Naltrexone Dosing for Alcohol Craving
The recommended dose of naltrexone for reducing alcohol craving in patients with alcohol use disorder is 50 mg once daily orally, or alternatively 380 mg intramuscularly once monthly for the extended-release injectable formulation. 1, 2
Standard Oral Dosing Protocol
Start with 50 mg once daily after the patient has been abstinent from alcohol for at least 3-7 days and all withdrawal symptoms have completely resolved 3, 1
Some clinicians use a gradual initiation: 25 mg daily for days 1-3, then increase to 50 mg daily thereafter to minimize nausea 3, 1
Treatment duration should be 3-6 months, with consideration for extension up to 12 months based on clinical response 3, 1
Injectable Extended-Release Formulation
Vivitrol 380 mg intramuscularly once monthly is an alternative that may improve medication adherence compared to daily oral dosing 4, 2
The same timing requirements apply: patient must be abstinent and withdrawal-free before initiating 3
Critical Timing Requirements
Never initiate naltrexone during active alcohol withdrawal - this is a common and dangerous pitfall 3:
Naltrexone provides no benefit for withdrawal symptoms and delays appropriate benzodiazepine therapy 3
The patient must be completely opioid-free (including tramadol) for a minimum of 7-10 days before starting naltrexone to avoid precipitated withdrawal 1
Wait 3-7 days after last alcohol consumption and only after withdrawal management is complete 3
Mechanism and Expected Efficacy
Naltrexone functions as a competitive opioid receptor antagonist that blocks the euphoric effects of alcohol and reduces craving 4, 1
The number needed to treat to prevent return to any drinking is approximately 20, with a modest effect size of 0.15-0.2 2, 4, 5
In clinical trials, naltrexone reduced relapse rates from 54-60% (placebo) to 23-31% (naltrexone) when combined with psychosocial treatment 1, 6
Hepatotoxicity Concerns and Monitoring
Naltrexone undergoes hepatic metabolism and carries potential hepatotoxicity concerns, though this is uncommon at the standard 50 mg dose 2, 4
Obtain baseline liver function tests and monitor every 3-6 months during treatment 4, 3
Naltrexone is contraindicated in patients with acute hepatitis or decompensated cirrhosis 3
For patients with alcoholic liver disease, consider safer alternatives like baclofen (the only medication proven safe in cirrhotic patients) or acamprosate (no hepatic metabolism) 2, 3
Essential Contraindications
Active alcohol withdrawal syndrome 3
Current use of opioid medications for pain control 4
Acute hepatitis or decompensated cirrhosis 3
Patients requiring opioids should have oral naltrexone held for 2-3 days prior to elective procedures 4
Common Side Effects
Nausea is the most common adverse effect, occurring in a minority of patients 7, 8
Other side effects include headache, dizziness, and arthralgia 8
Serious side effects are uncommon when used at the standard 50 mg dose 1, 7
Integration with Comprehensive Treatment
Naltrexone is only effective as part of comprehensive treatment including psychosocial support, counseling, and mutual help groups like Alcoholics Anonymous 3, 8:
The medication supports abstinence and prevents relapse but does not work in isolation 1
Implement compliance-enhancing techniques for all treatment components, especially medication adherence 1
Naltrexone is not uniformly helpful to all patients and represents a modest improvement in conventional treatment outcomes 1