Hi, i am a 37 yr old female who was just prescribed norafloxacin for a uti. i took one pill last night and my knee is now swollen and achy and popping - had acl surgery 3 years ago. relation btw 2?

Possible infection: Possible infection. Injured knee more susceptible to infection from blood stream spread of uti. Aspiration of knee joint essential, asap.

Comorbidity: These two or more medical conditions existing simultaneously but independently. It's also called multimorbidity. In your case there is mo relation between 2 conditions. Please see you pcp or orthopedic surgeon to follow up the knee problem.

See below: More likely related to the the previous knee problem.

Maybe: Norfloxacin, and other fluoroquinolones, can have side effects causing tendonitis or inflammation of ligaments in joints. Rarely, they can result in rupture of tendons, usually in teenagers. In this case, i doubt a single dose caused your problem! but to be safe, i would stop the medication and ask your doctor if there is an alternative antibiotic you can take instead.

Needs to be examined: It can't be told, unless examined. Should see your orthopedic surgeon or family physician.