What are Opioids?
Opioids are a type of medication used for pain relief. They are derived from a common opium poppy plant, Papaver somniferum. The active substance - opium, can be mainly found in the plant's milky sap and the seeds. Its analgesic properties have been known for centuries with the earliest mentions up to 3 400 years BC. Present-day opioids contain the same active substance or are designed in a lab to have a similar structure. Thanks to that they can stop the transmission of pain signals between the brain and spinal cord, essentially providing pain relief. Prescription opioids are usually recommended to patients following surgery or injury, or to alleviate chronic pain in terminally ill patients. However, their use is associated with risks such as misuse, abuse, addiction, and overdose deaths [15], [16], [17], [18].
Types of Opioids
Opioid medicine can be categorized by their origin into natural, synthetic, and endogenous opioids.
Natural opioids are derived from the poppy plant and include drugs like morphine, codeine or thebaine [2].
Synthetic opioids mimic the action of natural opium but are chemically designed in a lab, usually the prescription opioids including oxycodone (OxyContin, Percocet), oxymorphone, hydrocodone (Vicodin), tramadol (Ultram, Ultram ER), but also street drugs like fentanyl or heroin.
Endogenous opioids on the other hand are naturally produced in the body. They are feel-good substances, usually protein, which play a role in pain pathways and reward systems in the brain, for instance endorphins or enkephalins [3].
How do opioids work?
Opioid drugs are psychoactive substances, which means they affect our brain and mental processes. They interject the pain signals by targeting a group of different opioid receptors located in the areas of the brain, involved in feeling pain and pleasure. When opioids bind to the receptors, they inhibit the release of neurotransmitters. This stops the transmission of pain signals between neurons, blocking any pain feelings. At the same time, opioids activate the reward circuit in the brain, which releases earlier mentioned endogenous opioids, the feel-good chemicals. Combined, opioids provide the "high" feelings of euphoria, as well as pain relief.
What are the side effects of opioids?
In general, opioid pain relievers contain substances which relax the body and slow down the communication between our brain and the rest of the body. Unfortunately this results in more than just pain relief and euphoria. Even when used exactly as instructed, prescription opioids have been reported to cause a variety of side effects, ranging from mild to more severe ones. The most common ones include:
- impaired decision making skills
- slowed reaction time
- problems with focus
- drowsiness
- confusion
- nausea/vomiting
- constipation
- sedation
- respiratory depression [4]
Respiratory depression is a more severe side effect of opioid medicines and is the reason why it's so easy to overdose. As mentioned before, opioids slow down the messages between your brain and the rest of the body, which also includes our breathing cues. When our breathing slows down, not enough oxygen is delivered to the brain and spinal cord, which means neurons don't have the needed conditions to work properly, which in turn can cause cell death. Additionally, your heart rate slows and your blood pressure decreases, which when all combined can lead to permanent brain damage and even death. [5]
Additionally, opioids can dangerously interact with other drugs and substances. For example, combining morphine or hydrocodone with alcohol can be lethal.
Can the brain build tolerance to opioids?
Yes, it can. The biggest argument against prescribed opioids is the fact that their long-term use builds tolerance against its beneficial effects. Even when using prescribed opioids, over time our brain adapts to their action. The opioid receptors get desensitized, meaning a bigger concentration of opioids is needed to get the same result[6]. Therefore, our body needs higher and higher doses of opioid medication to alleviate the same levels of pain. After a long time of opioid use neurons are adapted to work normally ONLY in the presence of opioids. Reports state that this physical dependence causes withdrawal symptoms in even up to 85% of patients who stop taking their regular dose of opioids [7]. This only further pushes them further to substance abuse.
What are opioid withdrawal symptoms?
Once the prescription opioid use stops, the onset and duration of these symptoms might differ based on factors like the type of opioid ingested, the dose taken, the tolerance of the individual and their general health. Some of the withdrawal symptoms include:
- muscle aches
- yawning very often
- anxiety
- excessive sweating
- inability to sleep
- severe pain in the abdomen
- nausea and vomiting
- rapid heart rate and high blood pressure
Additionally, if a pregnant mother was using opioids, after birth the infant might suffer its own withdrawal symptoms called the neonatal abstinence syndrome. These include:
- poor feeding
- dehydration
- digestive issues
- vomiting
- seizures [8]
What is the Opioid Use Disorder?
Opioid Use Disorder (OUD) is a complex chronic illness characterized by compulsive drug misuse, negatively affects a patient's general wellbeing. It encompasses a spectrum of behaviors, from misuse to addiction, and can have devastating effects on individuals, families, and even communities. Some first signs of the disorder are increasingly heavy, frequent or risky use or drug cravings. The opioid use disorder has been described as a a public health crisis in the United States with over 800 thousand Americans dying from opioid overdose between 1999 and 2020 [9].
It is important to note that taking even prescription opioids exactly as recommended by your healthcare provider is enough to cause opioid dependence or opioid addiction. Once your brain builds tolerance, you might not even notice that you start taking your prescription drugs more frequently to ease the withdrawals like a simple headache, or to restore the euphoric feelings it gives you. This constant need for a higher dose might lead patients to seek solutions in illicit drugs, such as heroin. In fact, even 86% of users of illegal drug heroin have started their addiction with taking prescribed opioids [10].
What is the cause of the opioid crisis?
Opioids became increasingly popular in the mid 1990s when Purdue Pharma came out with OxyContin - new synthetic opioids, which Purdue claimed were supposedly less addictive than standard opioid medicine, despite having no scientific proof of that. Their brilliant marketing helped popularize the drug which became readily prescribed to all patients, who slowly, but surely were developing opioid dependence or addiction. The pharmaceutical companies' aggressive strategies, corruption of doctors and lack of regulation led to the opioid medications being overprescribed in higher and higher doses getting more patients "hooked". At the same time, this increase in popularity seeped into the street market, where these prescription opioid drugs were illegally prescribed for recreational use. Since then, the opioid epidemic has only continued to spread further, with over 16 mln people worldwide and 2.1 mln people in the United States currently suffering with opioid use disorder [11].
How to prevent the spread of the opioid epidemic?
To successfully tackle this increasing problem we need cooperation from the medical community, emergency departments, public health, as well as policy makers and social workers to enforce harm reduction. Firstly, we need to educate ourselves and our communities about this problem, share the resources to those in need, as well as decrease the harmful stigma around this subject by bringing more awareness to it. Some of the further steps include:
- monitoring current trends
- improving drug monitoring programs
- increasing public awareness
- partnering with public safety officials, as well as the law enforcement
- educating providers and health care system to increase patient safety
- expansion of addiction treatment services. [1]
What are treatment options for opioid addiction?
As mentioned before, opioid use disorder is a very complex condition, therefore successful treatment must be suited individually. Not everything will work for everyone. Usually the first step is detoxification, a process in which the patient quits taking drugs and has to suffer through the withdrawal symptoms. This can be done rapidly, as in quitting "cold turkey" without help of any drugs, or by using a synthetic opioid agonist like methadone and buprenorphine to help ease the severe pain of withdrawals. Depending on the route chosen the process can last for days or even months and is far more uncomfortable than withdrawal from other drugs, like alcohol. Unfortunately, these negative sides of detoxification contribute to a relatively high rate of patients relapsing, with the numbers ranging from 24.25% to 77% of people returning to their opioid addiction within 6 - 24 months after detoxification. [12].
In case of opioid overdoses, naloxone, also known as Narcan, is used. It is an over-the-counter drug in a nose-spray, which when inhaled binds to opioid receptors and blocks the opioid effects. It reverses depressed breathing, decreased heart rate, or extreme drowsiness and therefore prevents overdose deaths. Naloxone should be used immediately in a case of a suspected overdose. However it is important to remember that in such case, the patient still needs to receive medical care as soon as possible
What are the new guidelines for medical use of opioids?
The Centers for Disease Control and Prevention (CDC) developed guidelines to slow down the opioid epidemic. The steps include use of non-opioid alternatives for most cases of chronic pain, using the lowest effective dose when prescribing opioids, and exercising caution/monitoring patients who are treated with opioids. The CDC also suggests using prescription drug monitoring programs and urine drug testing when prescribing opioids [13].
What are some opioid alternatives?
If you're worried about the side effects of opioid medication or concerned about developing opioid dependence consider these alternatives, which will help you with pain, but are not addictive. Always in case of any questions or concerns contact your healthcare provider.
- ibuprofen
- acetaminophen
- aspirin
- local anaesthetics
- muscle relaxers
- cannabidiol
- corticosteroids [14].
Conclusion
Opioids have played a vital role in alleviating powerful pain and suffering for millions of people worldwide. However, their widespread overprescription and lack of education on their negative health effects has led to a devastating epidemic of drug misuse, substance use disorder and opioid overdose deaths. By understanding the mechanisms of opioids, their medical use, and the risks associated with taking them, we can make more educated decisions, which will benefit our general health and wellbeing.