it depends on the bacteria that is causing the urinary tract infection. penicillin is not the preferred drug that is used for utis since it usually is not sensitive to the common bacteria usually bacteria that normally live in the colon (enteric bacteria). i have never treated a uti with penicillin. penicillin works great for strep so if the uti is caused by strep it could help but most of the time utis are other types of organisms that are resistant to plain 'ol penicillin. i am assuming you have not had a urinalysis or a urine culture. if you are self-diagnosing and self-treating a uti with an old prescription of penicillin i would strongly caution you against doing this. utis can quickly get out of hand if treated improperly and could end up involving the kidneys. diagnosing and treating a uti is best left up to a medical professional.
will penicilen cure an uti?