Nitrofurantoin
"I get a couple UTI's a year. I always take Macrobid. If I take 10-20 billion probiotics 2 hours after taking the Macrobid, I'm fine. No yeast infections or nausea. You must replenish your flora after each pill. It is a must! When I didn't, I used to have all the bad symptoms you read about. Even after my course is done I continue to take the probiotics for another week or more."