There are positions were an employer is not required to emloy someone on certain medication, even if prescribed for a legitimate condition and even if a doctor says its ok, if it is not unreasonable that the medication or drugs could pose safety risks. Examples include certain driving jobs, piloting, operating heavy equipment, etc. The law simply does not make the employer undertake additional risk of liability, due to possible personal injury or property damage.Trying to cheat the drug test is extremely unwise: when that comes out later (e.g. when the employer becomes aware of the drug use), you could be fired "for cause" (no unemployment) and in some contexts face liability (e.g. besued), too.There are many jobs where amphetamine usage isnot an issue: it would better to focus on those.