urinary tract infection
"I've taken antibiotics many times before in my life, but with nitrofurantoin I experienced really bad headaches after day one. Quit taking them for 48 hrs, headache cleared rapidly, then recommenced course..same again..very bad headaches, energy loss, feeling very weak and nauseous.. have ceased now and feel better again. Now I just have to clear up my UTI ! Yes reaction to antibiotic far worse than UTI. Be wary of this one, though everyone's different."