Is naltrexone an opioid?
Naltrexone is a prescription drug approved by the FDA for use in treating alcohol dependence and opioid use disorder. It is also used off-label with low dose compounds for low dose naltrexone therapy, or LDN treatment to treat chronic pain and a variety of other conditions.
Some people, even doctors, are confused over whether naltrexone is an opiate, an opioid, or an opioid blocker. They believe that naltrexone is an opioid.
Because of this mistaken belief, many doctors refuse to prescribe naltrexone, and many patients do not want to take it. Unfortunately, this confusion over how naltrexone works has likely led to under use of this safe and effective treatment medication.
Naltrexone does act on opioid receptors, but not as an opioid drug, but as a blocker. It blocks the opioid receptors, preventing endorphins, or natural endogenous opioids, and opioid drugs from binding.
Naltrexone is available as a long-acting injection (Vivitrol), a 50 mg tablet, and LDN (low dose naltrexone).
Why would doctors prescribe a naltrexone tablet or shot that blocks opioid receptors?
The obvious, common sense reason would be to treat people with an opioid addiction. As you can imagine, when opioid receptors are blocked, opioids are less effective, or completely ineffective. If a person on naltrexone treatment for opioid dependence tries to shoot up heroin, they are not going to get very high, or not high at all.
However, the benefits of naltrexone do not stop there. Naltrexone treatment also reduces cravings. We know that it reduces cravings for opioids, alcohol, food, and most likely stimulants, such as cocaine and methamphetamine.
By blocking both the effects of opioids and cravings for opioids, naltrexone, in conjunction with behavioral therapy, is an effective treatment for drug addiction involving opioid medication or opiate drugs. It is also highly effective for alcohol addiction treatment, and when combined with the medication, bupropion, effective for preventing binge-eating.
The mechanism for blocking cravings is believed to be related to a very specific opioid receptor. This receptor is known as the kappa opioid receptor.
Naltrexone is an effective blocker of the kappa receptor. Similarly, buprenorphine, another drug used to treat substance abuse with opioids and to prevent opioid withdrawal, also blocks the kappa receptor.
What is the kappa opioid receptor?
The kappa receptor is one of several opioid receptors that are either activated by opioid agonists, or blocked by an opioid antagonist, such as naltrexone.
When we think of people getting high with opioid drugs, or getting pain relief after surgery or from cancer, we think of the mu opioid receptor. The mu receptor is where analgesia (pain relief) and euphoria (pleasure) occur.
Why do we have these receptors in our central nervous systems? Do they serve a natural purpose?
Our bodies are able to produce endorphins, which are natural, endogenous opioids. If we are in pain, or if we are engaged in a rewarding activity, there is a release of endorphins.
For example, when I broke my ankle at the edge of a pool, I was able to swim to safety, and crawl far enough to get help. I knew that I was in severe pain, but, strangely, the pain did not bother me very much.
A flood of endorphins in my system protected me from being overwhelmed by the pain. While only a temporary effect, endorphins made it possible for me to get to safety.
The evolutionary benefits of endorphins are clear.
Endorphins have been saving lives for thousands of years, by giving temporary relief from severe pain to people who needed to get to safety quickly. Prehistoric humans relied on the effects of endorphins for survival.
Another purpose of endorphins is to program the reward centers of the brain. When a person engages in a positive, pleasurable activity, endorphins are released, enhancing the pleasure of the situation, and creating a new neural pathway to encourage the same behavior again in the future.
For example, sex causes a release of endorphins. The benefit is that the species is able to continue reproducing, because the brain’s reward center encourages repetition of the activity.
Eating delicious food also triggers endorphin release. In the past, this was a positive response, because tasty foods were typically safe and not poisonous, such as tasty meats, fruits, and vegetables.
In modern times, the endorphin reward center programming response can work against us with food. Refined foods that are not healthy taste delicious, because they have been designed to be delicious.
As a result, we tend to crave processed sweets and carbs that are harmful. Our reward center has been tricked to believe that these foods are good for us, so it is difficult to overcome the cravings that develop for unhealthy processed foods.
The modern world presents many temptations that are harmful to the reward centers of our brains.
The modern world has developed many unhealthy activities that bypass our higher, more developed brain, targeting the reward center with unhealthy pleasures. Powerful drugs, such as heroin, cocaine, and meth, or social media and video games, trick our primitive reward centers by triggering a flood of pleasure neurotransmitters.
As a result, we develop cravings and compulsions to engage in self-harming behavior. This is commonly described as addiction.
Some experts believe that addiction is always a result of trauma earlier in life. This may very well be a part of the problem, particularly with opioid addiction, where the drug covers up pain, including emotional pain.
The trauma explanation of addiction is a good psychological theory, but addiction is also related to physical changes in the brain.
How is the kappa opioid receptor possibly involved in relieving anxiety?
Getting back to the kappa receptor, there are some interesting things that happen when this receptor is blocked. Blocking the kappa opioid receptor results in a reduction of anxiety and depression.
Since naltrexone blocks the kappa receptor, we can say that naltrexone definitely has the potential to reduce anxiety. The anxiolytic effects of naltrexone would be attributed directly to its blocking action at the kappa opioid receptor.
However, clinically, naltrexone does not seem to be a useful anxiety treatment that works reliably for many people. If naltrexone worked very well for anxiety, it would probably be prescribed more often to people with anxiety disorders.
Yet, few, if any doctors prescribe naltrexone to help directly with anxiety. They may prescribe a beta blocker, such as propranolol, which reduces the physical manifestations of anxiety.
Or, they may prescribe a benzodiazepine or antidepressant to treat anxiety. These drugs have many side effects, and are not ideal long-term treatments.
While it would be great if the blocking action of naltrexone on the kappa opioid receptor provided reliable, significant anxiety release, it is probably not enough to help many people who suffer with anxiety. In fact, some people may complain that naltrexone causes anxiety.
Does naltrexone ever make anxiety worse?
Does naltrexone reduce anxiety or does it increase anxiety? While our understanding of how the drug works on the opiate receptors implies that it would help to reduce anxiety, for some patients, naltrexone may increase anxiety.
When a patient first starts taking naltrexone, they may experience various side effects. Often, these side effects will subside with continued use.
Side effects may include gastrointestinal discomfort, headaches, fatigue, and even anxiety. Starting with a lower dose at first may help to reduce the risk of having side effects.
For example, a doctor may prescribe naltrexone 25 mg at first, for several days. Then, when the patient has had some time to get used to the medication, the doctor will increase to the higher dose of 50 mg.
Opioid withdrawal symptoms may also occur if the patient is taking any opiate, opioid, or opioid-like drug at the time when they take their first dose of naltrexone. The herbal supplement, kratom, and the antidepressant, tianeptine, are examples of opioid-like drugs that could cause a precipitated withdrawal syndrome when combined with naltrexone.
Does low dose naltrexone help with anxiety or depression?
Low dose naltrexone, or LDN, is a specific unique treatment where the medication is dosed in the range of 0.5 mg to 6 mg, rather than the usual 50 mg to 100 mg dose range. The mechanism for how LDN treatment works is a bit different, compared to the standard full dosage treatment.
It is believed that LDN stimulates an increase in the production of endogenous endorphins. LDN may also help to stimulate the immune system to work more effectively, and reduce autoimmune activity.
There have been a wide range of claims of various health benefits from both low dose naltrexone, and ultra low dose naltrexone. While it remains to be seen if all of these claims are reliable and can be supported by future studies, LDN is a low dose of an already safe medication.
The risk of trying LDN therapy will be minimal for many people. In order to use LDN safely, patients should still continue with traditional treatments prescribed by their doctor. LDN may be considered to be an alternative therapy, similar to taking supplements, where the evidence has not been fully established, regarding their effectiveness in a particular area.
There have been claims that LDN may help with anxiety.
That being said, there are people in the low dose naltrexone community who claim that LDN does help with anxiety. Considering the fact that the treatment is far less toxic compared to many psych drugs on the market, including benzodiazepines and antidepressants, it may be worth a try.
However, for people experiencing symptoms of anxiety or depression, the first step to addressing these conditions should be to see a licensed mental health professional, including a doctor of psychology, and a psychiatrist.
Especially for people with a depressive disorder or suicidal ideation, it would not be a good idea to count on a treatment response with low dose naltrexone. Suicidal ideations should be treated like a medical emergency, similarly to symptoms of heart attack or stroke.
While LDN may provide some benefits for various chronic disease symptoms, not everyone will respond the same. Additionally, there should be more clinical trials to demonstrate the efficacy, or lack of efficacy of LDN in treating anxiety, or other conditions.
Does full dose naltrexone relieve anxiety when it is used to treat opioid use disorder or alcohol use disorder?
Naltrexone is an effective medication that is proven to help people stay off opioids and to help people to get their drinking under control or to quit drinking. But, does it help these patients with anxiety?
While there may be some direct effect on reducing anxiety, due to the activity of naltrexone on the kappa opioid receptor, naltrexone therapy will likely help to reduce anxiety in other ways as well. Many people with addictions to either alcohol or opiate drugs experience anxiety, especially during their time of active addiction.
Imagine the feelings of stress for a heavy drinker who knows that they are causing problems for themselves and their family, yet, they cannot stop. An inability to stop, even with an awareness of self-harm, is one of the defining characteristics of addiction.
The same would apply to an opioid addict. While opioids and opiates may cover up emotional pain and anxiety temporarily, these feelings come back as soon as the drug wears off.
Living in active addiction is living life in survival mode.
It is a never ending cycle of lying, and scraping by, with an ongoing obsession with how to get more drugs or alcohol and how to use them without getting caught. Fitting active addiction into the activities of daily living is incredibly stressful. It means living in a state of high alert, with the sympathetic nervous system constantly firing.
The sympathetic nervous system is the fight or flight system that would have helped to protect us from dangerous predators in prehistoric times. Squirrels running around the neighborhood appear to have a high sympathetic tone, for good reason.
A squirrel must always be looking for another nut or berry to eat or store away. They are also always on the lookout for a competing squirrel or a dangerous predator, ready to swoop in and end their short life.
Human beings are not squirrels. Unless we are in a war zone, or living in a dangerous jungle, we should be able to relax much of the time, dealing with life’s challenges in a cool and collected manner.
We can go throughout the day, with the understanding that most of our interactions are not going to be life or death situations. While there are many annoyances, and issues that may seem like a big deal, we can learn to not get too upset over the little things.
Surviving through active addiction is stressful, and can cause significant anxiety.
For an active drug user, life is not so different from the life of the squirrel racing across the fence, or jumping from branch to branch in a tree. Drugs are dangerous, and using illegal drugs is a very real risk.
A person using opioids, for example, is risking their life, and risking arrest and imprisonment, on a daily basis. While alcohol is legal, alcoholics often find themselves in dangerous situations, whether it is driving drunk, or blacking out and losing control.
So, as you can imagine, if naltrexone is prescribed to help a person addicted to a deadly substance, their anxiety will be significantly reduced over time. As the person begins to adjust to life without using drugs or alcohol, they start to have a new perspective on life.
Discovering the peace of mind of recovery can help to relieve the anxiety caused by active addiction.
As their lives are now less about survival, and more about living and enjoying a fulfilling life of getting things done and helping others, anxiety will naturally improve. Is this due to naltrexone?
Indirectly, if naltrexone helps a person to quit using a substance, and they begin to live a better life, we can give the medication some credit for improving their mental health state. This includes credit for reducing anxiety and depression related to the stress of living in active addiction.
The efficacy of naltrexone, as LDN, or as a full strength monthly Vivitrol shot, or a daily full strength tablet, may be questionable for treating anxiety. Yet, it is clear that naltrexone can help with anxiety, and other mental health conditions, simply by helping a person to overcome an addiction.
Addictions are stressful, often causing severe anxiety. Naltrexone can help a person to quit drugs or alcohol and enter recovery, therefore, relieving them of the anxiety of surviving in active addiction.
For more information about naltrexone therapy, naltrexone side effects, and more, please look for our upcoming naltrexone podcast. Visit our podcast network page to find information about upcoming podcasts about topics such as naltrexone and low dose naltrexone.
