Metronidazole
"I have only just started taking the metronidazole with doxycycline 2 days ago and I already am in so much pain. My head is throbbing and I can feel the pulses, my ears have been aching, I feel so faint when I get up, I cannot sleep, eating is okay but I have barely eaten and when I do it makes me feel sick. On top of all this I have been going to the bathroom every minute to pee, and after I pee I feel like I need to pee again. My urethra  become so sensitive after I pee and it feels, like I said before, as though I need to pee again. I get hot flashes and had a temperature all day yeaterday and just last night I was freezing and slept with a jumper and covered my entire body with my blanket, even though the city I live in is hot"