What is the use of Naltrexone (opioid receptor antagonist) for alcohol dependence?

From the Guidelines

Naltrexone is not recommended for patients with alcoholic liver disease (ALD) due to the risk of toxic liver injury, but it can be effective in reducing excessive drinking and recurrence rates in patients with alcohol dependence without ALD. When considering the use of naltrexone for alcohol use disorder, it is essential to weigh the potential benefits against the risks, particularly in patients with liver disease. According to the study by 1, naltrexone decreases the concentration of dopamine in the brain and dampens activation of the reward pathway by alcohol, thereby decreasing excessive drinking and recurrence rates and increasing abstinence duration in patients with alcohol dependence. However, the same study notes that naltrexone is not recommended in patients with ALD due to the risk of toxic liver injury. In terms of dosage, the study by 1 recommends starting with 25 mg during the first 1-3 days and increasing to 50 mg thereafter, with a typical total treatment period of 3-6 months, but this can also last for up to 12 months. It is also important to consider the results of the systematic review and network meta-analysis by 2, which found that naltrexone is one of the medications recommended by NICE for clinical effectiveness in maintaining abstinence in patients with alcohol dependence. Some key points to consider when prescribing naltrexone include:

• Patients should be abstinent from alcohol for at least 3-7 days before starting naltrexone
• Liver function tests should be performed before starting naltrexone to assess the risk of liver damage
• Naltrexone can cause common side effects such as nausea, headache, dizziness, and fatigue, which typically improve over time
• The medication is contraindicated in patients taking opioid medications or with acute hepatitis or liver failure
• Treatment duration varies, but many patients benefit from taking naltrexone for 3-12 months or longer.

From the FDA Drug Label

Naltrexone hydrochloride is a pure opioid antagonist. It markedly attenuates or completely blocks, reversibly, the subjective effects of intravenously administered opioids. The mechanism of action of naltrexone hydrochloride in alcoholism is not understood; however, involvement of the endogenous opioid system is suggested by preclinical data. Naltrexone hydrochloride, an opioid receptor antagonist, competitively binds to such receptors and may block the effects of endogenous opioids Opioid antagonists have been shown to reduce alcohol consumption by animals, and naltrexone hydrochloride has been shown to reduce alcohol consumption in clinical studies. The efficacy of naltrexone hydrochloride as an aid to the treatment of alcoholism was tested in placebo-controlled, outpatient, double blind trials. These studies used a dose of naltrexone hydrochloride tablets 50 mg once daily for 12 weeks as an adjunct to social and psychotherapeutic methods when given under conditions that enhanced patient compliance Naltrexone hydrochloride tablets USP 50 mg is indicated in the treatment of alcohol dependence and for the blockade of the effects of exogenously administered opioids.

Naltrexone use for alcohol: Naltrexone is used as an aid to the treatment of alcohol dependence. It is indicated for the treatment of alcohol dependence and has been shown to reduce alcohol consumption in clinical studies 3, 4, 5. The recommended dose is 50 mg once daily for 12 weeks as an adjunct to social and psychotherapeutic methods.

• Key points: + Naltrexone is a pure opioid antagonist + It blocks the effects of endogenous opioids + It reduces alcohol consumption in clinical studies + It is indicated for the treatment of alcohol dependence + The recommended dose is 50 mg once daily for 12 weeks

From the Research

Naltrexone Use for Alcohol Dependence

• Naltrexone is a broad opioid-receptor antagonist that has been approved by the United States of America Food and Drug Administration for the treatment of alcohol dependence 6.
• Studies have shown that oral naltrexone can significantly reduce the risk of relapsing to heavy drinking compared to placebo, with a modest effect size of .15 to .2 6, 7.
• Naltrexone works by blocking the pleasurable effects or "high" associated with alcohol drinking, which can help prevent the return to clinically significant drinking 7, 8.
• The most common side-effects of naltrexone include nausea and vomiting, but it does not appear to be hepatotoxic at the recommended dosage of 50 mg/day 6, 7, 8.

Combination Therapy with Naltrexone

• Naltrexone can be used in combination with other medications, such as acamprosate, for the treatment of alcohol dependence 9, 10.
• The combination of acamprosate and naltrexone has been shown to be safe and effective in clinical studies, and may offer an advantage for some patients 9, 10.
• However, the use of combination therapy is not common in clinical practice, and more research is needed to fully understand its benefits and risks 9.

Treatment Duration and Predictors of Response

• The length of treatment with naltrexone has not been well studied, but many clinicians recommend one year of treatment 6.
• Efforts are underway to identify predictors of naltrexone response, but to date, no predictor has achieved clinical utility 6.
• Further research is needed to refine the role of naltrexone in the treatment of alcohol dependence and to identify the most effective treatment strategies 6, 10.