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Naltrexone Microspheres

Pronounced

"nal-TREX-own"

Uses

This medication is used to treat alcohol abuse. It is used only in people who have been able to stop drinking for some time before starting treatment with naltrexone. You should not be drinking when you start naltrexone. It can help people drink less alcohol or stop drinking altogether. Naltrexone works in the brain to decrease the desire to drink. It does not work like some other treatments for alcohol abuse (such as disulfiram). It will not make you sick when taken with alcohol.

This medication is also used to prevent relapse to opioid abuse, after opioid detoxification. It works by blocking the action of opioids. This medication must not be used in people currently taking opiates, including methadone. Doing so can cause sudden withdrawal symptoms.

Naltrexone belongs to a class of drugs known as opiate antagonists. It is used as part of a complete treatment program for alcohol or opioid abuse (such as counseling, 12-step program, lifestyle changes).

Ask your doctor or pharmacist if you should have naloxone available to treat opioid overdose. Teach your family or household members about the signs of an opioid overdose and how to treat it.

How to Use This Medication

Read the Medication Guide provided by your pharmacist before you start using naltrexone and each time you get a refill. If you have any questions, ask your doctor or pharmacist.

Before you receive this medication, you should have a urine test to check for recent opiate drug use. Your doctor may give you another medication (naloxone challenge test) to check for opiate use. Do not use alcohol/any opiates for at least 7 days before starting naltrexone. You may need to stop certain opiate drugs (such as methadone) 10 to 14 days before starting naltrexone.

This medication is injected into a muscle in the buttock by a health care professional. It is given as directed by your doctor, usually once a month.

The dosage is based on your medical condition and response to treatment. Your doctor may start you at a lower dose and monitor you for any side effects or withdrawal symptoms before increasing your dose.

To get the most benefit from this medication, use it regularly and continue your treatment program. To help you remember, mark your calendar with the days you need to receive this drug and/or be treated.

Tell your doctor if you start drinking alcohol again or start using drugs.

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Drug information is selected from data included with permission and copyrighted by First DataBank, Inc. This is a summary and does not contain all possible information about this product. For complete information about this product or your specific health needs, ask your healthcare professional. Always seek the advice of your healthcare professional if you have any questions about this product or your medical condition. This information is not intended as individual medical advice and does not substitute for the knowledge and judgment of your healthcare professional. This information does not contain any assurances that this product is safe, effective or appropriate for you.

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Information expires December 2025.