Which is better at preventing recurrent utis- hiprex or low dose antibiotics?

Good question but none should be used, especially in adult, because sooner or later resistant organism will emerge.

There has been no head to head prospective study. Both work in some patients and not in others. Antibiotics can sometimes upset the normal colonic flora. Best under care of your Urologist. Add to that- local hygiene, regular BM, plenty of water and emptying the bladder on urge and after sex. Good luck