Hey all,
I was wondering if anyone could explain the use of this or why someone with Asthma would get it. When i switched my phone on after work I had a voicemail form my Asthma nurse saying they had discussed my Asthma and thought this could help and if i could go and collect the prescription. So I have but i'm not sure why.
Laurenjayne
Hi Laurenjayne,
Montelukast or Singulair is a tablet medication that is taken once a day, usually at night, all the time for the prevention of asthma symptoms. It is not a short term reliever medication and has no documented effect in an acute attack.
The drug is an example of one of the leukotriene receptor antagonists (the other main one being zarfirlukast or Accolate). Leukotrienes are specific chemicals in the body that are involved in inflammation or what is known as the 'inflammatory cascade' - there are many tens if not hundreds of chemical mediators involved in inflammation that currently known about in the body, and the leukotrienes are just a small subsection of these. They are produced by the body in response to a trigger such as an allergen, and act on the cells of the airways to produce inflammation and narrowing and thus asthmatic symptoms
Montelukast works by binding to the receptors on the cells of the airways, and blocking them so that the leukotrienes cannot then bind. You can think of it a bit like putting chewing gum into a lock (the receptor) so that the 'key' (the leukotriene) can't be used. So the idea is that the airways cannot then respond to the leukotrienes by becoming inflammed.
Sounds fantastic, doesn't it? The problem is that as I said, there are hundreds of chemicals involved in inflammation, and the leukotrienes represent only a small number of these. There is no doubt that these drugs work very well in a proportion of asthmatics - particularly those with predominantly allergic or exercise induced asthma, which is often presumably largely mediated by leukotrienes. For other people, these drugs will give them some help, and for others, they are no help at all. This is because asthma is likely to be caused by different inflammatory chemicals in different people, and these drugs target only this one very specific subgroup of chemicals (as opposed to steroids, for example, which have more of a 'sledgehammer' effect, damping down a wide range of the different inflammatory chemicals, and therefore proving effective in a greater number of people - but causing more side effects too).
As I have said, these drugs are particularly effective in those with allergic or exercise induced asthma. They can also be very useful in people who have Samter's triad of nasal polyps, aspirin sensitivity and asthma (and usually rhinitis too) - as the leukotrienes tend to be the chemicals that drive this reaction. Leukotriene receptor blockers can also be helpful in hayfever and other types of allergic rhinitis.
Like any drug, there can be side effects - the main ones people seem to complain of are headache, abdominal pain, restlessness and difficulty sleeping. These are usually fairly mild but can occasionally be bad, although they do improve as you get used to the drug so it is important to bear with it if you can. Of course, if you are really concerned about side effects you should talk to your doctor. Most people seem to tolerate the drug without major issues.
It takes a few days to get the maximum effect from these drugs, so do bear with it if you don't see an improvement straight away. A lot of people do find these drugs extremely useful, especially for improving the quality of sleep, so I very much hope that you will too, Laurenjayne.
You can find the BNF entry for montelukast here: bnf.org/bnf/bnf/53/129220.htm (requires registration, but is free and quick).
You can find more info together with some useful asthma management tools at singulair.com - but bear in mind that this site is written and run by the drug company that make Singulair, so it is not an unbiased assessment, although it should be factually correct.
Hope this helps,
Em H
Thanks for a long and detailed explanatoin!!
THat is a lot better than the info on the leaflet!!
I'm going to start them tonight and hopefully the side-effects don't bother me - although I wouln't be surprised if they do obviously i'll wait, see an persevere.
Hopefully it brings some relief.
Laurenjayne xx
prenisolone and asthma attacks 
Poor care at GP practice
animia
