Had culture done of urine and diagnosed with uti.dr gave macrobid. but my kidney hurts and read somewhere that macrobid doesn't treat k.i.what to do?

See your doc: Macrobid is fine for a simple, uncomplicated uti. However, if the infection is spreading to your kidneys, then you need a different antibiotic. However, kidney pain (typically back pain) isn't sufficient to diagnose a kidney infection (pylonephritis) as you could simply be dehydrated. If you have back pain and a fever/chills, see your doc right away.

You are correct: Macrobid, long acting form of Nitrofurantoin macro-crystals is good at sterilizing urine ; treating uncomplicated bladder infections or antibacterial prophylaxis but does not achieve tissue levels needed to treat kidney infections. Flank pain with UTI is a kidney infection until proven otherwise and require a bactericidal antibiotic with good tissue levels, cotact your dr asap to start treatment.