The term "narcotic," derived from the Greek word for stupor, originally referred to a variety of substances that dulled the senses and relieved pain. Today, the term is used in a number of ways. Some individuals define narcotics as those substances that bind at opiate receptors (cellular membrane proteins activated by substances like heroin or morphine) while others refer to any illicit substance as a narcotic. In a legal context, narcotic refers to opium, opium derivitives, and their semi-synthetic substitutes. Cocaine and coca leaves, which are also classified as "narcotics" in the Controlled Substances Act (CSA), neither bind opiate receptors nor produce morphine-like effects, and are discussed in the section on stimulants. For the purposes of this discussion, the term narcotic refers to drugs that produce morphine-like effects.

Narcotics are used therapeutically to treat pain, suppress cough, alleviate diarrhea, and induce anesthesia. Narcotics are administered in a variety of ways. Some are taken orally, transdermally (skin patches), or injected. They are also available in suppositories. As drugs of abuse, they are often smoked, sniffed, or injected. Drug effects depend heavily on the dose, route of administration, and previous exposure to the drug. Aside from their medical use, narcotics produce a general sense of well-being by reducing tension, anxiety, and aggression. These effects are helpful in a therapeutic setting but con tribute to their abuse.

Narcotic use is associated with a variety of unwanted effects including drowsiness, inability to concentrate, apathy, lessened physical activity, constriction of the pupils, dilation of the subcutaneous blood vessels causing flushing of the face and neck, constipation, nausea and vomiting, and most significantly, respiratory depression. As the dose is increased, the subjective, analgesic (pain relief), and toxic effect become more pronounced. Except in cases of acute intoxication, there is no loss of motor coordination or slurred speech as occurs with many depressants.

Among the hazards of illicit drug use is the ever-increasing risk of infection, disease, and overdose. While pharmaceutical products have a known concentration and purity, clandestinely produced street drugs have unknown compositions. Medical complications common among narcotic abusers arise primarily from adulterants found in street drugs and in the non-sterile practices of injecting. Skin, lung, and brain abscesses, endocarditis (inflammation (the fining of the heart), hepatitis, and AIDS are commonly found among narcotic abusers. Since there is no simple way to determine the purity of a drug that is sold on the street, the effects of illicit narcotic use are unpredictable and can be fatal. Physical signs of narcotic overdose include constricted (pinpoint) pupils, cold clammy skin, confusion, convulsions, severe drowsiness, and respiratory depression (slow or troubled breathing).

With repeated use of narcotics, tolerance and dependence develop. The development of tolerance is characterized by a shortened duration and a decreased intensity of analgesia, euphoria, and sedation, which creates the need to consume progressively larger doses to attain the desired effect. Tolerance does not develop uniformly for all actions of these drugs, giving rise to a number of toxic effects. Although tolerant users can consume doses far in excess of the dose they took, physical dependence refers to an alteration of normal body functions that necessitates the continued presence of a drug in order to prevent a withdrawal or abstinence syndrome. The intensity and character of the physical symptoms experienced during withdrawal are directly related to the particular drug of abuse, the total daily dose, the interval between doses, the duration of use, and the health and personality of the user. In general, shorter acting narcotics tend to produce shorter; more intense withdrawal symptoms, while longer acting narcotics produce a withdrawal syndrome that is protracted but tends to be less severe. Although unpleasant, withdrawal from narcotics is rarely life threatening.

The withdrawal symptoms associated with heroin/morphine addiction are usually experienced shortly before the time of the next scheduled dose. Early symptoms include watery eyes, runny nose, yawning, and sweating. Restlessness, irritability, loss of appetite, nausea, tremors, and drug craving appear as the syndrome progresses. Severe depression and vomiting are common. The heart rate and blood pressure are elevated. Chills alternating with flushing and excessive sweating are also characteristic symptoms. Pains in the bones and muscles of the back and extremities occur, as do muscle spasms. At any point during this process, a suitable narcotic can be administered that will dramatically reverse the withdrawal symptoms. Without intervention, the syndrome will run its course, and most of the overt physical symptoms will disappear within 7 to 10 days.

The psychological dependence associated with narcotic addiction is complex and protracted. Long after the physical need for the drug has passed, the addict may continue to think and talk about the use of drugs and feel strange or overwhelmed coping with daily activities without being under the influence of drugs. There is a high probability that relapse will occur after narcotic withdrawal when neither the physical environment nor the behavioral motivators that contributed to the abuse have been altered.

There are two major patterns of narcotic abuse or dependence seen in the United States. One involves individuals whose drug use was initiated within the context of medical treatment who escalate their dose by obtaining the drug through fraudulent prescriptions and "doctor shopping" or branching out to illicit drugs. The other; more common, pattern of abuse is initiated outside the therapeutic setting with experimental or recreational use of narcotics. The majority of individuals in this category may abuse narcotics sporadically for months or even years. Although they may not become addicts, the social, medical, and legal consequences of their behavior is very serious. Some experimental users will escalate their narcotic use and will eventually become dependent, both physically and psychologically. The younger an individual is when drug use is initiated, the more likely the drug use will progress to dependence and addiction.

Narcotics of Natural Origin

The poppy Papaver somniferum is the source for non-synthetic narcotics. It was grown in the Mediterranean region as early as 5000 B.C., and has since been cultivated in a number of countries throughout the world. The milky fluid that seeps from incisions in the unripe seedpod of this poppy has, since ancient times, been scraped by hand and air-dried to produce what is known as opium. A more modern method of harvesting is by the industrial poppy straw process of extracting alkaloids from the mature dried plant. The extract may be in liquid, solid, or powder form, although most poppy straw concentrate available commercially is a fine brownish powder. More than 500 tons of opium or its equivalent in poppy straw concentrate are legally imported into the United States annually for legitimate medical use.

Synthetic Narcotics

In contrast to the pharmaceutical products derived from opium, synthetic narcotics are produced entirely within the laboratory. The continuing search for products that retain the analgesic properties of morphine without the consequent dangers of tolerance and dependence has yet to yield a product that is not susceptible to abuse. A number of clandestinely produced drugs, as well as drugs that have accepted medical uses, fall within this category.