Disrespect and learning frustration

Lately my boys especially one of them think that being disrespectful is ok.  No it is not.  My problem I am facing these days is how to deal with this.  He is yelling at me and when he is really upset tries to throw things at me.  Luckily it is short lived but the intensity is there and my frustration shows.  He really does know it isn't me he is mad at but can't seem to make that reach.  He is angry at something at school but comes home and starts yelling at me.  Sometimes I can nail it on the head of what is wrong and then there are times I can't.

I hope with the constant calm reminders and re teaching that it is not appropriate we will get somewhere.  I think upping his meds for aniety didn't help and now we will lower them again and see how things go.  Gosh why can't they make a pill that a child or person can take and it just does the job.