NALTREXONE INJECTION AND VIVITROL

On this page, you’ll discover:

• - What a naltrexone injection is and how it works.
• - The difference between Vivitrol® (the US brand name for an extended-release naltrexone injection) and other forms of naltrexone.
• - How to choose between a naltrexone injection and a naltrexone implant.
• - Whether this treatment option may be right for you.
  

What is a Naltrexone Injection?

For patients who wish to avoid the surgical procedure associated with implant insertion, a naltrexone injection provides an alternative treatment option. It is a long-acting, prolonged-release formulation designed to help reduce the risk of relapse following opioid or alcohol detoxification.

Once administered, the medication is released gradually into the bloodstream over approximately one month. This helps maintain therapeutic levels of naltrexone in the body, allowing it to block the effects of opioid drugs and, for people with alcohol use disorder, reduce cravings and the rewarding effects associated with alcohol.

Because some injectable formulations are highly concentrated and designed for slow absorption, the solution may be quite thick (viscous), which can make administration feel different from a standard injection.

What is a Vivitrol® shot?

A Vivitrol® shot has the same therapeutic effect as the long-acting naltrexone injections because both contain naltrexone as the active ingredient. Developed by the US pharmaceutical company Alkermes Inc. following many years of research, Vivitrol® uses a specialised polymer-based formulation. Unlike a standard liquid injection, it is a prolonged-release microsphere formulation of naltrexone designed to release medication gradually over approximately four weeks (one month).

Vivitrol uk Composition and Administration

Vivitrol® is supplied as a sterile, off-white to light tan powder containing 380 mg of naltrexone per vial. The naltrexone is incorporated into a 75:25 polylactide-co-glycolide (PLG) polymer matrix that allows gradual release of the medication.

Before administration, the medication must be prepared by a healthcare professional:

• Preparation: The microsphere powder is mixed with a clear, colourless diluent solution containing carboxymethylcellulose sodium salt, polysorbate 20, sodium chloride, and water for injection.
• Administration: Once the powder has been fully suspended, it is administered as a deep intramuscular (IM) gluteal injection.
• Safety equipment: Due to the specialised formulation, the injection should be administered using the manufacturer-supplied safety needle and components included with the product.

Further information: You can read more about the development and clinical research behind Vivitrol® in this dedicated article.

Should I choose a naltrexone injection (Vivitrol®) or an implant?

When deciding on long-acting relapse prevention, patients often compare naltrexone injections—including Vivitrol® (the US brand name for prolonged-release naltrexone)—with naltrexone implants. Both Vivitrol® and other naltrexone injections contain the same active ingredient and are designed to work in the same way. The main differences lie in the delivery method and duration of action when compared with an implant.

Advantages of an injection (Vivitrol®) over an implant

The primary benefit of choosing an injection over an implant is that it avoids the need for a minor surgical procedure:

• - No surgery required: The injection is administered in a standard treatment room, without the need for local anaesthetic or a surgical theatre.
• - No post-treatment recovery: There are no stitches to remove, wound dressings, or surgical scars associated with implant insertion.
• - No implanted material: Because no device is placed under the skin, there are no implant-related complications associated with having a foreign material in the body.

Disadvantages to consider

• - Monthly commitment: The opioid-blocking effect of the injection lasts for approximately four weeks, meaning treatment needs to be repeated monthly. Implants, by contrast, may provide protection for several months, depending on the type used.
• - Discomfort during administration: Because the prolonged-release solution is highly concentrated and viscous (thick), the intramuscular injection may feel uncomfortable during administration.

Is a naltrexone injection or Vivitrol® right for me?

Choosing the right treatment option depends largely on your current stage of recovery, your lifestyle, and your long-term goals. A long-acting naltrexone injection can be an effective treatment option, but it is not suitable for everyone.

Who is this treatment best suited for?

A prolonged-release injection may be suitable for individuals who:

• Prefer not to take daily medications: If you find it difficult to remember daily tablets, or feel that taking medication every day becomes a burden, a monthly injection can remove this challenge.
• Have completed detoxification: Naltrexone is an opioid antagonist. This means you must be completely free from opioids (including prescription opioid painkillers, opioid substitution treatments such as methadone or buprenorphine, and illicit opioids) before starting treatment. The required opioid-free period is usually at least 7–10 days, although this may vary depending on individual circumstances.
• Want an additional safety net: The injection provides continuous release of medication for approximately four weeks, allowing you to focus on recovery, therapy, and counselling.

When might it not be suitable?

This treatment may not be suitable if you are currently using opioids, as taking naltrexone while opioids are still present in your body can trigger sudden and severe withdrawal symptoms It may also not be appropriate for people with significant liver impairment, as naltrexone is metabolised by the liver.

Take the next step: Every recovery journey is unique. To determine whether a naltrexone injection is suitable for your situation, a comprehensive medical assessment with a qualified clinician is required.

Feel free to mail us at ask@refindyourway.com with any further questions.

Medical Disclaimer: The information on this page is for educational purposes only and should not replace professional medical advice. Always consult with your doctor or a qualified healthcare professional before making any medical decisions or starting any new treatment.