morphine
- Morphine
- Tramadol
- Piritramid
- Codeine
- Fentanyl
- Buprenorphine
- Pentazocin
Opioids can be supplied in a variety of ways. As tablets (peroral), intravenously (i.e. injected into a vein), as suppositories (rectal), as patches (transdermal) or as drops. Opioids/morphine have great potential for dependence.
This potential is stronger or weaker depending on the type of intake and the substance being administered. For example, the intravenous supply of heroin (a derivative of morphine) has the greatest potential for dependence, since heorine floods the brain extremely quickly and thus provides the “desired” state of intoxication within a very short time after ingestion. Withdrawal symptoms include sweating, pain, diarrhea, vomiting and circulatory failure.
Tolerance development occurs when an opioid is taken over a longer period of time. This weakens many of the effects, and habituation develops. Above all, it is the analgesic (i.e. the only desired effect) that diminishes.
The least affected by the development of tolerance are constipation (constipation) and pupil constriction (miosis), so they still occur without restriction even after prolonged intake of opioids. An overdose of opioids is usually accompanied by a typical triad of symptoms: Therapeutically, an opioid antagonist must be administered as soon as possible in order to counteract the effect of the poison as best as possible. Naloxone is usually used as such an antidote.
It is important to note that naloxone has a relatively short half-life of one hour, whereas most opioids act much longer in the body, so that naloxone must be re-injected at regular intervals.
- Miosis (narrow pupils)
- Breathing Depression
- Coma
The different opioids have very different analgesic effects. Morphine has been assigned potency 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 and is therefore 1000 times more pain-relieving than morphine (which means that it could be administered at 1000 times lower doses than morphine to achieve the same analgesic effect). In order to mention some further strengths of action, a small list of pain relief in descending order of magnitude follows: Sufentanil < Fentanyl < Buprenorphine < Morphine < Piritramid < Pentazocin < Codeine < Tramadol < Tilidine.
Administered as a tablet, morphine is well absorbed (absorbed into the blood from the gastrointestinal tract), but it is subject to a distinct first-pass mechanism (since the blood into which morphine is absorbed from the gastrointestinal tract first flows through the liver, where a large proportion of the morphine is already metabolized, relatively little of the active ingredient arrives in the organism, so the bioavailability of morphine is low). However, this is already taken into account when administering the drug 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 about 2-4 hours.
