//graizoah.com/afu.php?zoneid=3337959 X. NARCOTIC ANALGESICS - methadone-anonymous


Methadone HCL Tablet, Soluble. ... This medication is used to treat addiction to opioids (such as heroin) as part of an approved treatment program. Methadone belongs to a class of drugs known as opioid (narcotic) analgesics.



Thursday, December 19, 2019



KNOWN GENERALLY AS NARCOTICS (a term derived from narcotics, a Greek word that means numbness), are substances related to opiates, which are mainly used to combat pain. We will not speak here of the group of non-narcotic analgesics, such as aspirin since these owe their effects on non-neural mechanisms involved in inflammatory processes.
Portrait Photo of Woman in Red Top Posing with Her Hand on Her Cheek

The group of opiates, whose prototype is morphine, has particular interest from the discovery of morphine-like substances within the brain. They are called enkephalin and endorphins.

(The history of opium and its derivatives is interesting, and will be seen in more detail in Chapter XXVI).

The word opium is derived from juice in Greek since the drug is obtained from the juice extracted from the poppy bulbs (Papaver somniferum). Arab doctors knew its effects well and were probably the ones who introduced opium into the East, where it was basically used against dysentery (acute diarrhea). By the 17th century, poppy juice was relatively popular in Europe and by the 18th century, it was smoked in both the East and the old continent.

Opium contains more than 20 alkaloids. In 1803, the German chemist Sertürner isolated one of them: morphine (named after Morpheus, the Greek god of sleep), and from that moment several of them were isolated, such as codeine and papaverine. With the invention of the hypodermic needle, and the possibility of obtaining more intense and rapid effects, the era of massive opioid abuse began, particularly during wars in which the wounded were given morphine to fight relatively indiscriminately pain, thus producing addicted subjects. From the War of Secession in the United States of America to the Vietnam War, this problem has run to date. (We will deal with the problem of this addiction in Part Five of this work).

Compounds capable of antagonizing the effects of opiates were synthesized starting in 1915. It was necessary to have such antidotes to combat respiratory depression caused by morphine or heroin overdose, which is the most frequent cause of death due to opioid poisoning. But as we will see later, the use of these antagonists can be dangerous in addicted subjects, since their administration induces the abrupt appearance of withdrawal or suppression syndrome (which will be described later).

The chemical synthesis of morphine-derived substances produced new drugs with analgesic effects on the one hand, antagonist on the other, and also mixtures of both. The existence of substances with such varied effects suggested the existence, at the nervous system level, of different types of opioid receptors. In 1973, three different groups of researchers reported the discovery of opiate recognition sites (receptors) in the mammalian nervous system. Two years later, John Hughes and Hans Kosterlitz, in England, report the isolation, from pig brain extracts, of two peptide-type substances (peptides, formed by amino acids, are the molecules that integrate proteins) that showed morphine-like effects that could be reversed with naloxone, the most potent opioid antagonist known until that date (in pharmacology, the availability of pure and specific antagonists is essential for the study of receptors). These peptides were called encephalin. The same year, the Avram Goldstein group at Stanford University described a substance, also of the polypeptide type, in the pituitary gland (pituitary gland) of cattle with opioid-like activity, which they called b-endorphin. Currently, three families of opioid peptides are known: enkephalins, endorphins, and dynorphins. Each of these families is derived from a different precursor and has a different anatomical distribution. These precursors are known as proenkephalin, proopiomelanocortin (POMC) and prodynorphin, respectively. Each of them gives rise to several active substances. Depending on where in the peptide chain a cut is made (which is made by specific peptidases that recognize the particular amino acid sequence), polypeptides with different effects are obtained.

In an ingenious mechanism that nature has created to exert a finer control of biological functions from a single substance, by causing it to be formed, in turn, by other substances also active (such as a fruit that was the union of all fruits and containing all the flavors, colors, textures and smells of all fruits.The tree that produced this original fruit would have the ability to produce any fruit, because it would have everything necessary for it and know how to use it [ enzi

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