Strong-acting painkillers are grouped under the term opioids. They can lead to dependence if used in excess.
What are opioids?
Strong-acting painkillers are summarized under the term opioids. They can lead to dependence if used in excess. Opioids that are used as pain relievers are also called opioid analgesics. These agents exert a strong analgesic effect at the opioid receptors. Morphine is one of the best-known opioids. It has been used in the treatment of pain since the 19th century. Morphine is obtained from the opium poppy. Nowadays, synthetic and semi-synthetic opioids are also used. A distinction is made between therapeutically active and abused opioids. While therapeutic opioids are used in medicine to treat pain, misused opioids are used as intoxicants. Therapeutically supplied opioids are mostly derivatives of natural alkaloids. These may be subject to chemical modification and act as agonists at subtypes of opiate receptors. Well-known opioid representatives include tramadol, tilidine, oxycodone, fentanyl, alfentanil, meptazinol, sufentanil, pethidine, and diamorphine, which is also known as heroin. Like all other opioid analgesics, most of them fall under the Narcotics Act. Opium serves as the basic substance of opioid analgesics. This is the milky sap of the plant species opium poppy (Papaver somniferum), which contains various alkaloid species. They serve phenatrenes such as morphine, thebaine and codeine, and benzylisoquinolines such as noscapine, narceine and papaverine.
Pharmacological action
Opioids exert their effects directly on the central nervous system (CNS). In this process, the switching sites of the nerve cells are specifically blocked, which stops the transmission of pain signals. The analgesic effects of opioid analgesics result from µ-receptors, which are subtypes of opioid receptors. If a person suffers from physical or psychological stress, endogenous substances such as enkephalins and endorphins are released by the brain. These have the property of binding to the opioid receptors, which switches off the perception of pain for a short time. For this reason, victims of accidents, for example, often cannot perceive their injury pain at first. It is only as the pain progresses that it can be felt. Through this reaction, the body suppresses paralyzing pain reactions so that the person remains capable of acting. Opioids also act on these receptors. They suppress pain, reduce anxiety, inhibit breathing, block the coughing center, and weaken the ability to concentrate. There is also a constriction of the pupils, a decrease in urine output, stiffening of skeletal muscles, dilatation of blood vessels, and release of the hormone histamine. Since the bowels also empty more slowly, this leads to constipation. Some of these effects are considered undesirable, which is why they are classified as side effects.
Medical use and application
Opioids are used for particularly severe pain. They represent an important component of medical pain management. The pain is usually cancer pain, colic pain, accident-related pain, or pain from surgical procedures. Another indication is pain in the musculoskeletal system, as in rheumatoid arthritis, osteoporosis (bone loss) or osteoarthritis. Opioids can be administered in different ways. They can be taken in tablet form, injected by syringe or administered as suppositories. Patches with a transdermal effect are also available. One notorious effect of opioids is their mood-altering properties. Thus, some people use opioid-containing substances to make themselves feel euphoric, which falls under substance abuse. Opioid analgesics may therefore only be prescribed on prescription and are subject to strict medical control. In principle, opioids are the most effective painkillers used in medicine. A distinction must be made between weak opioids such as tramadol and strong agents such as morphine and fentanyl.
Risks and side effects
Because of the high potential for dependence, some physicians and patients are highly skeptical of opioids. However, when used properly, they provide optimal pain management and are usually well tolerated. However, constipation forms a common side effect. In such cases, patients can stimulate their bowel activity with naturally acting remedies such as flaxseed or prunes. However, laxative medications can also provide help. Other undesirable side effects associated with opioid use are nausea and vomiting, but these subside after one to two weeks. Alternatively, it is possible to administer antiemetics to reduce nausea. It is not uncommon for patients to also suffer from dizziness and fatigue. These side effects are particularly apparent in the initial phase of opioid therapy and disappear soon after. Rather rare side effects include problems with urination, dry mouth, itching, and cardiovascular problems. These symptoms are difficult to treat. In the event of an overdose of opioid analgesics, there is a risk of the dreaded respiratory depression. In the worst case, this can even result in a life-threatening respiratory arrest. Another problem with opioids is their great potential for dependence. If dependence occurs, those affected experience physical withdrawal symptoms such as motor restlessness, goose bumps, acceleration of breathing, sneezing, strong lacrimation, cold sweat, increased blood pressure and pain. After a few weeks, withdrawal symptoms usually subside. Psychological dependence is also possible for a certain period of time. This occurs due to the euphoric effects of opioids. Affected individuals then exhibit the insatiable craving for opioid use. One of the best-known forms of opioid dependence is heroin addiction. However, if opioids are used exclusively for pain management, the risk of dependence is considered low when treated properly.
