keflex is terrible. took 500g 3x a day but only lasted two days i...

keflex is terrible. took 500g 3x a day but only lasted two days instead of a week (and using the repeat i was prescribed) for my throat infection. it basically knocked me out for the two days i was on it, also experienced extreme nausea and some lower back pain...have now switched to amoxil after talking to my doctor and am feeling much better....won't be taking keflex again. i wonder if there are people who have taken it without any side effects.....