From the Guidelines
Naltrexone therapy is indicated for patients with opioid use disorder (OUD) who are motivated to maintain abstinence after detoxification, as well as for those with alcohol use disorder (AUD) seeking to reduce drinking or maintain abstinence. The medication works by blocking the effects of opioid agonists, providing time for patients to consider the consequences of relapse and seek support 1.
Key Considerations for Naltrexone Therapy
- Naltrexone should only be initiated after patients have been completely detoxified from opioids, typically 7-10 days opioid-free, to avoid precipitating withdrawal.
- The oral formulation is typically dosed at 50mg daily, or 100 mg on Mondays and Wednesdays, and 150 mg on Fridays, while the extended-release injectable form (Vivitrol) is administered as a 380mg intramuscular injection monthly 1.
- Before starting naltrexone, patients should undergo liver function testing as the medication can cause hepatotoxicity, with follow-up tests recommended every three to six months 1.
- Naltrexone is contraindicated in patients currently using opioids, those in acute opioid withdrawal, patients with acute hepatitis or liver failure, and individuals with hypersensitivity to the medication.
Patient Education and Monitoring
- Patients should be informed that naltrexone will block the effects of any opioid pain medications, which is crucial for emergency situations.
- Naltrexone has been shown to be helpful in maintaining abstinence from opioids in motivated populations, such as healthcare professionals who cannot or do not wish to take continuous opioid agonist therapy 1.
From the FDA Drug Label
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. Treatment of Alcoholism A dose of 50 mg once daily is recommended for most patients Treatment of Opioid Dependence Treatment should be initiated with an initial dose of 25 mg of naltrexone hydrochloride. If no withdrawal signs occur, the patient may be started on 50 mg a day thereafter
The indications to start naltrexone therapy are:
- Alcohol dependence: 50 mg once daily
- Opioid dependence: initial dose of 25 mg, followed by 50 mg a day if no withdrawal signs occur
- Blockade of the effects of exogenously administered opioids: 50 mg once daily 2, 2, 2
From the Research
Indications for Naltrexone Therapy
Naltrexone, an opioid receptor antagonist, has several indications for its use, including:
- Treatment of alcohol dependence, as it has been shown to reduce the risk of relapsing to heavy drinking 3
- Management of opioid dependence, particularly in patients who have completed detoxification and are at risk of relapse 4, 5, 6
- Blocking the euphoric effects of exogenous administered opioids, making it useful for patients with a history of opioid abuse 4
Patient Selection
When considering naltrexone therapy, patient selection is crucial:
- Patients with alcohol dependence may benefit from naltrexone, especially those who have failed other treatments or have a high risk of relapse 3, 7
- Opioid-dependent patients who wish to continue withdrawal and abstinence must be encouraged to visit trained physicians and be warned about misuse of naltrexone 4
- Patients who have completed detoxification and are at risk of relapse may benefit from naltrexone therapy, particularly when combined with other medications such as buprenorphine 5, 6
Important Considerations
Before initiating naltrexone therapy, several factors should be considered:
- Naltrexone can cause acute and severe withdrawal symptoms in opioid-dependent patients, and its use should be carefully monitored 4
- The efficacy of naltrexone in reducing relapse to heavy drinking is modest, and its use should be combined with other treatments and support 3
- Naltrexone has been shown to be effective in reducing craving and drinking behavior, but its use may be associated with side effects such as nausea and hepatotoxicity 7