asthma
"I took Singulair for a week because I was having trouble with my asthma and allergies. But I also have anxiety and panic attacks often and Singulair made it so much worse!! Every time I took it my heart would race and even the next morning I would still have a racing heart. I ended up having panic attacks every day and going to the ER twice in a week while on this. I will NEVER take this again, it's very bad for people who have anxiety. My asthma is still bad but it wasn't worth trying because of the side effects."