I recently found out that I am allergic to Sulfa drugs (Bactrim DS is one of them) while being treated for a UTI. One of my many
side effects early on was severe lower back
pain, flu-like symtoms that included sweats, achiness, joint pain, abdominal pain, rash on legs and a ton of other symptoms.. I only took it for 3 1/2 days, but paid for it for 5 wks after taking it. In my opinion it is a horrible drug. I could barely get out of bed during those 5wks the joint pain was so horrible.