I personally would not combine the adderall and tyrosine. Not at the same time of the day anyway. Would definantly do the tyrosine alone, or the adderall for one dose and then later the tyrosine.
With the amount of l-tyrosine used is in the high range, (what you would need it to be at for treatment of ADHD) some people become energized, more focused, but some people get side effects from too much tyrosine like headaches or anxiousness. I wouldnt be suprised if that happened to someone while they were on a stim med & took l-tyrosine in addition.
If you must stay on the meds or are just wanting to taper off slowly and let the tyrosine start working I'd start by taking the meds in the morning, l-tyrosine after school, then a little at bedtime. Only give l-tyrosine to those who dont have the side effect of being VERY alert, these people might have trouble sleeping with a after dinner dose.
L-Tyrosine should be taken on an empty stomach at least an hour after dinner (preferably 2 hours)
When combining tyrosine in theraputic levels with adderall i would definantly want to be in contact with a nutritionalist or a good pharmacist whos knowledgeable of supplements. Don't give adderall and the l-tyrosine in the same dose.
There are combination products with low enough amounts of a variety of ingrediants that are better to take when you are also going to continue medications.