Codeine is a narcotic, and as a narcotic drug, this means that it is highly addictive. Therefore, use of this pain medication should only be with a prescription, and for the treatment of a valid medical condition that does warrant its use for relief from pain. It should not be used without a prescription. Also, never use this medicine for longer than prescribed, because it is not recommended. Codeine can slow one's breathing, or stop it completely in some cases, if it is taken in larger than the normal amounts. Don't take codeine if you are allergic or are sensitive to it. It is also not recommended to use if one has an uncontrolled form of breathing problem, a bowel obstruction issue that is called paralytic ileus, or if you suffer regular attacks of asthma or hyperventilation.