Adderall® produces increased striatal dopamine release and a prolonged time course compared to amphetamine isomers

Rationale: Adderall® is currently used for the treatment of Attention-Deficit Hyperactivity Disorder (ADHD) and is composed of a novel mixture of approximately 24% l-amphetamine and 76% d-amphetamine salts. There are, however, no investigations of the pharmacological effects of this combination in vivo. Objectives: The technique of high-speed chronoamperometry using Nafion®-coated single carbon-fiber microelectrodes was used to study amphetamine-evoked dopamine (DA) release produced by Adderall®, d-amphetamine, or d,l-amphetamine in the striatum of anesthetized male Fischer 344 (F344) rats. The amphetamine solutions were locally applied from micropipettes by pressure ejection. Results: Local applications of Adderall® resulted in significantly greater DA release signal amplitudes with prolonged time course of dopamine release and re-uptake as compared to d-amphetamine and d,l-amphetamine. Conclusions: These data support the hypothesis that the combination of amphetamine enantiomers and salts in Adderall® has effects on DA release, which result in increased and prolonged DA release, compared to d- and d,l-amphetamine.