anger explosions and antibiotics?

My son is adopted from foster care and was for sure cocaine-exposed, had hypertone, and has always been challenging behaviorally. He is now 6. The problem is, he's big and strong, and I'm small. I can no longer continue to restrain him when he's having a tantrum. He's usually sweet and loving. However, sometimes, if he doesn't get his way, it's like a switch flips inside of him and he loses self-control. The thing is, he can hold himself together at school (which is only half-day). He's been on antibiotic for his ears, and antibiotic definitely makes it worse. I ask the drs not to prescribe it unless he really needs it. I even asked for dye-free this time hoping that would help. I just assumed that some kids can't handle antibiotics, but as I have mentioned it to others and to a nurse, they have never heard of antibiotics causing that extreme of a reaction in a child. So, I'm now guessing it has something to do with his drug exposure. Has anyone else noticed this antibiotic reaction in their kids? How do you handle it?