I can definitely relate with guest #33291 and his experience with Singulair. Except my experience happened on the very first night I took Singulair. Went to doctor for sinus complaints. Gave me a decongestant and suggested I try Singulair since I have chronic sinus, thought maybe I had an asthma component, I guess. Supposed to take it before bed, which I did. After I took it I stayed up for a while and tried to wind down and watched T.V. After a while I, too, started to feel like I was having trouble breathing. Thought maybe it was in my head, stress, etc., and tried to go to sleep but couldn't. The breathing got worse and I felt like someone was sitting on my chest and like a tight band was closing around my throat. It was horrible. Luckily my son takes inhalers so I grabbed one of those which helped but not much. At 4:00 in the morning I found myself in the emergency room. Had to have labs, chest x-ray, steroid shot, iv fluids --- all to just conclude that this was an adverse reaction to the Singulair!! I actually thought I was having a heart attack at the time it happened as I am 34 years old and it was a possibility. I feel like complaining to the company as my free sample of Singulair cost me close to $500 out of pocket in the ER!
Reading some similar situations here leads me to conclude that Singulair is a nasty medication. I know that it works wonders for some, but for me it was horrible. I was actually looking for my 3 year old son. He was on Singulair for almost six months before I was. I had to take him off of it eventually because he was having ADD symptoms, restless and irritability. After experiencing what I did and my heart pounding, now I often wonder if his heart was racing too and feel awful!