What You Need to Know About Naltrexone Withdrawal Symptoms

Medication-assisted treatment (MAT) is a proven and effective approach for substance use disorders. Studies show it reduces the risk of relapse and overdose. This is particularly important because, in 2020 alone, approximately 100,000 Americans lost their lives to a drug overdose. In other words, MAT can potentially save thousands of lives. 

Naltrexone is an FDA-approved medication for opioid use disorder (OUD) — the most common cause of drug overdose worldwide — and alcohol use disorder. However, despite its effectiveness, naltrexone can precipitate withdrawal if users take the drug while opioids or alcohol are still in their system.

This article breaks down everything you need to know about naltrexone and its withdrawal symptoms. 

How Does Naltrexone Work?

Naltrexone is an opioid antagonist. This means it binds to and occupies opioid receptors, preventing opioids from attaching to them. At the same time, it also alters the hypothalamic-pituitary-adrenal axis suppressing cravings for alcohol. 

In other words, naltrexone blocks the alcohol and opioid pleasure centers in the brain. This decreases cravings for alcohol and opioids, preventing misuse and overdose. 

How is Naltrexone Administered?

Naltrexone is available as tablets that users can swallow. Healthcare practitioners can also administer naltrexone via an injection into the muscles.

How Long Does Naltrexone Remain in the System?

Half-life refers to the time it takes for the concentration of a medication in blood to decrease by half. When taken orally, naltrexone's half-life is 4 hours. On the other hand, its half-life is between 5-10 days when administered through an intramuscular injection.

Remember, these values vary between individuals based on their health and genetics.

Naltrexone for Opioid Use Disorder (OUD)

Naltrexone is a safe and FDA-approved treatment for OUD. A meta-analysis of approximately 700 patients shows naltrexone is significantly more effective than placebo in reducing opioid misuse. In addition, it reduces relapse frequency, improving patients' ability to hold down a job.

Currently, research is ongoing evaluating naltrexone in patients with multidrug-dependent misuse. So far, the results are promising.

Naltrexone for Alcohol Use Disorder

Like in OUD, naltrexone is a proven and FDA-approved treatment for alcohol use disorder. In trials on 1,383 patients dependent on alcohol, naltrexone was notably more effective than placebo. Patients on naltrexone reported lower alcohol intake and an increase in alcohol-free days.

Other research shows naltrexone's role in alcohol use disorder is dose-dependent. In other words, higher doses lead to a more significant reduction in heavy-drinking days. In addition, the treatment is more effective in individuals that abstain from alcohol for at least four days before starting naltrexone.

Other Naltrexone Uses:

Doctors use naltrexone off-label — with promising results — to treat many conditions. These include:

• Obesity
• Cholestatic pruritus
• Chronic pain
• Fibromyalgia
• Chronic fatigue syndrome
• Crohn's disease
• Connective tissue diseases such as Sjogren's syndrome
• Depression
• Post-traumatic stress disorder (PTSD)
• Cancer

What Causes Naltrexone Withdrawal?

Naltrexone itself does not cause any withdrawal symptoms. But it can precipitate withdrawal if taken by patients who already have opioids or alcohol in their system. This is because naltrexone displaces opioids and other endorphins by binding firmly to opioid receptors. The abrupt removal of opioids (and endorphins) from their receptors triggers withdrawal. 

Naltrexone Withdrawal Side Effects and Symptoms

Naltrexone withdrawal is rarely life-threatening. But patients should consult their healthcare provider if they experience any withdrawal symptoms. These include:

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How to Prevent Naltrexone Withdrawal?

Preventing withdrawal with naltrexone is straightforward. Both patients and healthcare providers can take several measures to avert withdrawal. These are:

• Research suggests patients must be opioid and alcohol-free for at least seven days before starting treatment with naltrexone.
• Patients must take a supervised 'naltrexone challenge test.' During this test, a healthcare practitioner will administer a low dose of naltrexone and monitor the patient for withdrawal symptoms in a controlled setting. The onset of withdrawal indicates a 'positive' test which requires delaying naltrexone treatment.
• Practitioners should assess the patient's liver and kidney function before and during treatment. The liver and kidney metabolize naltrexone, so any loss of function may need dose adjustments.
• Providers must assess injection sites for injuries, wounds, and inflammation before administering naltrexone.

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Naltrexone Withdrawal FAQs

Does Naltrexone Need to be Tapered off?

No. This is because abrupt naltrexone discontinuation does not cause withdrawal symptoms. 

Can I Skip a Day of Naltrexone?

Doctors do not recommend skipping doses of naltrexone because it can increase the risk of relapse. In addition, if users miss a dose, they should take the medication as soon as possible unless it is time for the next dose. In either case, doctors do not recommend taking two doses of naltrexone simultaneously.

Can you Stop Naltrexone Cold Turkey?

Yes, because naltrexone discontinuation does not cause withdrawal.

Is Naltrexone Addictive?

No. This is because naltrexone is an opioid antagonist that occupies opioid receptors without stimulating them.

Naltrexone Can Help You Overcome Substance Use Disorders

Naltrexone is a proven treatment for opioid and alcohol use disorder. At Confidant Health, we combine medications such as naltrexone with behavioral therapies to help you overcome substance use disorders. Reach out to one of our naltrexone prescribers today!