are drugs that excite the nervous system. Most are made from the opium poppy, (Papaver Somniferum) which is found mainly in Asia. were the first drugs used as medicines. They can relieve physical and emotional pain, and for this reason, they made very good medicines. The problem with is that they are highly addictive, and they make people develop tolerance. There are many different , the most common being heroin. Heroin effects the body in many different ways. It is usually a white powder that looks similar to powdered sugar. It can ....