Well, the good news is it's not over-sedating for your difficult child. Depending on his body weight it may be slightly on the low side as a dose, or it may be just about right. With oral administration, peak serum levels happen in about two hours, with effect lasting six to twelve hours. Even though the medication would have started to wear off by bedtime there would still be some in his system (its half life is approximately ten to twenty hours, so about half would still be there by 11 pm).
Sunday nights can be really bad for any kids with anxiety issues as they start thinking about the week. Another trial, maybe a couple of hours before he usually gets ramped up, might show you some difference in his behavior. I'm glad he's not having major side effects with it!
