Elmosalamy 2025: naltrexone shot vs tablets, a meta-analysis

What they tested

The authors searched MEDLINE, Embase, Cochrane, APA PsycInfo and Scopus on 1 October 2024 for studies in adults with substance use disorders that compared extended-release naltrexone, a monthly injection, with oral naltrexone. They looked at staying on treatment, hospital admissions and emergency department visits.

Of 1,116 studies screened, 15 met the criteria: 3 open-label randomized trials (340 people), where everyone knew which treatment they got, and 12 retrospective studies (18,695 people) based on past records. All were in alcohol or opioid use disorder, and 7 could be pooled.

What they found

Treatment persistence, staying on the medicine, was higher with extended-release naltrexone at 3 months (OR 1.43; 95% CI 1.04 to 1.96) and at 6 months (OR 1.96; 95% CI 1.37 to 2.81).

There was no significant difference in hospital admissions (OR 0.69) or emergency department visits (OR 1.17).

The reviewers found no comparisons of the two forms in any substance use disorder other than alcohol and opioids.

Limits

• Only 3 small open-label randomized trials were included. Most data came from retrospective records, where people who chose the shot may differ from those who chose tablets.
• The review measured staying in treatment and hospital use, not drinking or opioid use.

What it means if you're considering naltrexone

For someone choosing between the monthly shot and daily tablets, this review suggests people tend to stay on the shot longer. It doesn't show that the shot cuts drinking more than the tablets, and the site's Vivitrol comparison notes the shot costs far more.