Nitrofurantoin
urinary tract infection
"I took this for a bladder infection. It took 24 hours for me to notice any improvement. I am on day 4. I had 20 minutes of mild nausea one day, but that was the only side effect. Not as bad as others, like doxycycline. Surprised to find this didn't make my yeast infection come back, or cause any other unpleasant side effects."