To start Naltrexone for AUD or OUD, abstinence from alcohol must be maintained for how long?

• A. 3-5 days
• B. 7-14 days
• C. 1-2 months
• D. 24-48 hours

Answer: (B)

Starting naltrexone requires a period of opioid abstinence to prevent precipitated withdrawal. Naltrexone blocks mu-opioid receptors; if opioids are still in the system, this abrupt blockade can trigger acute withdrawal, which can be dangerous and uncomfortable. A typical 7–14 days of opioid-free status is recommended before initiation to allow opioids to clear and withdrawal to resolve, maximizing safety and the medication’s effectiveness. This timing applies regardless of whether the patient has AUD or OUD. Note: the abstinence concern here is from opioids, not alcohol. If the patient is on methadone or buprenorphine, a supervised taper or conversion plan is needed, which may require a longer period before starting naltrexone.