When should Vivitrol (naltrexone) be prescribed to patients with a history of alcohol or opioid dependence?

When to Prescribe Vivitrol (Naltrexone)

Vivitrol (injectable naltrexone) should be prescribed to patients with alcohol or opioid dependence who are fully detoxified, motivated to maintain abstinence, and are participating in a comprehensive treatment program that includes counseling and support. 1

Patient Selection Criteria

Essential Prerequisites

• Patient must be completely opioid-free for 7-10 days before starting Vivitrol (minimum 7-10 days for short-acting opioids) 2
• Patients transitioning from buprenorphine or methadone may need to be opioid-free for up to 2 weeks 2
• Liver function tests should be normal or only mildly elevated 1
• Patient should be motivated to maintain abstinence 1
• Patient should be engaged in a comprehensive treatment program that includes counseling 1

Ideal Candidates for Vivitrol

1. For Alcohol Dependence:

   • Patients who have achieved abstinence but are at high risk for relapse 1
   • Patients who have difficulty with medication compliance (monthly injection vs. daily oral medication) 1
   • Patients who have failed previous attempts at abstinence with counseling alone 1

2. For Opioid Dependence:

   • Motivated populations who cannot or do not wish to take continuous opioid agonist therapy 1
   • Healthcare professionals with opioid dependence 1
   • Patients who have completed opioid detoxification 2
   • Patients at risk for poor compliance with daily oral medication 3

Contraindications and Cautions

Absolute Contraindications

• Current opioid use or dependence (will precipitate severe withdrawal) 2
• Acute opioid withdrawal 2
• Failed naloxone challenge test 2
• Need for opioid pain management 1
• Severe hepatic impairment 2

Relative Contraindications

• Moderate hepatic impairment (dose adjustment may be needed) 2
• Renal impairment (use with caution) 2
• History of depression or suicidality (monitor closely) 2
• Pregnancy (insufficient safety data) 2

Administration Protocol

1. Pre-Treatment Assessment:

   • Confirm opioid-free status (7-10 days minimum) 2
   • Consider naloxone challenge test if opioid use history is uncertain 2
   • Baseline liver function tests 1

2. Dosing:

   • Vivitrol 380 mg intramuscular injection every 4 weeks 1
   • Alternative: oral naltrexone 50 mg daily (or 100 mg Monday/Wednesday, 150 mg Friday) 1

3. Monitoring:

   • Liver function tests every 3-6 months 1
   • Monitor for depression and suicidal ideation 2
   • Assess treatment response and continued motivation 1
   • Be aware that naltrexone levels may drop toward the end of the dosing interval 4

Important Clinical Considerations

Potential Pitfalls

• Risk of overdose: Patients who discontinue Vivitrol have decreased opioid tolerance and are at high risk for overdose if they return to previous opioid use 1
• Precipitated withdrawal: Failure to ensure complete opioid abstinence before administration can result in severe withdrawal requiring hospitalization 2
• Hepatotoxicity: While rare at therapeutic doses, monitor liver function 1, 2
• Breakthrough use: Some patients may attempt to overcome the opioid blockade by taking large amounts of opioids, which can be fatal 2

Effectiveness Considerations

• Naltrexone has modest effect size (0.15-0.2 range) for reducing relapse to heavy drinking 5
• More effective for reducing heavy drinking than for maintaining complete abstinence 5
• Should always be used as part of a comprehensive treatment program that includes psychosocial support 1, 6
• Consider treatment duration of approximately one year, though optimal duration has not been well established 5

Integration with Other Treatment Modalities

• Combine with behavioral therapies for best outcomes 1
• Consider referral to mutual help meetings (AA, NA, SMART Recovery) 1
• For patients with co-occurring psychiatric disorders, ensure appropriate treatment of these conditions 1

By following these guidelines, Vivitrol can be an effective component of treatment for alcohol and opioid dependence, particularly for patients who are highly motivated and have difficulty with medication compliance.