I was given Bactrim at the ER where I was diagnosed with a staph infection. They gave me 800 mg twice a day for 7 days. On day 8 I returned to my regular GP because another boil had appeared. He said the dosage the ER had me on was not high enough. He doubled me to 3200 mg a day. After 4 days on this high dose I began to feel terrible, flu like symptoms, all of my lymph nodes were swollen and painful to the touch, especially the ones at the base of your neck/head. That night my eyes started itching like crazy and began to swell. I went back to the doctor she said it was allergies in my eyes and prescribed some expensive drops, told me I had a virus causing my body aches and fever, and lanced my other boil, she then put me on Doxycycline. That night I broke out in a terrible rash from head to toe that was itchy, then became more like a very painful sunburn. I thought I was allergic to the Doxycycline, so I called the doctor who switched me to Levaquin, wow,,,I sure have spent a lot of money on medicines to discover tonight on this forum that all of this was due to Bactrim. I will NEVER take it again as long as I live.