Amphetamine (Adderall) mechanism of action is:

Correct answer: D. Increases dopamine, norepinephrine (and serotonin) release in the synaptic cleft → CNS stimulation

• A. Alpha-2 blockade would increase norepinephrine release — but this is not amphetamine's primary mechanism.
• B. Inhibiting dopamine reuptake only describes methylphenidate (Ritalin) more than amphetamine.
• C. Increasing GABA activity would cause sedation — opposite of amphetamine's stimulant effects.
• D. Correct. Amphetamine is a CNS stimulant that works by: (1) promoting RELEASE of dopamine, norepinephrine, and to a lesser extent serotonin from nerve terminals, (2) inhibiting reuptake of these monoamines, (3) inhibiting MAO (monoamine oxidase). The net effect is massive increase in synaptic monoamine concentrations, causing CNS stimulation, increased alertness, and appetite suppression. DENTAL: causes xerostomia, bruxism, 'meth mouth' pattern (though from abuse).