Is this right?

Christian started his medication yesterday.  He will take one pill in the morning and it slowly releases the meds throughout the day.  Common side effects include headache, stomach ache, trouble sleeping, decreased appetite, nervousness and dizziness.  Christian took the pill with his breakfast but then decided that he wasn't hungry and couldn't eat anymore.  He had eaten about half of his bowl of cereal by that point.  I took him to school anxious to see how he was after school.  I was very surprised.  Christian was very calm.  I had a fast food bag in the car and he said "mom, if you have an extra taco, I don't want it".  I started asking questions.  He said that he ate 1 chicken nugget at school for lunch.  I asked how he was feeling and he said that he was feeling different.  He had Sylvan after school and I usually make him a snack to take with him.  He did end up eating a cheeseburger at that point.  When I picked him up from Sylvan he said "can I go home, sit on the couch and watch cartoons?"  He didn't have any homework so that was fine.  Christian sat curled up on the couch watching cartoons while Ayden went about his normal antics trying to get Christian to bite the bait.  Christian barely even had a reaction.  Normally he would be chasing Ayden away, pushing, shoving etc.  

At bedtime I told Christian that I wanted him not to read because he said he was feeling tired.  He went straight to sleep.  At 5:30 this morning he woke me up saying that he was having problems sleeping.  I asked him if he was reading in bed, he said no.  He wanted to use the bathroom before he went back to bed.  Christian threw up and had diarrhea.  Once he was done with all of that, he wanted to sleep on the couch.  He went right back to sleep and I let him sleep until 8am.  

I intend to keep a very close eye on Christian this weekend while he's home with me.  If I am still concerned then I will contact his doctor on Monday.  I really wasn't expecting to see such drastic changes.