What It Is:
Amphetamines are highly addictive stimulants that accelerate functions in the brain and body. They come in pills or tablets. Prescription diet pills also fall into this category of drugs.
Sometimes Called: speed, uppers, dexies, bennies
How It’s Used: Amphetamines are swallowed, inhaled, snorted, or injected.
What It Does:
No matter how a person takes amphetamines, these drugs hit with a fast high, making the user feel powerful, alert, and energized.
These “uppers” pump up heart rate, breathing, and blood pressure, suppress appetites, and can also cause sweating, shaking, headaches, sleeplessness, and blurred vision.
Prolonged use may cause hallucinations and intense paranoia.
Users who stop taking amphetamines experience withdrawal symptoms, such as aggression, anger, and strong cravings for the drugs.
source: http://kidshealth.org/parent/positive/talk/drugs_amphetamines.html