I was taking amoxicillin and pain medication for a toothache. That tooth had been root-canaled years earlier, but had deteriorated and was extracted. Meanwhile, my cat bite me severely puncturing skin and infection began immediately. The antibiotic was switched to augmentin, then after tooth extraction back, back to amoxcillin.....now 2 weeks later I have extreme fatigue, weakness. My dr says it is toprol xl and unrelated to aforemention. I'm don't know.