When an individual uses prescription drugs irresponsibly or in contravention to the orders of a doctor or pharmacist but not to use drugs recreationally. For example, taking an extra sleeping pill or offering a prescription drugA name for a wide variety of chemical substances capable of altering the function of your mind and body in significant ways. These can include over the counter prescriptions, alcohol, and controlled substances. Most drugs are either physically and/or psychologically habit-forming. More to a friend.