I am 48 and was prescribed Singulair for what is to be believed ...

I am 48 and was prescribed Singulair for what is to be believed as Adult Onset Asthma. Almost immediately after taking it (10 days ago), I have had tremendous leg cramps, constantly in my calves, but at times also in my thighs. I also have had chronic diarrhea and back pain. I have only been off it for one day so I don't know if this all related. I also experience a "full" feeling soon after I start to eat. Scared me silly, I had the common sense to finally read the precautions after feeling very sleepy and seeing my other symptoms could be related. READ THE WARNING PAMPHLET, NOT JUST THE WARNINGS THEY LIST ON THE BOTTLE! I can't stress that enough...