Last February, which is Mountain Cedar Season in Texas, my doctor put me on Singulair. All was well for a couple of weeks and then I started experiencing an inability to focus for long periods of time, was anxious, nervous, depressed, and passed out one evening while in a heated discussion with my son. I was also eperiencing rapid and at times hard heart beat, and while at a clinic for a leg injury, had high blood pressure (which has never been a problem).
Fortunately, I found this website and read another persons posting that was experiencing most of my symtpons. I immediately went of the singulair and within a few weeks was back to my normal self.