Our 3 year old son took Omnicef starting on a Friday. By Sunday, we were at the end of our rope. He was screaming constantly, we could not get him to go to sleep, he started being VERY aggressive.... kicking growling, hitting and just acting out in ways we'd never seen. My husband finally started looking online after our son had a fit and screamed in a corner of our house for 30 minutes, then looked at us and started laughing and acting like nothing had happened. We found this web site, and to our relief, realized our son was not just acting out. I have NO DOUBT it was the antibiotic and I can't believe this medicine made it onto the market!!! I threw the bottle away and intend to talk to our pediatrician asap.