help!

My son is 7, and I've literally ran out of punishments. He keeps getting into trouble at school, I've tried taking things away, making him apologize to his teacher, i spanked him, I put him to bed early and took away everything but books. Nothing's worked and he keeps getting into trouble. I realize he's only in 1st grade but it's consistent enough that it's affecting him, and he's interrupting class mates as well. Any one have any advise?