Vivitrol Side Effects, Uses, Interactions, and Precautions

Vivitrol is a brand-name prescription medication containing naltrexone, a medication that is used to treat opioid and alcohol use disorders. Since it is formulated as a monthly injection, Vivitrol is thought to be a much safer alternative to many other opioid treatment medications. Studies have also found that Vivitrol is just as effective as acamprosate, another alcohol treatment medication.[1] However, like any prescription medication, Vivitrol may cause side effects.
Learning about the Vivitrol side effects, uses, interactions, and risks can help patients better understand whether or not Vivitrol is right for them.

What is Vivitrol (Naltrexone XR)?

Vivitrol is a once-monthly injection of extended-release naltrexone. Naltrexone is an opioid antagonist that is used to treat opioid and alcohol dependence after detox.[2] Similarly, the Vivitrol shot is also used for people who are recovering from opioid or alcohol addiction.

Before taking Vivitrol, patients must abstain from alcohol and stop taking opioids for at least 7-10 days prior to their first injection. It should also always be used in combination with counseling, education, and support groups.

As an injection that must be administered by a certified health professional in the buttocks, Vivitrol has little to no risk for abuse. And, since it is given once a month, patients don’t have to worry about keeping up with a daily pill.

Vivitrol Side Effects

Vivitrol may cause side effects, but most are minor and subside within a few days. The most common side effect reported among people taking Vivitrol is redness or irritation at the injection site. Fortunately, these symptoms usually subside within days or weeks and are considered completely normal.[2]

Other common side effects of Vivitrol include:

• Headache
• Nausea
• Dizziness
• Anxiety
• Restlessness
• Nervousness
• Fatigue
• Irritability
• Constipation
• Increased thirst
• Decreased appetite
• Weakness
• Muscle or joint aches
• Decreased sex drive
• Difficulty having an orgasm
• Insomnia
• Impotence

It is important that Vivitrol is administered by a medical professional who can monitor for potential side effects. The physician should also ensure that the patient has fully detoxed from opioids or alcohol before receiving his or her first injection. This is because administering Vivitrol while traces of opioids are still in the system can cause the patient to experience withdrawal symptoms.

Taking Vivitrol too soon can cause:

• Stomach cramping
• Restlessness
• Runny nose
• Muscle aches
• Joint or bone pain

Other less common, yet more severe side effects of Vivitrol may include:

• Irregular or fast heartbeat
• Suicidal thoughts
• Shortness of breath
• Difficulty breathing
• Chest pain
• Sores or blisters at the injection site

Patients who experience any of these symptoms should seek medical attention quickly.

In rare cases, some individuals may experience an allergic reaction. While this is rare, possible signs of a reaction to Vivitrol are:[3]

• Itching
• Hives
• Rash
• Swelling
• Dizziness
• Difficulty breathing

A suspected allergic reaction to Vivitrol may also warrant immediate medical attention.

Vivitrol Drug Interactions

It is not recommended to take Vivitrol with other medications unless advised by a physician. Doing so may cause severe side effects or interactions.
Vivitrol may interact negatively with the following:

• Narcotic pain relievers (buprenorphine, hydrocodone, morphine, methadone, oxycodone, codeine, etc.)
• Heroin
• Alcohol

It is not recommended to take Vivitrol with other medications unless advised by a physician. Doing so may cause severe side effects or interactions.
Vivitrol may interact negatively with the following:

Risks & Precautions

When the time comes to discuss going to rehab and keeping your job with your boss, it’s important that you know your rights and are properly prepared for the conversation. People with addiction may face stigma and judgment in the workplace, making this conversation very intimidating. However, being honest with your boss about the issue can help them see your problem in a more positive light. Here are some tips on how to approach your boss about keeping your job during rehab.

• Risk of opioid overdose – Naltrexone blocks the effects of opioids, so some users may try to overcome the blocking effect by taking large amounts of opioids. This can easily lead to coma, overdose, or death.
• Risk of reactions at the injection site – Some people have reported severe injection site reactions, including intense pain, area feeling “hard” after injection, excess swelling, blisters, lumps, open wounds, dark scabs.
• Sudden opioid withdrawal – Vivitrol that is administered too early after the patient stops taking opioids can cause them to go into sudden opioid withdrawal. This can be serious and require inpatient hospitalization.
• Hepatitis or liver damage – In some patients, naltrexone can cause hepatitis or liver damage. Symptoms of this include jaundice, prolonged stomach pain, dark-colored urine, and fatigue.

The best way to avoid these risks when taking Vivitrol is to always follow the guidance provided by the prescribing physician.

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What signs might indicate a more serious reaction to Vivitrol?

While most people experience mild or temporary side effects, there are instances where symptoms can signal a more serious reaction that requires prompt medical evaluation. Recognizing these signs early helps ensure safety and appropriate care.

1. Persistent or worsening injection site issues such as intense pain, swelling, or open wounds that do not improve within several days.
2. Symptoms of liver dysfunction including persistent upper abdominal pain, dark urine, yellowing of the skin or eyes, or unusual fatigue.
3. Respiratory symptoms such as difficulty breathing, wheezing, or chest tightness that appear after an injection.
4. New or worsening mood symptoms such as marked depression or thoughts of self-harm that are not typical for the individual.

These kinds of reactions are not common, but they require timely evaluation by a healthcare provider to determine whether ongoing Vivitrol treatment is safe.

Understanding how Vivitrol interacts with opioid tolerance and overdose risk

A key clinical concern when using Vivitrol involves its interaction with the body’s opioid receptors and how this affects tolerance and overdose risk. Vivitrol is formulated with naltrexone, an opioid antagonist that blocks the effects of opioids by occupying receptor sites without producing opioid effects. This blockade protects against the euphoric and rewarding effects of opioids, but it does not eliminate physical dependence or protect against all risks associated with opioid use.

Prior to initiating Vivitrol, individuals must be fully detoxified from opioid substances because receiving the injection while opioids are still present can precipitate acute withdrawal. Furthermore, because opioid tolerance decreases over time while the receptor blockade is in place, individuals who discontinue Vivitrol or miss doses may be at increased risk of overdose if they resume opioid use at previously tolerated doses.

In addition, opioids taken to overcome the blockade can lead to serious injury, coma, or death; therefore, clinicians emphasize the importance of education on these risks and close monitoring. Collaborative care that includes regular assessment of mood, liver function, and overall medical status helps manage these complex interactions and supports safer long-term treatment outcomes for patients receiving Vivitrol.