Will benedryl kill the effects of adderall (dextroamphetamine and racemic amphetamine)?

Benadryl (diphenhydramine): Depends on dose & what effects u r referring to, but usually no.

Possibly: These two medications can have opposite effects. So the Benadryl (diphenhydramine) can end up cancelling the beneficial effects of the adderall. Speak with your prescribing doctor before you mix medicines.

Not necessarily: Adderall (dextroamphetamine and racemic amphetamine) is a stimulant with brain underarousal. Benedryl is a potentially sedating medication. therefore, benedryl may interfere with the action of adderall (dextroamphetamine and racemic amphetamine).