How long to get Bactrim completely out of the system

I stopped taking it on July 10 and only took it for 3 days and today is July 19 and I still have itching, hives and sever chest pains.

I am no expert but I would say months. Reason being I was bitten by a dog in 2005 and Bactrim was one of the two antibiotcs I was perscribed. 6- 9 months later I still was suffering from all the side effects of that round of antibiotics. I was perscribed this aweful antibiotic again and am suffering worse side effects then the first time. I will be closely monitoring all my symptoms this time. I will never take this horrible drug again. My suggestion go to a health food store and buy multi fiber/herb supplements that will cleanse your system and try to remove the harmful stuff out of your system while you replenish the good. I will be starting that treatment myself in a day or two.