Nitrofurantoin
"I suffered severe headaches & nausea for hours from the very first dose & every dose thereafter. I would feel faint, overheated, extremely tired; I slept with the windows open and the heat off (it's winter). 4 days of taking Macrobid, I begin to have loose stools & severe muscles aches & neck stiffness. I began to have a sore throat & a dry cough on day 2. After stopping, within 24 hours I begin to itch severely. I've been off of it for 48 hours & I still have a headache & I use Benadryl for the itching. I was given Levaquin in 1 dose, then Macrobid 100 mg 2X a day for 10 days by the ER doctor. But my primary doctor thought it was an overkill and should have used just the Levaquin."