Hi, I find that when I take the daytime cold and flu tablets (the ones with Pseudoephedrine ) make me incredibly drowsy... no matter which brand they are.. Why would that be?? I can barely keep my eyes open and feel horribly heavy. I would have thought that the daytime ones would keep you awake.. I have asked at the pharmacy and the response I was given was ''well , they shouldn't do that''.. um yeah I know that.