Amphetamine- a synthetic, addictive, mood-altering drug, used illegally as a stimulant. 

Amphetamine is medically used in the treatment of Attention Deficit Hyperactivity Disorder (ADHD), narcolepsy and obesity.

Ice is a slang name for crystal methamphetamine – a stimulant drug that is swallowed, smoked or injected. Speed and ice are chemically the same drug but instead of a powder, ice is produced in a crystal form that is stronger than speed.