As of 3/31/07, I just started to take levaquin. After reading these horrible stories, I'm very concerned for myself. I was on Ketex at three different times this winter. Now I don't know what to do and I'm very scared. Dr. put me on singular and after a few days, I had pressure in the sinses, headache,and upper respiratory problems, for which the Dr. prescribed levaquin. When I read the side effects of singualr (and feeling find before I took it), can alll of these problems be due t the singulair? The Dr. on call who prescribed the levaquin - I asked him if my side effects are due to the singulair? He said most likely not. Now what in the world do I do?