I have a history of recurrent UTI's and protatitis and finally went to a urologist for an opinion and treatment. I am 67 years old and have retrograde ejaculations during sex. He believes that residual bacteria in my prostate is retrograding back into my bladder when I ejaculate causing the UTI's. We shower before sex so I did not believe it was in anyway a hygiene issue even with the retrograde. All this stated, he placed me on a month's regimen of cipro and instructed me to take one Mono-100 MCR tablet of nitrofurantoin just prior or after sex (after my cipro course was completed) going forward. We have sex about twice a week. My concern is taking an antibiotic sporadically just a couple times a week. I have always thought that antibiotics need to be taken full term to make certain any bacteria does not become resistant to the antibiotic. Does taking it on a situational basis put me at risk in anyway? Thank you in advance for your opinion.