I am prone to getting uti's. I usally take cipro with no side effects and goes away with in 2 days. I went to a different dr. this time and she prescribed my bactrim. I cant believe this drug is still on the market. The first day i was fine, the second day i woke up with a major headache. I ignored cause at the time i didn't know it was from this medication. As the days went on the headache was still there and nothing seem to help it. I stared becoming dizzy all the time. On the third or forth day i became violently ill. Fever, chills, throwing up, dizzy, my entire body was sore and could not get rid of this headache. It last for about a week. When i went back to see the doctor. She told me it wasn't from the drug. I KNOW IT WAS!!! It wasn't until my husband did some research on this drug and found out i was having a allergic reaction to the bactrim. I will never take this medication again and believe it should be taken off the market.