Hate to bump an old thread, but...
I've been experiencing paradoxical effects from dextroamphetamine as well lately. Ill take my ADHD meds and all of a sudden I get really tired and unmotivated. What the most amazing feet about this is, a couple hours ago, I took 90MG's of D-Amp (which is a considerably high dose) started watching some TV while I waited for it to kick in and somehow manage to FALL ASLEEP!!! Can you believe that?! 90MG's of dextroamphetamine and fell asleep!
Interestingly enough, though - I only experience this with medications that only contain dextroamphetamine. Adderall for instance is only 75% d-amp and 25% L- amp. Levoamphetamine has much more affinity for the norepinephrine receptors which is, I'm assuming, why I never get tired from Adderall and always feel speedy really speed when I've taken adderall