My son started Strattera last Monday also! He was doing well on Ritalin but his doc felt we needed to try Strattera to see if he has less side effects than on Ritalin so we're giving it a try.
He's only 4 (almost 5) so she started him on 10mg. Then a few days later he went up to 20mg. We're going up to 30mg in a few days. And yes it makes him fall asleep! My son NEVER just falls alseep during the day but one day he just put his head in my lap on the couch and fell asleep! Kinda freaked me out! The doc said it's normal and should go away as the body adjusts. I notice he gets sleepy when he first takes a dose or goes up on the dose. Then a day or so later it goes away.
My daughter has been on stratterra since October. I can't recall if we noticed sleepiness when she first began because we were just too darn excited about the positives we were seeing! She takes 20mg once a day. She does need a nap sometimes which she never did before but I generally don't see sleepiness. We still have to give her clonidine at night to go to bed.
Remember that it takes several weeks for it to really kick in. Hopefully this will pass as it gets into his system.