Thank you for your question and welcome to Health Central's ADHD Community.
I am not a medical professional and would not be able to give you medical advice. This is a question you should direct to your doctor or pharmacist. He or she would better know the possible interactions and whether these medications can be taken at the same time or if they should be taken at different times of the day.
You don't mention how old your son is, but many teens, both with and without ADHD, sleep through most of the morning when given the chance. This may be simply a teen behavior rather than an ADHD behavior.
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