Vivitrol (naltrexone extended release) is a brand-name prescription medication. The Food and Drug Administration (FDA) has approved it in adults to:

Vivitrol comes as a solution given by a healthcare professional as an intramuscular injection. It belongs to a group of medications called opioid antagonists.

For information about the dosage of Vivitrol, including its strength and how Vivitrol injections (shots) are given, keep reading. For a comprehensive look at Vivitrol, see this article.

This article describes the drug manufacturer’s typical dosing schedules for Vivitrol. But your doctor will prescribe the dose of Vivitrol that’s right for you.

Before you start taking Vivitrol, your doctor will discuss the best dosage for you. Be sure to tell your doctor about any other medical conditions you have or medications you take.

Vivitrol form

Vivitrol comes as a powder that’s mixed into a solution. A healthcare professional will give it as an intramuscular injection.

Vivitrol strength

Vivitrol comes in one strength: 380 milligrams (mg) per 4 milliliters (mL) of solution.

Typical dosages

Your doctor will prescribe the smallest dosage that provides the desired effect.

The following information describes dosages that are commonly used or recommended. However, be sure to take the dosage your doctor prescribes for you. They will determine the best dosage to fit your needs.

Dosage for alcohol dependence

The recommended dosage of Vivitrol for alcohol dependence is 380 mg given as an intramuscular injection once every 4 weeks. Your doctor or healthcare professional will inject the dose of Vivitrol into the muscle of your buttock.

Dosage for opioid dependence

The dosage of Vivitrol for opioid dependence is 380 mg given as an intramuscular injection once every 4 weeks. You will receive your dose of Vivitrol in your doctor’s office. The medication is injected into the muscle of your buttock by your doctor or healthcare professional.

Before starting Vivitrol, you should not take any opioids for at least 7 to 10 days. This is to prevent withdrawal symptoms, which can happen if you have recently taken opioids and then take Vivitrol.

In some cases, withdrawal symptoms can be serious and may require hospitalization. It’s important to tell your doctor when you last took an opioid medication so that they can determine when you should start taking Vivitrol.

Long-term treatment

Vivitrol is meant to be used as a long-term treatment. If you and your doctor determine that Vivitrol is safe and effective for you, you’ll likely take it long term.

You may have some questions about Vivitrol’s dosage before you start taking this medication. Below are some frequently asked questions. If you have additional questions about Vivitrol dosage, talk with your doctor before starting treatment.

Does Vivitrol come in an oral form, such as a pill? If so, what is the drug’s oral dosage?

Vivitrol does not come in an oral form. However, the active drug ingredient in Vivitrol, naltrexone, is available in an oral tablet. Naltrexone tablets are not extended release, which means that the drug needs to be taken every day to be effective.

Naltrexone tablets are approved to treat opioid or alcohol dependence. The dosage for naltrexone tablets is usually 50 mg taken by mouth once per day.

Vivitrol is the brand name for the injectable form of the drug naltrexone. This is an extended-release drug, which means it works over a period of 1 month to treat opioid or alcohol dependence.

If you are interested in taking naltrexone tablets instead of Vivitrol injections, talk with your doctor. In some cases, they may adjust your dose based on your specific treatment plan.

I’m switching from an oral drug to Vivitrol. How will my dosage change?

If you’re switching from an oral treatment to Vivitrol, your dosage may change. Be sure to talk with your doctor about the best way to switch from one medication to another. The best way to switch may be based on the medication you were taking before starting Vivitrol.

For example, if you’re taking oral naltrexone and would like to switch to Vivitrol, both drugs have the same active ingredients. Because of this, it may be easier to stop taking your tablets and receive your first dose of injectable Vivitrol. Your dose will likely change from taking tablets once per day by mouth to receiving an intramuscular injection once per month from a healthcare professional.

If you’re switching from another treatment, such as buprenorphine, Suboxone (buprenorphine/naloxone), or methadone, your doctor will recommend the best way to switch to Vivitrol.

In some cases, buprenorphine and buprenorphine/naloxone are taken more than once per day. If you switch to Vivitrol, you will only need an injection once per month.

Since Vivitrol is only injected once monthly, switching from an oral drug may help manage your opioid or alcohol dependence better. This is because you don’t have to worry about remembering to take your dose every day or even multiple times per day.

If you are interested in switching from your oral drug to Vivitrol, talk with your doctor about how your dosage may change.

Vivitrol comes as a powder that’s mixed into a solution. It’s given as an intramuscular injection into the muscle of your buttock by a healthcare professional once every 4 weeks.

Your doctor or healthcare professional will alternate the injection site. If your first dose of Vivitrol is in your left buttock, your next dose will be in your right buttock. This is so you don’t develop scar tissue in the injection area.

If you have any questions about the dosage and administration of Vivitrol, talk with your doctor or pharmacist.

Accessible drug labels and containers

If you’re having trouble reading your prescription label, talk with your doctor or pharmacist. Some pharmacies offer labels with large print, braille, or a code you scan with a smartphone to convert text to speech. If your local pharmacy doesn’t have these options, your doctor or pharmacist might be able to recommend a pharmacy that does.

If you miss your appointment to receive your dose of Vivitrol, you should schedule an appointment as soon as you remember. It’s recommended that you receive your next dose of Vivitrol as soon as possible after a missed dose.

To help make sure you don’t miss a dose, try using a medication reminder. Medication reminders can help you remember your appointment for your Vivitrol injection. Reminders can include setting an alarm or using a timer. You could also download a reminder app on your phone.

The dosages in this article are typical dosages provided by the drug manufacturer. If your doctor recommends Vivitrol for you, they will prescribe the dosage that’s right for you.

If you have questions about your dosage of Vivitrol, talk with your doctor.

Besides learning about dosage, you may want other information about Vivitrol. These additional articles might be helpful:

  • More about Vivitrol. For information about other aspects of Vivitrol, refer to this article.
  • Drug comparison. To find out how Vivitrol compares with Sublocade, see this article.
  • Details about your condition. For details about dependence on alcohol or opioids, this list of articles may be helpful.

Disclaimer: Medical News Today has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.