Amphetamine is understood to inhibit monoamine oxidase, whereas the power of amphetamine and its metabolites to inhibit a variety of P450 isozymes together with other enzymes hasn't been adequately elucidated. In vitro experiments with human microsomes show small inhibition of CYP2D6 by amphetamine and minimal inhibition of CYP1A2, 2D6, and 3A4 by