Does amoxicillin cause hyperactivity in anyone else's child? My 8 month is on it now for an ear infection and after every dose she acts like a crazy baby. I give it to her after breakfast and dinner so she has food in her tummy and when I go to put her down for a nap or to bed shortly after, she acts crazy. Back arching, noodling off my lap, swinging her arms and grabbing whatever she can reach, banging her head into my chest, sitting up and slamming herself back down - the only way I can describe is that she's acting extremely hyper. I know her stomach is bothering her (she's on a probiotic to address) but I have no idea what the deal with this is.