Brief Answer:
He can take Vyvanse with Imitrex under physician's supervision

Detailed Answer:
Hello

Thanks for the query

Vyvanse contains amphetamine and is use in children for attention deficit hyperkinetic disorder.
Imitrex contains sumatriptan and is used in migraine.

Although the mechanism of action of both these medications are different;both of these increases serotonin(a chemical) level in blood causing flushing,anxiety,perspiration and low blood pressure.

Use of imitrex is not contraindicated with vyvanse but it should be used under physician supervision.
So you can give it to your son if advised by your physician.

I shall be glad to answer if you have any more query.
Regards

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