Does anyone know how to deal with the side effects of dexedrine?

What if you knew someone that was addicted to this drug and noticing some very alarming changes within them? If they confided in you that they are taking doses which would be considered 4-5 times the amount that is normally prescibed. What if they told you that they are having strange effects like: numbness, like their hands falling asleep permanetly; or feeling like they are kind of floating (not sure how to relate this one).

I think that this may be warning symptoms of overdose but unsure of this. So I was hoping that others here would know more about this drug and the effects.

Thanks all

Justy