Vivitrol Side Effects: Common Reactions, Serious Risks, and a Realistic Timeline

Vivitrol is an injectable form of naltrexone that can be used to help (1) people recover from alcohol dependence, and (2) avoid returning to opioid use after detoxification.[1,2] Starting Vivitrol may raise questions about its side effects.

The objective of this article is to assist the client with a detailed, factual understanding of naltrexone’s side effects. It will cover common side effects, as well as serious side effects.

The information provided in this article is intended for educational use only. It is not a substitute for personal medical advice provided by your licensed healthcare provider, who is familiar with your individual medical history.

What Vivitrol Does and Why People Experience Side Effects

Vivitrol is the brand name for naltrexone, which is an opioid antagonist. This means that it blocks opioid receptors in the brain and body and reduces the pleasurable effects of opioids and alcohol [1]. Naltrexone is not the “cure” for addiction to opioids or alcohol and is considered to be more effective when combined with therapy and support services for recovery.

Because naltrexone interacts with how the brain and body opioid receptors respond to substances, some people will have physical or emotional reactions as they adjust to using this medication [2].

Why Vivitrol Side Effects Vary from Person To Person

Not all people will have the same experience when taking naltrexone. The variables affecting how each person experiences side effects are: first injection vs. subsequent injections, overall health, liver health, new alcohol use, and opioid clearance status. If opioids are still in the patient’s body, naltrexone can trigger a sudden withdrawal, which is why screening and timing are essential [3] to consider when starting treatment with naltrexone.

Clinical providers monitor the patient during the month after the first injection of naltrexone. Clinical staff will closely monitor the patient’s vital signs, any change in mood or emotion, how the injection site is healing, various aspects of well-being, as well as any new symptoms (i.e. breathing difficulty, jaundice, etc.) that could indicate stress on the liver [4]or adverse reactions. If any concerns arise, the clinical provider will respond promptly.

Common Vivitrol Side Effects

The majority of naltrexone patients will experience mild to moderate side effects that improve within a few days.

Common Symptoms Reported By Vivitrol Patients

Patients who are treated with naltrexone report the following side effects [2]:

• Nausea
• Headaches
• Dizziness/light-headedness
• Daytime sleepiness/fatigue
• Vomiting
• Reduced appetite
• Joint pain/muscle cramps
• Difficulty sleeping
• Toothaches

Most of the symptoms mentioned above occur soon after receiving the first injection and improve over time.

Symptoms That Are Commonly Improved with Time

While nausea, headaches, and fatigue can persist for longer, they typically resolve within a few days to a couple of weeks after the first injection of naltrexone [5]. If the nausea, headache, or fatigue persists beyond this time frame and is affecting your daily activities, reach out to your prescribing provider. Your provider will work with you to identify if these symptoms are expected as you continue your treatment with naltrexone, to determine how to monitor the symptoms, and whether changes need to be made to your treatment plan.

For mild naltrexone-related symptoms (nausea, fatigue, headaches), patients can use self-care: stay hydrated, eat small, healthy meals, and get enough rest.

Serious Side Effects of Vivitrol

While less common, some side effects of naltrexone have the potential to become serious and may require immediate medical attention.

Severe Injection Site Reactions

Mild discomfort at the injection site is common; rarely, severe injection site reactions occur [4]. Severe injection site reactions can include severe pain, extreme swelling, infection, skin breakdown, or tissue necrosis, requiring medical evaluation.

Liver Damage & Hepatitis Warning

Naltrexone can affect the liver, particularly at higher doses or in people with pre-existing liver disease [6]. Symptoms that may signal liver problems include yellowing of the skin or eyes, dark urine, light-colored stools, persistent abdominal pain, or ongoing nausea. Any of these symptoms should be reported to a healthcare provider immediately.

Sudden Opioid Withdrawal Risk

If opioids were used recently, naltrexone can cause sudden and intense withdrawal symptoms [3]. This is why individuals must be opioid-free for a period of time before starting treatment unless medically managed in a supervised setting.

Risk of Opioid Overdose

Naltrexone blocks opioid effects, but trying to override that blockade by using large amounts of opioids can lead to overdose [5]. Additionally, after naltrexone wears off, opioid tolerance may be lower, increasing overdose risk if relapse occurs. This is a critical safety consideration discussed in treatment planning.

Serious Allergic Reactions

Rare but severe allergic reactions may include rash, facial or throat swelling, trouble breathing, chest pain, severe dizziness, or fainting [2]. These symptoms require emergency care.

Mood Changes and Depression

Some individuals report mood changes, including depression or suicidal ideation while taking naltrexone[4]. Any new or worsening mood symptoms should be taken seriously and discussed with a healthcare professional as soon as possible.

Injection Site Reactions – What You Should Know

What You Should Expect After An Injection

It is common to experience mild discomfort, tenderness, reddish color, and mild swelling at the injection site. These symptoms improve within a few days [5].

What You Should Report

Contact your provider if you notice increasing pain. Signs of an infection at the injection site that should be reported to the prescriber include spreading redness or warmth, drainage, fever, hardness that worsens over time, discoloration, an open area of skin, or any symptoms lasting more than approximately 2 weeks.

Differences Between Monthly Injections

Some individuals may have different reactions with subsequent naltrexone injections; some people may see a lessening of symptoms with each injection, while others may experience new side effects. Continual discussions with your treatment providers will usually enable you to continue taking naltrexone safely.

Risk Factors for Increased Side Effects

Alcohol Usage While Undergoing Treatment

Naltrexone is used for alcohol use disorder and opioid use disorder. People in recovery are advised to abstain from alcohol. Alcohol use while using naltrexone places an additional strain on the liver and may also lead to other overlapping side effects; as a result, your clinician will generally ask about your use of alcohol, as this will lessen your overall risk. The use of naltrexone for the treatment of alcohol use disorder will lessen the euphoria in response to alcohol. Trying to override the blunting of alcohol’s effects with more alcohol can lead to alcohol poisoning. Also, when no longer using naltrexone, the body will be less tolerant to alcohol, increasing the risk for alcohol overdose.

Having a History of Liver Disease or Certain Medications

If you have a history of liver disease or have taken prescription medications that have a documented interaction with naltrexone, there is an increased likelihood of experiencing side effects; therefore, a comprehensive medical assessment is necessary before prescribing naltrexone to minimize potential complications.

Recent Opioid Use History

If you have been using opioids recently, you may be at risk for experiencing increased symptoms of withdrawal or may already be in withdrawal from your last use. Therefore, being appropriately screened and receiving the injection at the appropriate time is vital to ensuring the best start to your treatment with naltrexone.

Be Prepared for Your Appointment: You should take with you a complete list of medications and supplements you are taking; be prepared to have an honest discussion about any alcohol you use, and the date of your most recent use of opioids.

What To Do If You Experience Side Effects

How to Manage Mild Effects at Home

In many cases, mild nausea, headaches, or soreness can be managed by resting, drinking fluids, and monitoring symptoms. An ice pack for a sore injection site is helpful. You must contact your healthcare provider if your symptoms worsen or do not improve.

When to Contact Your Healthcare Provider

If you experience any of the following symptoms, you should contact your healthcare provider immediately: vomiting (persistent), severe headaches, worsening injection-site symptoms or mood changes, especially thoughts of suicide.

When to Seek Emergency Medical Attention

If you experience any of the following severe or frightening symptoms, you should immediately seek emergency medical care: allergic reactions, difficulty breathing, chest pain, heart palpitations, fainting, or any other symptom that seems extreme.

How New Wave Recovery Center Helps Clients Using Medication-Assisted Treatment

At New Wave Recovery Center, we provide an individualized, comprehensive approach for each client. Clients who attend outpatient, half-day treatment, and day treatment receive counseling and evidence-based (research-validated) therapies like cognitive behavioral therapy (CBT), which focuses on identifying and changing unhelpful thoughts and behaviors, and dialectical behavior therapy (DBT), which helps people manage intense emotions and behaviors. These are combined with holistic recovery services.

The process of determining which medications work best for clients is conducted on an individual basis in conjunction with the prescribing clinician. Our goal is to provide clients with educational opportunities, ongoing monitoring, and open communication so they feel supported and informed throughout their treatment.

If you would like additional information about naltrexone or have concerns about side effects, our staff is available to help you explore your treatment options and understand what to expect. Working with qualified professionals can provide you with valuable information and support during your recovery journey.