Endometriosis UK

Leukotriene receptor antagonist for endo pain

Found this

Leukotrienes in gynaecology: the hypothetical value of anti-leukotriene therapy in dysmenorrhoea and endometriosis.

The lipoxygenase products (leukotrienes) have been demonstrated in many mammalian tissues including humans. They are widely distributed in the lungs, gut, uterus, kidneys, skin, heart and the liver. Their roles as mediators of inflammation have made them therapeutic targets. Significant amounts of leukotrienes have been demonstrated in the endometrium of women with primary dysmenorrhoea who do not respond to treatment with anti-prostaglandins. Also, in endometriosis, cytokines, which can initiate the cascade for the biosynthesis of leukotrienes, have been shown to be elevated. It is estimated that 10–30% of patients with painful periods fail to respond to prostaglandin (PG) synthetase inhibitors. Of adult females ~40% have painful menstruation and 10% of these are incapacitated for 1–3 days per month, and ~10% of women aged between 15–45 years suffer from endometriosis, which is a significant cause of infertility. Leukotriene receptor antagonists have recently been licensed for the treatment of asthma in the UK. In this review, we present the case for the potential use of these products in the management of primary dysmenorrhoea (especially in patients who are not responding to the traditional treatment using PG synthetase inhibitors) and possibly also in cases of endometriosis.


What do you think?

I have tried loads of NSAIDs with stomach protection tablets and still gets stomach upsets, codines not work very well, tramadol space me out. Hormone treatments are no good to me - tried all sorts of pills, I was told to stop GnRH by doctor with severe side effect. I am still not sure about Marina coil as I have failed with all sorts of hormone treatment and it is difficult to reverse (well by myself).

I will have a lap but not soon enough I guess with this waiting list. At the moment my period hasn't started and I haven't had pain very much. I have a next hospital appointment in the end of June so I am thinking to ask about this research.

Has anyone heard about this? This was updated in 2000. I am trying to find the follow up paper...

12 Replies

This is a really interesting article -thanks.I am going to pass this link to my GP and also my gynae.This may answer a question I have! I have been taking Singulair( Monteleukast) for my asthma for over 10 years now and it has had a remarkable effect in controlling both my asthma,hayfever and allergies.However any time I have my inflammatory markers checked there is always a normal reading,even when my endo is in severe flare.I have often asked if the singulair or indeed my inhaled steroids could be affecting inflammatory marker results and they always say no -which I cant understand at all,if that's what the drugs do!

However I stopped the Singulair last summer, as have been attending a medicinal herbalist,and wanted to try to detox and cut out as many of my 2 page prescription list as I could. I have found my asthma is still controlled without it,but my endo has been in a severe flare since October and is now not responding to Depo Provera.Like you I do not seem to get much relief from codeine based drugs.

I am starting back on the Singulair and will let you know if my endo pain decreases.I am at my wits end with so much pain -hence being up half the night unable to sleep.

Waiting,when you are in such pain is awful isn't it?


Hi Daffodil,

Really interesting. See my reply below. I think this explains why the Monteleukast had an effect on your endo pain. It really annoys me when doctors dismiss a patient's theories as if they know everything.

Hope it produces good results for you again. Sorry to hear you are in so much pain. Take care. x


Hi daffodil, So do you think Singulair was working for your endo pain? I don't have asthma but do you think GP will prescribe to me for my hayfever?

Please do let me know how it goes. I hope it does work for your endo pain too.

Take care,



Hi -well this is the question,as I have been taking Singulair for more than 10yrs and didn't see any link.But reading this article has made me wonder,as the only time my endo has flared uncontrollably has been since last August,when I decided to come off various medications as am seeing a herbalist.I have started them again and will let you know if the pain improves.If this does help( I am in uncontrolled agony since last October and awaiting biopsies after a Ct scan( then this is an amazing discovery.I have been repeatedly given blood tests for inflammatory markers and been told they are fine,so been suggested I have adhesion pain rather than endo,as it should show raised markers.I am at a loss as my body never seems to give the expected results.

Singulair is an expensive drug and is only given for uncontrollable asthma,but it had a remarkable effect on me in being able to cut down on oral steroids and be able to breathe freely again.My asthma is allergic,so it is all linked with other allergies and hayfever.

It is certainly worth a try,if you present you Gp with this info.Depends if Gp is willing to think outside the box.If your hayfever is very bad and in addition you are suffereing great pain with endo -it may be a 2 for 1 solution!

Thanks very much for letting us know about this.I am certainly going to pass this on to my GP will also know if my endo pain improves since going back on them,


Hi Daffodil,

I'm an awful cynic really. When I posted earlier, that sneaky thought crept into my mind...are these leukotriene receptor antagonists too expensive for the nhs? Would they be more expensive than GnRH? Apart from our focus on endo they certainly appear to be preferable to the steroids.

I do hope this works for you on all fronts and gives you some relief. x


I do know that when I was first given a months trial they were £26 for 28tablets but I would think they would have come down in price considerably now.No idea how much gnrh costs.Think it is probably more that research has not filtered through.I have a scientist friend who is trying to patent a new cancer drug and is already into 10th year as so many trials have to be done.Discoveries are made and spend years and years being debated in scientific journals and many get no further as they are *unpopular " fields of study.

I too am very cynical,having family and friends in the medical world and knowing how much is controlled by the big pharmaceutical companies.Im sure a simple pill for endo would be wonderful,but what about all those hormonal treatments ,painkillers we have to keep buying???There are cures in the natural world for cancer,but they are supressed(check out essiac) as what would they do without being able to market chemo drugs.


I totally agree with you Daffodil. I do also think that there is a lot of research out there that has been 'cooked' to make simple cheap remedies appear ineffective.

The fact that it takes so long for research to filter through, if at all, means that this is an opportunity for us as patients to fill that gap. The internet has made this possible.

At the moment I'm not doing too badly. I will observe how things go over the next couple of months and if things get worse or improvement slows I will definitely be demanding these drugs.


Does NHS medication have different price by the area or diseases? If not this could be the price NHS is paying when we get a GnRH.


I hope you can get the medication you want. I will have to make some careful plan soon as I am getting some pains back recently...


Just found this article that outlines a piece of research into the effectiveness of Monteleukast, as mentioned by Daffodil, for reducing endo pain as an alternative to NSAIDs. Promising results. stfm.org/fmhub/fm2004/Janua...

Japan to the rescue Shukudai! Thanks for the info. Very interesting.

I would encourage everybody, especially those with problems taking NSAIDs and codeine to print out this article and question your doctors.


Hi Brownlow

Thank you for finding more link with promising results. I did have told my consultant that I don't respond to NSAIDs and codeine very much and he didn't say anything about the leukorine receptor antagonist. (I found my consultant name on the researcher's list!) I wonder why.

I found a newer study: February 2010 article


Efficacy of montelukast, a leukotriene receptor antagonist, for the treatment of dysmenorrhea: A prospective, double-blind, randomized, placebo-controlled study



To investigate the effectiveness of montelukast, a leukotriene receptor antagonist, in alleviating the symptoms of dysmenorrhea.

Study design

This prospective, double-blind, randomized, placebo-controlled study was comprised of 62 patients with dysmenorrhea who were randomly divided into 2 groups (montelukast and placebo). Data obtained from 50 patients were analyzed (montelukast: 24; placebo: 26). Using visual analog scale (VAS) scores and nonsteroidal anti-inflammatory drug (NSAID) usage per menstrual cycle, values before treatment were compared to average scores over two menstrual cycles with treatment.


Both the VAS scores and NSAID usage decreased significantly in both groups. The decreases were greater in the montelukast group compared to the placebo group, but the differences were not statistically significant. Nevertheless, in “highly effective cases,” which were defined as having a post-treatment value less than half of the pre-treatment value, the decreases were significantly greater in the montelukast group than in the placebo group (VAS: montelukast, 4 vs. placebo, 0 (P = 0.029); NSAID: montelukast, 9 vs. placebo, 3 (P = 0.031)).


The present study found that montelukast may be effective in alleviating pain associated with dysmenorrhea in some women. Montelukast is safe and does not influence hormonal levels. Therefore, montelukast is a clinically reasonable management option to consider before prescribing a hormonal agent.

Why didn't I even get to try Montelukast before GnRH? The injections have more drastic than Montelukast, I think.


Yes, that's the same team behind the initial study that I linked to so at least they know there was sufficient merit in the idea to examine further. I can get the full text for you if you want.

I have learnt that there's a huge gap between the results of research and actual implementation. Often it's pure chance that doctors pick up on useful results by way of an industry magazine. It also takes a long time for new results to find their way into the recommended treatment pathways and reach a doctor by that route. But what I don't understand is why your doctor didn't recommend this given his apparent knowledge. Very odd. Also, this is potentially such a simple solution that GPs can even prescribe this. The internet is really changing things in many different aspects of our lives and our healthcare should be no different. The days of accepting every word our doctors say are going.

GnRH have no place in the treatment of endo in my opinion. I think they are a huge gamble and simply not worth it. Their only possible use would be in preparation for an operation to reduce the endo and thereby reduce the risks. But still questionable.

I also have bad hayfever which has got worse in tandem with my endo. I don't like taking NSAIDs because of the longterm consequences and they don't always work. Try going to your GP with the 2010 research printed out and explain about your 'debilitating' (best to exaggerate!) hayfever and ask to be put on Monteleukast. Maybe print out the overview article that I linked to as well. It lists the different drugs and also covers possible side effects. Your GP might be too chicken to prescribe in which case you need to demand for referral on to your specialist....or change GP.

Let us know how you get on and thank you for sharing this really promising information. Well done for finding it. x


Additionally, leukotriene receptor antagonists (Monteleukast) seems to be effective in treating interstitial cystitis, IC with a recommendation for more clinical research to confirm. ncbi.nlm.nih.gov/pubmed/115...

IC is often concurrent with endo.

This article gives a good overview of leukotriene receptor antagonists. annclinlabsci.org/content/3... It mentions its usefulness for treating IC.

This would appear to be a novel and viable way of treating pain symptoms associated with endo and also IC. As always, there are some potential side effects.


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