Recurrent urinary tract infections

[Esmith]

My history of urinary tract infections is a long one. It started when I was about 19 when I got my first real boyfriend and I would get them frequently after sex, about once every two months. It was awful to say the least to experience the burning and frequency. I would be alternately prescribed different antibiotics like Macrobid and Cipro which cleared up my infection (until my next UTI). I also tried my best to wash and pee before and after sex. My doctor then decided getting 3 UTI's in 6 months warranted preventative measures and I was prescribed Nitrofurantoin/Macrobid to be taken as a post-coital prophylaxis. It seemed to help a lot and I haven't gotten a UTI in over a year but I keep hearing about the dangers of bacterias becoming resistant. I definitely don't want that to happen. I'm pretty cautious about my health (to the point where it borders on anxiety) so I've read everything I can find about urinary tract infections. From what I've read nitrofurantoin is the antibiotic that rarely leads to resistance and that studies show post-coital prophylaxis is effective for up to 5 years. I'm just wondering if anyone has any idea on more long-term effects? If I end up having to take this for the rest of my life... will complications arise? Particularly after menopause... My mom also has issues with frequent UTI's and I'm (fairly) sure she doesn't have sex... Will sex related UTI's lead to getting them when I'm post-menopausal even if I don't have sex?

I've read about new treatments including vaccines and probiotic treatments so have hope! In the mean time, I am take the antibiotics and try to void before and after sex. I also want to start with cranberries to prevent getting UTI's. I'd like suggestions on what form to take it in... sugarless cranberry juice, cranberry pills or maybe just eat the fruit itself? What would yield the best results?