A patient who is allergic to cats tells you that she took a…

A patient who is allergic to cats tells you that she took a her montelukast sodium (Singulair) before going over to a friend’s house to study for the night because she knew her friend had a cat.  She went on to say, ” I was still sneezing constantly and a complete watery-eyed mess! That Singulair did nothing for me! ”  What is your assessment of the situation?