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 subunits 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 derivatives, 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