Non-narcotic and narcotic analgesics: the mechanism of action and application

Analgesics are the means that weaken or relieve the sensation of pain while retaining consciousness and other types of sensitivity. Physiologically, pain occurs as a result of excitation of the so-called pain receptors, which are localized to the skin, mucous and serous membranes, and also in the thickness of various organs and systems. Pain receptors are excited by physical (mechanical, thermal, electrical, etc.) and chemical exogenous (acids, alkalis, heavy metal salts, phenol derivatives, etc.) and endogenous factors of protein nature (histamine, serotonin, bradykinin).

Thus, pain is the physiological mechanism of the subjective manifestation of imbalance in the body, therefore it is protective. But extremely strong and prolonged pain is pathological in nature, as it depletes the body, disrupts the function of vital organs and can even lead to death from shock. From this point of view, the group of analgesics is of great practical importance, and historically it is an essential achievement of mankind.

Reduce or stop the pain can be in different ways. The most effective and radical is to eliminate the cause, which, unfortunately, is not always possible, because it is not always possible to quickly determine it. Therefore, it is often necessary to temporarily dull the pain with the help of drugs from various pharmacological groups. For this purpose, narcotic, local anesthetic, anticholinergic, antispasmodic, anticonvulsant, astringent, enveloping agents can be used .

By the nature of the action on the central nervous system, origin and chemical nature, analgesics are divided into two groups: narcotic and non-narcotic.

Narcotic analgesics are opium and drugs that have a similar effect. They are characterized, first of all, by a kind of impact on the central nervous system. They have analgesic effect, especially in cases not associated with inflammatory processes (with significant injuries, malignant tumors). Narcotic analgesics for repeated administration cause patients psychological and physical dependence. Drugs in this group increase the threshold of pain sensitivity. Such analgesics doctors appoint to eliminate severe pain in the presence of burns, injuries, etc. Also, these drugs are prescribed for patients with inoperable malignant neoplasms. Narcotic analgesics facilitate the psychological state of the patient. These drugs can not be used for more than three to four days, otherwise there is an addiction, and people become addicts.

Narcotic analgesics (opium) contain more than 30 alkaloids and additional substances, which include carbohydrates, proteins, lipids, mucus, mineral salts, etc. Opium contains a lot of morphine (about 12%), narcotin (up to 10%), codeine (up to 3-5%) and papeverin (up to 1%).

Narcotic analgesics: the most popular drugs

Among the means of narcotic action, the most important are morphine hydrochloride, codeine phosphate, dry opium extract, ethylmorphine hydrochloride (dionine), simple opium tincture, promedol, omnopon, etc.

Non-narcotic analgesics are agents that exhibit analgesic, anti-inflammatory and antipyretic effects. Unlike narcotic drugs, they relieve or relieve the pain associated with inflammatory processes in joints, bone, muscle and other tissues (in neuralgia, articular and muscular blini, rheumatism, dental lesions, etc.). This indicates that the basis of analgesia is the anti-inflammatory effect. In addition, non-narcotic analgesics do not cause hypnotic effects and euphoria, they do not suppress the centers of respiration and cough.

The antipyretic effect of non-narcotic analgesics is of great practical importance. As is known, the body temperature in diseases is increased due to the action of pyrogenic substances (products of the hydrolysis of proteins, amino acids, nucleic acids, microbial toxins, etc.) into the interoceptors, which transmit excitation to the center of thermoregulation. The excited center of thermoregulation, changing the intensity of the processes of heat production and heat transfer, promotes the hyperthermia of the body, has an important protective character. However, in some cases, hyperthermia can reach a level that is dangerous for the life of the organism, and its protective character turns into a pathological one. In such cases it is advisable to use antipyretic agents.

Non-narcotic analgesics: classification

Given the chemical structure of the drugs, they are divided into several groups: salicylic acid derivatives (methyl salicylate, acetylsalicylic acid or aspirin), pyrazolone (analgin, butadione, phenazone), para-aminophenol (paracetamol), indoleacetic acid (indomethacin), propionic acid (naproxen, Ketoprofen), anthranilic acid (fluphenam and mefenamic acid), pyrrolizin carboxylic acid (ketorolac).

Recently began to allocate one more group of anesthetics - nonsteroidal analgesics. The most popular drugs in this group are piroxicam, diclofenac, indomethacin. The mechanism of their action is associated with the blocking of the synthesis of the enzyme - cyclooxygenase. This enzyme promotes the formation of prostaglandins - the main mediators of pain and inflammatory reactions. Also these drugs block the allocation of bradykinin, which is involved in the occurrence and spread of pain and inflammation.