Interesting Facts About Opioids And When To Use Them
Opioids are mostly used as pain relievers, but they can also alleviate other symptoms. They are usually prescribed on special receptors.
Since time immemorial, we have been looking for effective pain relievers to alleviate suffering and improve the quality of life. Opioids are widely used to reduce severe pain and to achieve this goal.
The consumption of these drugs has increased sharply in recent years: per capita consumption in Germany is now almost as high as in the USA. Abuse is a huge problem because opioids are addicting. Often prescribed to keep patients happy, they can make them dependent or end up in the wrong hands.
Learn more about opioids and how they are used today.
Opioids: classification
Opioids can be classified differently depending on their action profile:
- Pure agonists
- Mixed agonist-antagonists
- Partial agonists
- Pure antagonists
Opioids: pure agonists
Opioids that have a purely agonistic effect bind directly to μ-receptors and have an exclusively activating effect. They therefore calm pain and trigger euphoria. But they also lead to respiratory depression, constipation, nausea, nausea and urinary retention.
The fact that so many effects are triggered by activating the receptors is a major disadvantage in the treatment of pain. Because the desired pain relief is associated with numerous unpleasant side effects.
The prototype for an opioid with a purely agonistic effect is morphine. The higher the dose, the better the pain relief. But this also increases various side effects.
Heroin also has a strong analgesic effect, but since it is a highly addictive substance, it is not allowed as a pain reliever in most countries.
Pure agonists are opioid drugs that have very strong intrinsic activity. They are often used to relieve pain in the following cases:
- after operations
- severe chronic pain that cannot be relieved by other pain relievers
- for the concomitant treatment of cancer
- for severe temporary pain
- and heart attack pain
Opioids: Mixed agonist-antagonists
Opioids with a mixed agonistic-antagonistic effect are not specific, which means that they can exert a partially agonistic or also antagonistic activity. They show weak intrinsic activity at μ-receptors, but high intrinsic activity at κ-receptors and δ-receptors. By activating these receptors at the same time, they have a strong analgesic effect.
Although these drugs do not cause respiratory depression, they also have various unpleasant side effects, such as hallucinations, nervousness and nausea.
They are also addictive, but drug addiction does not overlap with purely agonistic drugs that bind to μ-receptors. This group includes, for example, the drug pentazocine, a centrally acting analgesic which, however, is no longer approved in Germany.
- Mixed agonist-antagonists are used in particular to relieve moderate to intense pain.
Opioids: partial agonists
Partial agonists have a lower intrinsic activity than pure agonists. In combination with pure agonists, this medicinal product can therefore also have an antagonistic effect.
The only pharmacologically used drug in this group is buprenorphine, which has an analgesic effect 20-30 times stronger than morphine. It interacts with different receptors. In addition, it has a particularly long duration of action, although it also takes longer to become dependent on it.
Buprenorphine is often used in the following cases:
- Treating moderate or severe pain
- Analgesic before or after operations
- if you are addicted to other opioids such as heroin
Opioids: Pure antagonists
Pure antagonists act with different affinities on all receptor types, but have no intrinsic activity. The affinity is higher for μ receptors than for κ and δ receptors.
This group includes, for example, the drug naloxone, which is usually administered in medical emergencies to treat an overdose of opioids, which are life-threatening. It is therefore an antidote that can be used in opiate intoxication.
However, naloxone is also used after anesthesia to reverse the effects of opioid drugs that are used during surgery. This medicine is also used in newborn babies to reduce the effects of opioids that the pregnant mother receives before the baby is born.
