I started Singulair in the spring of '05, when my pollen, dust an...

I started Singulair in the spring of '05, when my pollen, dust and cat allergies were causing my asthma to really flare. It worked amazingly well, though I have not taken any other prescription asthma meds to compare it to. Then after a couple of months I started noticing the muscles in my legs feeling very tight. I started getting cramps when I went running, which never happened before. Then I got cramps in bed at night. One day, I squatted down to get something and the tight muscle in my quad made a popping sound and I couldn't get up without great pain. I went to the doctor and it turned out I had torn a muscle. I ended up having three months of physical therapy, and that muscle still hurts a little bit even now, nine months later. I never had bad muscle tightness or cramping before I went on Singulair. Also, I did notice myself becoming more irritable and angry--and so did my husband. I stopped taking it, and the cramps and anger went away. Of course, the congestion and asthma returned, but that's better than what was happening. Bad stuff!