The drugs are normally prescribed to treat attention deficit hyperactivity disorder (ADHD), but healthy students use them to get a leg up in school, by improving focus, concentration and memory.
Adrenaline, or epinephrine, is a hormone that dilates an individual's air passages and increases his heart rate when he is faced with a stressful situation. The hormone is secreted from the adrenal glands to help ensure survival under dangerous situations.
The liver plays a central role in transforming and clearing chemicals and is susceptible to the toxicity from these agents. Certain medicinal agents, when taken in overdoses and sometimes even when introduced within therapeutic ranges, may injure the organ.