ADHD - 6 yr old grandson | ADHD Information

When my grandson was 3 he was diagnosed with ADHD and PDD-NOS.  At this end of this summer the took off the PDD-NOS and he only has ADHD which we do believe he's not PDD-NOS.  He was put on meds at that time because he was uncontrollable.  Started pre-school, it was rough at first but when he finished up at 5 this past summer they were amazed at the change in him.  During that time he was on diff meds.  Started with clonidine, adderall and the last up until before Christmas was Abilify.  I went with my daughter to take him to his check up and she discussed some agression issues that he has with his 3-1/2 yr old sister.  Doc said they could up the Abilify to highest dose for his weight or try the cllnidine again because she remembered that it worked at 3 yrs old but he acted like a zombie and they didn't like that.  They weaned him off the Abilify and started him back on the clonidine.  NOT GOOD!  He tells his parents that he doesn't like that bad medicine and his behavior has been horrible.  They took him off it on Friday (he'd only been on it since Monday (4 days) and he's off the wall right now.  Any suggestions?  Daughter would like to try him without but they are both worried about kindergarten.  He's been great there but he was on meds....