I have had some trouble with Afib, but recently had exhausted myself approximately a month ago. I am just getting back to work and had a really bad sinus infection which had my body aching, chills, congested, runny nose, water eyes, gums sore, and sneezing. I took a Walgreens brand cold and pain medicine and later that day took a Alka-Seltzer sinus and cold pill. The next day I woke up and was light headed more than once but went to work anyway. I was at work for about a half hour and then I felt dizzy and sat down, but then a co worker came and saw me and I was sort of passed out. I could hear her asking am I okay? But my face was trembling and I could not see her or respond for apx 15 seconds. The doctors are saying they are be living it is due to the stimulant affects of the ingredient pseudo-ephedrine and/or phenylephrine. What do you think this was really scary?