I have been taking singulair for runny nose from allergies. I nev...

I have been taking singulair for runny nose from allergies. I never thought the drug was causing side effects but I an having many of the side effects described by other users of this drug. Vivid, weird dreams, extremely tired all the time, leg cramps, thinning hair, blurred vision, depression. I can't believe how many infants and children take this drug. It really didn't help my runny nose. My MD says there are NO side effects from this drug. I think I disagree.