Montelukast
"I"ve taken both Singulair and Montekulast.  The first time I took Singular, several years ago, I had nightmares filled with horror.  I quit taking it.  I now take montekulast and still have unusual and eerie dreams, but they are not full of the horror of those of several years ago.  I also find it difficult to sleep more than a few hours at a time, partially because of the dreams, which waken me.
However, it controls the night coughing better than any other drug I've used, from prednisone to advair.  I will continue to take it unless the side effects worsen."