Why would a doctor prescribe my friend vyvanse (lisdexamfetamine) when he has heavily abused adderall ritalin and illegal amphetamines like cocaine and meth ?

????: It's hard to get into another providers head. Clearly, the patient would have to be closely monitored and the benefits must clearly outweigh the risks.

UNINFORMED: I would wonder if your "friend" has been honest about the medications that have been abused. Vyvanse (lisdexamfetamine) is a prodrug and is not active if snorted ot injected. Still it is an amphetamine. Your friend will eventually be caught as there are more and more externally systems that monitor for doctor shopping and drug abuse.

Unknown: Need to know the rest of the story first. If you have concerns your friend is still not sober, and is abusing his or her meds, please encourage your friend to seek help for the addiction. There is no choice in having the disease of addiction, but those with addiction do have the choice to accept help.

MEDICATION: Best to discuss medication with your Psychiatrist. If uncomfortable with your Dr. consult another for a second opinion. Have a physical exam by a Dr. to determine a physical illness.