The first time I was given Amoxil was when I was 17 and nothing else would stop me from throwing up. Within a matter of hours after taking ONE tablet I stopped throwing up but became extremely agitated, had trouble breathing, couldn't sit still and this seemed to worsen as it became night time as I'd be lucky to get 2 hrs sleep across 3 nights. I'm now 23 and I fell ill again recently and was again prescribed amoxil-thinking it may not happen again i took it and once again was had insomnia for at least 3-4 days and felt very unstable. At night i will shake for hours. The worst side effect for me by far is the mental state that i go through. My doctor didn't seem to understand how only taking one tablet of amoxil could affect me so severely for such a period of time. After searching for side effects im relieved to know I'm not the only one.