and have had upset stomach and headache since yesterday lunchtime, I've had a look at the leaflet and these are common side effects. My question is...are they likely to go away and if so how long might it take for the side effects to go away or are they likely to be permanent? I wasn't able to take Uniphyllin because of side effects and am a bit concerned that it might prove to be the same with this. Anyone got any advice on how long to persist with it before seeing GP and asking to stop meds?

30 Replies

Just call me Tigger.

Hi Feejay,

No upset stomach for me. What I do have is extreme wakefulness. I'd asked pharmacist about main side effects ie stomach upsets etc. They suggested take the tablet after 6 pm perhaps at tea-time to offset any indigestion or upsets. I've been doing that which is ok as far as my insides are concerned, but finding I'm SO AWAKE. Feel I'm bouncing off the walls when I should be sleeping.

I get vivid dreams at the best of times and was a bit worried about this listed side effect. As it turns out, I'd no need to worry about a night filled with ever more vivid dreams - cos I don't nod off until about 4 in the morning.

I've tried listening to all the meditation programmes on my i-Pod but doesn't work this time.

Its only been a few days so far, giving it a week to settle down, hopefully. My next review is in four weeks time - here's hoping I've had some sleep by then. Here's hoping too, your symptoms, FeeJay, have settled long before then.


Hi Tigger

Poor you! I slept well last night except that the headache woke me up every hour or so. Weird medication huh!?

Hopefully the side effects do wear off.....I can't keep rushing to the loo!!

(Tigger......Winnie the....)!!!!!! Sorry - couldn't resist the bad pun :oD

Take care Granny!


Undesirable effects

Montelukast has been evaluated in clinical studies as follows:

• 10 mg film-coated tablets in approximately 4000 adult asthmatic patients 15 years of age and older.

• 10 mg film-coated tablets in approximately 400 adult asthmatic patients with seasonal allergic rhinitis 15 years of age and older.

• 5 mg chewable tablets in approximately 1750 paediatric asthmatic patients 6 to 14 years of age.

The following drug-related adverse reactions in clinical studies were reported commonly (GREATER-THAN OR EQUAL TO (8805)1/100 to <1/10) in asthmatic patients treated with montelukast and at a greater incidence than in patients treated with placebo:

In Adult patients 15 and over, two 12 week studies; n=795 = headache, abdominal pain

In Paediatric patients 6 to 14 years old, one 8 week study; n=201 and two 56 week studies; n=615. == headache

With prolonged treatment in clinical trials with a limited number of patients for up to 2 years for adults, and up to 12 months for paediatric patients 6 to 14 years of age, the safety profile did not change.

The following adverse reactions have been reported in post-marketing use:

Blood and lymphatic system disorders: increased bleeding tendency.

Immune system disorders: hypersensitivity reactions including anaphylaxis, hepatic eosinophilic infiltration.

Psychiatric disorders: dream abnormalities including nightmares, hallucinations, insomnia, irritability, anxiety, restlessness, agitation including aggressive behaviour, tremor, depression, suicidal thinking and behaviour (suicidality) in very rare cases.

Nervous system disorders: dizziness drowsiness, paraesthesia/hypoesthesia, seizure.

Cardiac disorders: palpitations.

Respiratory, thoracic and mediastinal disorders: epistaxis

Gastro-intestinal disorders: diarrhoea, dry mouth, dyspepsia, nausea, vomiting.

Hepatobiliary disorders: elevated levels of serum transaminases (ALT, AST), cholestatic hepatitis

Skin and subcutaneous tissue disorders: angiooedema, bruising, urticaria, pruritus, rash, erythema nodosum.

Musculoskeletal and connective tissue disorders: arthralgia, myalgia including muscle cramps.

General disorders and administration site conditions: asthenia/fatigue, malaise, oedema, pyrexia.

Very rare cases of Churg-Strauss Syndrome (CSS) have been reported during montelukast treatment in asthmatic patients

I've emailed you both a full PDF doc.



Hi guys

i have ben taking Singulair for about 4 years or more and i can truthfully say that the side effects do wear off. Persevere with it. I now have my asthma almost fully controlled. i still get the odd attack which is both scary and bad. the last one saw me in A&E with heart attack symptoms and he weirdest heart tracings my GP has ever seen.

BTW I also have ME and Fibromyalgia.


Saturday night's nightmare had me sitting up for far longer than usual last night until DH said its a bit daft to put off the sleep we both need in case of imaginary fears. Unwillingly, I went to bed.

The i-Pod didn't have me nodding so I took it off. Thinking of blue skies and sunshiney days didn't send me off either and when I eventually fell asleep, I'd a series of bad dreams in which I seemed to be trying to catch up with people at work who were walking ahead of me/ caravan being towed away by someone unknown - kept catching sight of it at ends of roads/running to catch shops before they closed.

I see what husband means by imaginary fears cos -

I don't work so don't know what the first was all about, Secondly, caravan is well secured, insured and one or other neighbour always pops out when we're out for anything from it. Thirdly, we have a 24 hour Tesco and 24 hour Asda not far from house.

Not noticed much difference in peak flow as yet - still running at 65%. Nor any difference in coughing when eating chocolate or coming in from the cold outside to a warm place. But then, its not even a full week yet. Will persevere for the month as set by ashtma nurse. Looked back over reliever use per week over past few months (yes, couldn't help myself, I did a spreadsheet. LOL) and any improvement would be a bonus.

Best wishes to all who are struggling or have struggled with Singulair. Thanks pageantqueen, for the encouragement too.



Granny Mo

Although Singulair has helped me, it seems to only help my symptoms at night time (I didn't sleep for months due to constant coughing anc choking/asthma attacks at night)

I too still get problems during the day, especially in winter when coming in from cold air and going into coughing fits etc. i dont know if then Singulair is maybe only good at helping night time asthma symptoms?

I have been getting very vivid nightmares lately but i dont think it is the Singulair as I have been on these nearly a year now and this has only started recently


Hmmmm, interesting. My tummy issues have pretty much resolved but I too am having very vivid dreams. They are not horrible, just vivid enough to wake me. It makes a change to waking feeling suffocated but still...it would be nice to sleep for a whole night for once!

Nice to hear other peoples experiences,

Hope things improve for you GrannyMo

Edit: Had to go in to edit some AWFUL spelling mistakes! Lol.


Singulair, once it had had a chance to work, worked really well for me, firstly clearing up night-time symptoms so I could get a full night's sleep which was wonderful (I never had problems with vivid dreams - well not that I could specifically attribute to Singulair anyway), but then most importantly really helping with my EIA to the extent that I was even considering finishing off my Three-Peaks Challenge (I'm aiming for the record books for the longest time taken to complete - I'm two-thirds of the way there!! and the extra time means I collect more sponsorship for each - cunning, huh?). I haven't made it yet, but I did manage some other hill walking a few months ago until everything went wrong again.

It seems for me that when my asthma's not so bad, Singulair is fantastic and gives me a massive boost, but when my asthma is bad and especially when I'm on the high Pred it can't compensate.

BTW, I'm interested that some of you mention difficulties coming in from the cold - I get the symptoms you mention when I go outside from warm to cold which isn't great when I love the outdoors :(


Hi all,

My gp prescribed me singulair last tuesday, after two courses of steriods and two courses of antibiotics along with symbicort over a five week period.

Gp advised me to take just before bed, managed a really good night sleep and felt much better wednesday morning, though cough is still persistent but no longer feel as though I've an elephant on my chest.

Only side effect (if it is a side effect) I've noticed is extreme sickness, I felt dreadful all day friday and started vomitting late friday night which carried on over the weekend and even today the nasaeu is still persistenting - has anyone else had this as a side effect?

I'm pretty sure it's not a stomach bug as neither my husband or my son have been ill or are mentioning feeling unwell.



I felt very sick and had diarrhoea and vomiting for 24 hours and then just felt really sick from Thursday (started singulair on Weds evening) which gradually wore off over the weeekend.

That has pretty much worn off now and am just having the weird sleep disruptions.

Keep us posted with how you get on!



weird or what but Fee, GM and PamPam all have these dreams, and only connection - scotish, now what are the odds of that.

Pam, I assume you're a scot, and not moved their.


Must be our celtic heritage :oD


Woody youassume correctly!

Maybe its an inbuilt Scottish thing to keep our minds off the crap weather for a bit!!

I've been putting my vivid nightmares down to being really run down and ill on and off for most of this year. Dont really know why i put it down to this though?


don't assume you have all the crap weather, freezing cold and foggy down near the south coast all day. Wonder if it's the female mind, constantly thinking , male minds are so small they need a rest :) (last bit a joke BTW)


Don't worry Woody, i work with a few males and I understand their minds have limits :P

Joking aside I think being unable to turn off and stop my mind working at night is partly my problem!


pampam, you may be correct about shutting your mind down. I know in yoga you are told to clear your mind, but a yoga instructor told me she prefers the term 'calm your mind' as the majority of people can't clear their minds in her experience.

mines empty so not much trouble clearing it LOL


I try everything to get all relaxed before bed and the really annoying thing is im really tired before i go to bed! lol

I read a lot before bed and sometimes it does help to tire me out but maybe its giving me fuel for my nightmares as i read a lot of history books and historical fiction which can be quite gruesome and violent :p

Only thing thats been getting me to sleep lately is the strong painkillers i got for the lung pain from having flu. Think this pain is what keeps me awake a lot. Was going to go to the doc about it but got flu 2 days before my appointment and my chest is clear of infection now aswell which is all they seem to look for! Just know if i go and say about the pain just now they will say its post-flu pain


looked at research papers, and can't find one specifically but a study was carried out on sleep disorders in children, and certain medications and reasons were given for this. montelukast was listed as one med.

However factors such as lifestyle, TV, internet, stress etc may also be to blame



Bad dreams KO'd

Cracked it. As far as my own sleep is concerned. Singulair taken at 7pm with tea. Little light supper at 11pm. Bed by 1am, earphones in, PInk Floyd's Dark Side of the Moon on i-Pod - woke at 9 am perfectly refreshed.


Well done Grannymo!

I'm still having problems with vivid dreams although they do seem to be settling a little (either that or I'm getting used to them!) but I am still waking early :o(

Will try a warm drink before bed tonight and see if that helps.

Pam, I know what you mean about mind in overdrive, I try to read mindless stuff at bedtime to switch off but it doesn't always work. I have to say that stress always does give me sleepless nights so I'm probably quite susceptible to sleeplessness.


Thanks Feejay.

Given the other side effects mentioned in the med. leaflet, I did wonder if this was the right album to chose.

To me, though, it gives many happy memories of first year of married life. Friends round we'd listen at pretty well full blast in our top floor, three room and kitchen tenement flat with its 12 foot ceilings. Instead of buying the washing machine my mum thought we were out for that weekend, we'd bought a very good stereo. LOL


PS A year on, workmate gave us their older twin tub washing machine. My mum was happy until the weekend we swapped it for a piano.


Nice one GM,

Excerpt from medical news today. - Women With Asthma Feel Worse

Women with asthma are more anxious, find it harder to sleep and are more tired during the day than their male counterparts, tinyurl.com/yapdkxf


Interesting Woody. Would like to know more about the throw away line in there where they posit that adult women may suffer from a different type of asthma. Will have a look and see if I can find any more info on that.

GM, made me laugh :o) Love the washing machine for piano......bet your mum was livid!



Fee, something to do with the monthly hormonal shift I suspect, It has a huge impact on some womens asthma. Found this today tinyurl.com/ycemyr7


Fee, late night reading.






While none of the links are conclusive, there is definitely a hormonal link, that isn't present in males.


Lol!! Yes thanks for that Woody!

I have just had a letter from my consultant which says I have atopic brittle asthma - weird.



weird, never thought you were that bad.

brittle asthma in adults comes in two types: type 1, showing more than 40% diurnal variability in PEF rate on most days over long periods and type 2, with acute severe attacks (often sudden) on a background of apparently good asthma control.

Adults with brittle asthma are generally atopic, An allergic reaction that becomes apparent in a sensitized person only minutes after contact, does that sound like you?


Ooh yeah. So that's what it means! Duh - I thought it meant atypical!

Yes, if anyone sprays something like deodorant near me or walks past with strong perfume I have an attack, similarly pollens and stuff set me off. Also, when I go downhill I can go down really fast, PF can drop from 400 to below 50 and me needing vented in about 20 minutes.

Not pleasant!

That explains why he wants to get me allergy tested.

Thanks for the info Woody - where would I be without your mine of information!

I'm feeling really grotty and depressed today.....got any good jokes?



thanks, but some of the credit has to go to kitkat for that.



is singulair suppose to make u feel knocked out like a sleeping tablet? when i take it it generally makes me sleep for an hour r 2 then i wake up just to go back to sleep much later x


You may also like...