Generality
The term "narcotics" generally refers to a set of drugs that - in addition to the analgesic effect - are also able to induce narcosis in the patient.
In the past, the term "narcotics" was used to indicate all the active ingredients belonging to the class of opioid analgesics; however, currently this term is considered rather obsolete and somewhat ambiguous, since, often, the word "narcotics" is used improperly also to indicate other drugs or substances that act on the central nervous system without inducing narcosis, such as, for example, sympathomimetics, hallucinogens and psychotomimetics.
However, in these cases, opioid drugs that induce narcosis are preferentially referred to as "narcotic analgesics".
Finally, sometimes, deep sleep induced by narcotics is identified - in surgery - with general anesthesia. For this reason, it may happen that the term "narcotics" is also used to indicate general anesthetic drugs.
Narcotic analgesics
As stated, narcotic analgesics are identifiable with opioid drugs used in the treatment of pain and capable of inducing narcosis.
The active ingredients belonging to this class of drugs can be divided according to their origin; therefore, we can distinguish:
- Narcotic analgesics (or opioids) of natural origin, such as morphine and codeine;
- Semisynthetic narcotic (or opioid) analgesics, such as buprenorphine and heroin (the latter, however, is not a drug, but a drug of abuse);
- Synthetic narcotic (or opioid) analgesics, such as methadone, meperidine (also known as pethidine), tramadol and fentanyl (or fentanyl, if you prefer).
Therapeutic indications
As mentioned, all narcotic analgesics (except illegal ones, as drugs of abuse, such as heroin) find use in the treatment of moderate to severe pain.
More specifically, the use of this type of drugs is particularly useful in the case of neoplastic pain, chronic pain associated with different types of diseases and perioperative pain. Not surprisingly, narcotic analgesics are part of the large group of medicines used in pain therapy.
Codeine, on the other hand, in addition to being exploited for its analgesic activity, is also used in therapy - at the appropriate dosages - as a cough medicine, since it is also endowed with interesting antitussive properties.
Action mechanism
Narcotic analgesics - hence opioid drugs, or opioid analgesics, if you prefer - carry out their action by interacting with opioid receptors present in our body (endogenous opioid receptors).
There are four different types of opioid receptors: μ receptors (otherwise known as MOPs); the δ receptors (also known as DOP); the κ receptors (otherwise known as KOP) and the orphan receptors (also known as NOP).
These receptors are located and distributed along the pain pathways of our body and their activation is able to induce a marked analgesic effect.
Therefore, narcotic analgesics exert their pain-relieving action through the stimulation and activation of the above-mentioned opioid receptors.
Side effects
Narcotic analgesics are very powerful painkillers, but they have side effects that should not be underestimated. This is why their prescription is strictly regulated by law.
The type of side effects and the intensity with which they occur can vary greatly from individual to individual, also depending on the dose of drug administered. In fact, many side effects caused by narcotic analgesics are dose-dependent (such as, for example, respiratory depression).
However, among the main adverse effects that can occur following the intake of narcotic analgesics, we recall:
- Drowsiness and sedation;
- Narcosis (in fact, narcosis is considered a secondary effect, since these active ingredients are used for their analgesic action and not to induce a state of deep sleep);
- Nausea and vomit;
- Miosi;
- Euphoria and excitement;
- Confusional states;
- Respiratory depression.
Finally, narcotic analgesics can cause addiction, tolerance and dependence, both physical and psychic.
Dependence on narcotic analgesics constitutes a real drug addiction, which must be properly treated, since its implications can also be tragic.
However, it should be remembered that - if used at the right therapeutic doses and under the strict supervision of the doctor - narcotic analgesics are unlikely to give rise to phenomena of dependence.
