Naltrexone for long-term management of alcohol dependence

Naltrexone is an opioid antagonist; it is similar to naloxone but longer-acting and taken orally. Because naltrexone is taken once daily, it is often preferred for convenience as a first-line agent for long-term management of alcohol dependence. However, it is contraindicated in patients who require opioid therapy. Naltrexone blocks the effect of opioid analgesics and can cause opioid withdrawal. It is also contraindicated in patients with liver failure or acute hepatitis.

Naltrexone blocks endogenous opioid-mediated release of dopamine that activates a reward stimulus. In people with alcohol dependence, naltrexone attenuates the desire (craving) to drink and the pleasure response related to drinking; naltrexone reduces rates of relapse to heavy drinking and increases the number of abstinence days in these patientsKim, 2018Rosner, Hackl-Herrwerth, Leucht, Vecchi, , 2010Swift, 2015. It has no effect in patients with minimal or moderate alcohol intake. Alcohol-induced impairment is not affected by naltrexone.

Naltrexone is sometimes prescribed (with specialist advice) for use before an episode of drinking to reduce consumption, although it is not approved for this indicationSinclair, 2001. When used in this situation, naltrexone is only taken pre-emptively (eg before entering a high-risk situation such as pub drinking) rather than every day.

Because naltrexone can cause liver toxicity, it is important to assess liver biochemistry before starting treatment, then monthly for the first 3 months, then (if normal) every 3 months.

Naltrexone may cause nausea, but a gradual dose increase and night-time dosing can reduce thisHaber, 2021.

If naltrexone is considered appropriate for long-term management of alcohol dependence, start after withdrawal symptoms have resolved (usually 3 to 7 days after the last drink); useCrowley, 2015:

Treatment is often continued for 3 to 6 months (less commonly 12 months) but duration should be determined individually, based on factors such as adverse effects, history of relapse and the patient’s social situation.