I was prescribed sulfameth/trimethoprim 800/160 for a sinus infection. I was fine until today, the 6th day of taking it. I'm very spacey and feeling floaty. I have a headache. I'm moody. I have no energy. I only have 4 days left but I'm thinking I'll stop the meds today. I'd rather deal with a sinus infection with OTC drugs considering I have 2 small children and the way I feel is NO way to try and function.