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What To Avoid When Taking Low-Dose Naltrexone: A Comprehensive Guide

From fibromyalgia to multiple sclerosis, low-dose naltrexone (LDN) has emerged as a novel treatment for an array of challenging medical conditions. It’s shown considerable promise in relieving pain, inflammation and other chronic health issues, but it also has the potential to cause harm if used improperly. Before starting LDN therapy, carefully review all of the information below to ensure you’re taking the proper precautions.

Overview of Low-Dose Naltrexone

Developed in the 1960s and approved by the FDA in 1984, naltrexone is most commonly used in the clinical treatment of opioid and alcohol use disorders. It works by suppressing the pleasurable effects of alcohol and opioids, which reduces cravings and helps patients remain abstinent. In conventional use, naltrexone is prescribed in doses of 50 mg per day.

In a typical LDN regimen, however, doses are often less than 5 mg. While the exact mechanism of action hasn’t yet been fully studied, such low doses are reported to increase the body’s natural production of endorphins. Low-dose naltrexone is also believed to ease inflammation by regulating the immune cells responsible for triggering the inflammatory response. These unique properties make LDN a potentially effective treatment option for a wide range of conditions, including:

  • Chronic pain and fibromyalgia
  • Chronic fatigue syndrome (CFS)
  • Autoimmune diseases
  • Chronic inflammatory diseases
  • Certain types of cancer

Since the doses are so small, LDN is generally considered to be safe and well-tolerated. Side effects are rare and typically mild. The most common issue is short-term insomnia, which is reported in about 8% of people. However, there are serious drug interactions and other factors to be aware of before beginning an LDN regimen.

Opioid-Based Medications and LDN

You should never take LDN if you’ve been using opioid medications, including narcotic pain relievers like codeine, morphine, hydrocodone and oxycodone. As a potent opioid antagonist, naltrexone blocks these drugs from binding to the receptors in your brain, which can rapidly precipitate or worsen the symptoms of opioid withdrawal. If you’re beginning LDN treatment, allow at least 10 to 14 days after your last dose of opioids.

Of course, you should also avoid taking these medications once you’ve started an LDN regimen. In addition to causing unpleasant side effects, this combination may prevent the low-dose naltrexone from working as intended. It usually takes several weeks for LDN to achieve optimal effects, so any setbacks can be very disruptive.

Alcohol Consumption and LDN

It’s generally recommended that you abstain from alcohol while taking naltrexone. The combination isn’t known to be hazardous on its own, but consuming alcohol may diminish the effectiveness of LDN. It can also exacerbate certain side effects, such as nausea, headache and dizziness.

What’s more, although naltrexone inhibits the “buzz” of being drunk, it doesn’t reduce alcohol’s other effects on the body. This can make it extremely difficult to accurately judge your level of intoxication. As a result, it’s easy to drink to excess and become dangerously impaired without realizing it.

Interactions With Other Medications

Most adverse reactions with low-dose naltrexone involve narcotic pain relievers, but it’s also important to be aware of other drug interactions. For instance, certain cough suppressants and antidiarrheal medications may contain codeine, hydrocodone or other opioids. While these medications are only available by prescription, it’s essential to check labels carefully and contact a health care professional if you have any questions.

While you won’t find most opioid medications on the shelves of your local drugstore, there’s one crucial exception. Loperamide, also known by the brand name Imodium, is a synthetic opioid commonly used to treat diarrhea. As such, it should not be taken immediately before or during LDN treatment. Another over-the-counter drug that may interact negatively with LDN is dextromethorphan, an active ingredient found in many popular cough medications.

Herbal Supplements and LDN

We often assume that natural substances are safer and less likely to cause drug interactions, but that’s not always the case. Perhaps the clearest example is kratom (Mitragyna speciosa), an herbal product from Southeast Asia that’s sometimes used as an alternative pain reliever and treatment for opioid addiction. Because this herb contains opioid-like compounds, it has been reported to cause withdrawal symptoms similar to prescription opioids in combination with naltrexone.

In addition, a number of common herbs and supplements interact with the same enzymes in your body that metabolize naltrexone. This includes St. John’s wort, Ginkgo biloba and Echinacea, among others. Although it’s not clear what effects these herbs may have, you should always tell your doctor about any supplements you’re taking to reduce the risk of interactions.

Recreational Drugs and LDN

Even in the very small doses used in a typical LDN regimen, combining naltrexone with recreational drugs is incredibly risky. Opium, hydrocodone, oxycodone, heroin, fentanyl and other related drugs may trigger the rapid onset of opioid withdrawal, which can sometimes be serious enough to require hospitalization. The same is true of certain medications used in treating drug addiction, such as methadone and buprenorphine.

Beyond the potential for acute withdrawal symptoms, LDN’s ability to block the euphoric effects of opioids can also be extremely dangerous. As with alcohol, some users may be tempted to continue taking larger doses to counteract the diminished “buzz.” This substantially increases the risk of accidental overdose, making it even more critical to treat any addiction issues if you’re considering LDN therapy.

Avoiding Abrupt Discontinuation

Naltrexone does not cause physical or psychological dependence and patients are not known to experience withdrawal upon sudden discontinuation. Nonetheless, you should never stop taking LDN abruptly without first consulting your doctor. Depending on your circumstances, doing so could cause a recurrence of your previous symptoms. In some cases, your physician may instead advise gradually tapering your dose until you can safely stop.

Special Medical Considerations With LDN

Whether you’re having surgery or sitting in the emergency room with a broken bone, it’s crucial that you always let your doctors know you’re taking LDN. This will ensure you aren’t accidentally given opioids when you require pain management. In fact, many doctors will provide a card you can carry on your person to alert medical personnel in case you’re ever incapacitated.

Naltrexone is labeled an FDA Pregnancy Category C drug, indicating that risk to the fetus cannot be ruled out. Research has shown that it can cross the placenta, but there’s little direct evidence of birth defects and other complications. Likewise, although small amounts of naltrexone are excreted in breast milk, this does not appear to be harmful. If you’re pregnant or breastfeeding, be sure to fully evaluate the risks and benefits of LDN treatment with your physician.

Low-dose naltrexone may also affect how certain other medical treatments work, so talk to your health care provider if:

  • You’ve received an organ transplant
  • You’re on immunosuppressive medications
  • You’re undergoing chemotherapy

The Importance of Regular Medical Check-Ups

Although LDN has shown promising results in treating a variety of conditions, it’s not an overnight solution. It’s important to be patient and attend all scheduled check-ups so that your doctor can monitor your progress. While not strictly necessary, keeping a journal of your symptoms can be invaluable in helping your doctor identify potential side effects and assess the efficacy of the treatment.

At such low doses, even very small changes can have significant impacts on how well you respond. As a relatively new treatment option, it often takes some tweaking to find the precise LDN regimen that works best for you.


It’s not quite a miracle cure, but low-dose naltrexone is an exciting option for many people suffering from chronic illnesses. However, it’s certainly not without risks. If LDN may be helpful to you, it’s critical to be open and honest with your doctor about any drug use or other issues that could impact your health and well-being. To learn more about LDN and how it can be used safely, call (833) 703-4357 to talk to the experts at Recreate Behavioral Health Network today.

Recommended Resources

Check out the following links for further reading and additional resources on the benefits, side effects, interactions and other safety considerations associated with low-dose naltrexone: