urinary tract infection
"I'm taking nifurantoin (Macrobid) 100mg, currently on day 4 of 7 for urinary tract infection (UTI).  My urinary tract infection was more than painful pee - I had the whole set of flu-like symptoms like chills, nausea, aches and of course, painful pee and blood in the urine.  I would say about 80% of my symptoms - especially the pain! - was gone within 24 hours and the only thing I feel now is a bit of itchiness in the urethra when I pee. No big deal.

On the down side, I am VERY tired (day 2 was the worst, felt like I was 90 years old), a bit dizzy, certainly nauseous, I feel like I have to breathe really hard and muscle pain. 

Overall, very effective for treating urinary tract infection but I feel like crap and I can't wait to finish the 7-day course."