Drug

Morphine

Synonyms

morphine

English: morphine

definition

Morphine belongs to the class of opioids. It is a strong pain reliever (analgesic). It requires a prescription and is subject to the Narcotics Act (BtMG).

history

Morphine was first introduced in 1804 by F. W. A. Sertuner from the Alkaloid opium extracted. However, it was still 34 years before the chemical structure was deciphered. Sertüner named the fabric after the Greek god of dreams and sleep Morpheus. This is how the name morphine came about. Later, however, the name morphine caught on and is still the common name today.

Opioids

There Morphine the prototype of one Opioids it makes sense to explain its properties and effects to the whole group. Opioids are a group of powerful analgesics. They are made by the body itself in the form of Endorphins, Enkephalins and Dynorphins and produced by the pharmaceutical industry as potent pain relievers. They work on three different types of receptors in the body, which among other things have an analgesic effect. Dem ?-Receptor (spoken: effort), the ?-Receptor (spoken: delta) and the ?-Receptor (spoken: kappa). Depending on whether they have the same activating effect on the receptors as the body's own (endogenously) produced Opioids, i.e. agonists or whether they work contrary to the endogenous opioids, i.e. are antagonists and thus inhibit the receptors, the opioids are divided into different groups. Here is the somewhat simplified scheme:

1. pure agonists: act agonistically on all three receptors, i.e. they activate these receptors. Depending on the substance, the strength of the effect on the various receptors differs. This group includes, among others

Morphine
Tramadol
Piritramide
Codeine
Fentanyl

2. partial agonists / antagonists: hardly have an activating effect on the? - receptor, but more or less activating on the other receptors. This subclass includes:

Buprenorphine
Pentazocine

pure antagonists counteract the opioids on all receptors. So they cancel out (if they are present in sufficiently large quantities and can bind to the receptors) their effect. The most important representative of this group is naloxone. This substance is used in a poisoning with opioids (Opioid intoxication) is used as an antidote (antidote) and can thus have a life-saving effect.

Ingestion

Opioids can be administered in a variety of ways. As a tablet (perorally), intravenous (i.e. injected into a vein), as a suppository (rectal), as a plaster (transdermal) or as drops.

Dependence and development of tolerance

Opioids / morphine have great potential for dependence. This potential is stronger or weaker depending on the type of ingestion and which substance is administered. The intravenous supply of, for example, has the greatest potential for dependence heroin (Derived from morphine), since Heorin is extremely fast in the brain floods in and thus gives the "desired" state of intoxication within a very short time after ingestion.
Withdrawal symptoms include sweating, pain, diarrhea (diarrhea), Vomit and circulatory failure.
The development of tolerance occurs when an opioid is taken for a long time. As a result, many of the effects are weakened, and habituation develops. Above all, it is the analgesic (actually the only desired) effect that wears off. Constipation is the least affected by tolerance development (constipation) and the Constriction of the pupil (Miosis), so they still occur without restriction even after prolonged intake of opioids.

Poisoning (opioid intoxication)

An overdose of Opioids is usually accompanied by a typical triad of symptoms:

Miosis (narrow pupils)
Respiratory depression
coma

Therapeutic must be done as soon as possible Opioid antagonist given in order to neutralize the effect of the poison as best as possible. As such an antidote, naloxone is usually used. It is important to note that naloxone has a relatively short half-life of one hour, whereas most opioids work much longer in the body, so that naloxone must be injected at regular intervals.

Analgesic potency of opioids

The different opioids have very different levels of pain relieving effects. Morphine was assigned strength 1 so that the analgesic potency of the other opioids is measured against that of morphine.
Sufentanil has the strongest analgesic effect. It has a potency of 1000, making it 1000 times more pain reliever than morphine (which means that it could be administered in 1000 times less doses than morphine to achieve the same analgesic effect). In order to name a few other strengths, a small list should follow here - in descending pain relief:
Sufentanil <fentanyl <buprenorphine <morphine <piritramide <pentazocine <codeine <tramadol <tilidine.

Morphine - Pharmacology

Is administered as a tablet Morphine well absorbed (from the Gastrointestinal tract absorbed into the blood), but it is subject to a pronounced one first pass mechanism (because the blood in that Morphine the first was absorbed from the gastrointestinal tract liver flows through and a large part of the morphine is already metabolized here, relatively little active ingredient arrives in the organism, the bioavailability of Morphine is so low). However, this has already been taken into account when it is administered in tablet form, so that the dose in the tablet is so high that it still promises sufficient effect even after it has been broken down in the liver.
Morphine has a half-life of around 2-4 hours.