I started cephalexin 500 mg for a uti today from my pcp. i only got one dose in this afternoon. i will do 2 times a day starting tomorrow. how long does it take to resolve symptoms or infection? ive been peeing a lot and it burns when pee?

You can take the second dose today; no problem if initial doses are only a few hours apart. Symptoms of lower UTI (cystitis, bladder infection) usually begin to improve about 24 hr after starting treatment and should be gone in 2-3 days. In the meantime, drink lots of fluids to keep urine diluted; and if urgency and pain are severe, ask your doctor about phenazopyridine (Pyridium and generics).