I went to the clinic with a severe urinary tract infection. I was prescribed 500 mg Levaquin for 5 days and started taking it immediately (if you've ever had a UTI, you will understand!) I woke up on the 3rd day and could not move my fingers - my entire hand ached and was so stiff. It began to progress down to my elbows. I recieved a call later that day from the clinic saying they had prescribed me the wrong drug...a culture proved a different bacteria to be the culprit. Apparently the Levaquin was fighting nothing in my body besides my hand! I thought the pain was from the UTI going untreated for so long, but now I can see it was obviously the Levaquin. I still feel stiffness in my hands every morning, but it goes away and I am able to function. But I find it incredible that taking a prescribed medicine can affect me daily...and this was around 3 months ago that I took it!