Naltrexone (oral: Revia® and generic; injectable: Vivitrol®) is an opioid antagonist. It blocks the effects of opioids by competitive binding at opioid receptors. Here is key information about this medication.
FDA-approved indications
1. Treatment of alcohol dependence
2. Blockade of effects of exogenously administered opioids in comprehensive treatment of opioid dependence
Dosage
A. Alcohol dependence
Oral: 50 mg once daily
Injectable: 380 mg IM every 4 weeks or once a month
B. Opioid dependence
Oral (standard regimen): 25 mg initially, and if no withdrawal symptoms occur then administer 50 mg next day and thereafter
Oral (supervised regimen):
a) 50 mg every weekday and 100 mg on Saturday or
b) 100 mg every other day or
c) 150 mg every third day
Injectable: 380 mg IM every 4 weeks or once a month
Patients (including those being treated for alcohol dependence) should be off all opioids, including opioid-containing medicines, for a minimum of 7 to 10 days before starting naltrexone in order to avoid precipitation of opioid withdrawal. Patients transitioning from buprenorphine or methadone may be vulnerable to precipitation of withdrawal symptoms for as long as two weeks. In some cases it may be helpful to perform naloxone challenge test to confirm that the patient has had an opioid-free period.
Dosage forms and strengths
Oral tablets: 50 mg scored (Revia® and generic); 25 mg and 100 mg (generic only)
Extended-release injectable suspension: 380 mg of naltrexone in a microsphere formulation and 4 mL diluent
Please refer to Prescribing Information (see link below) for complete discussion of dosage, administration, warnings and precautions, contraindications, etc.
Related Pages
Tips on using naltrexone extended-release injectable (Vivitrol®)
How to order, store, and administer naltrexone extended-release injection (Vivitrol®)
Five pearls for avoiding misuse or diversion of buprenorphine
Naloxone autoinjector (Evzio®) and intranasal spray (Narcan® nasal spray)
Tips for opioid dependent patients
False positive urine drug screen results: Principles and a table for reference
References
Naltrexone (Revia®) Prescribing Information
Naltrexone (Vivitrol®) Prescribing Information
Copyright 2016, Rajnish Mago, MD. All rights reserved. May not be reproduced in any form without express written permission.
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