I use the Montelukast sodium, the drug is called "Singulair" in most parts of the world. Although I'm not asthmatic, I have "alergic renitis" which makes it difficult to breath when you are exposed to things you are alergic to. Singulair is a pill that you take once daily and it opens your lungs and prevents asthma attacks. Montelukast sodium was discovered in the MRL laboratories of Merck (MSD) located in Great Britain.
I discovered Singulair when I started working for Merck & Co. the owner of the patent and the manufacturer and distributor of the drug. First I didn´t want to change from Claritin D to Singulair, because my doctor didn't know Singulair, but I went to another doctor, he prescribed me Singulair and it worked really well.
Anyway, if you want to know more about Singulair, try talking with your doctor, he will evaluate your condition and give you the best advice. You can also find more on our global website: