I am taking a course of antibiotics for uti .but i still have the burning sensation after urination and back pain in kidney area .?

Go back to doctor: Several possible explanations, but would need more history, exam and labs before venturing a guess. The organism may not be affected by the antibiotic you are on, you may have a more extensive problem than a simple cystitis, which could include anatomic variants, stones, tumors. You need a full evaluation. Good luck and get better soon.

Need urine re-tested: U may still have an active uti. Antibiotics u r taking may not be effective against the bacteria causing your UTI so u may need to be on a different antibiotic. Back pain means possible kidney involvement, pyelonephritis, which needs to be looked into. You probably need a kidney ultrasound. Urologist or nephrologist might also recommend other studies.