Cipro and other members of the quinolone family may damage your tendons. Some people have reported tendon damage after just one dose.
I take 100mg of Macrodantin once at night and have had only 1 UTI in a year, which was treated with Macrobid (time-released macrodantin). Macrodantin has the benefit of being narrow-sprectrum whereas cipro is broad-spectrum (shot gun approach). Hence, you can take macrodantin for the rest of your life and not have to worry about systemic health issues.