Oral naltrexone has been shown to reduce alcohol consumption and craving in individuals with alcohol use disorder (AUD), yet evidence regarding the efficacy of the extended-release injectable formulation (XR-naltrexone) is limited. Researchers conducted a systematic review and meta-analysis of 7 randomized controlled trials evaluating 1500 adults with AUD receiving XR-naltrexone (150–400 mg) for 2–6 months or placebo, plus some form of behavioral therapy. The primary outcome was the pooled weighted mean difference
Comments: With a modest reduction in drinking days and heavy drinking days per month compared with psychosocial interventions and placebo alone, the results of this meta-analysis suggest that XR-naltrexone may have some efficacy for AUD treatment, especially with longer treatment duration. Further research is needed to determine the long-term efficacy of XR-naltrexone, its effects among an actively drinking population, and how it compares (e.g., efficacy and cost) with oral naltrexone.
Amphetamines are the second-most commonly used drug in the world and their use is rising in the US. There are currently no FDA-approved medications for treating methamphetamine use disorder (MUD). This multisite randomized controlled trial evaluated the efficacy and safety of extended-release naltrexone (380mg every 3 weeks) plus oral extended-release bupropion (450mg daily), compared with placebo for 6 weeks. The primary outcome was treatment response, defined as at least 3 out of 4 methamphetamine-negative urine drug tests over the last 2 weeks of the study.
The study enrolled 403 patients with moderate or severe MUD.
15% of eligible patients were randomized; 69% of the participants were men.
Overall, 13.6% of patients in the intervention group had a treatment response, compared with 2.5% in the placebo group; this translates to a number needed to treat of 9.
The most common adverse effects were gastrointestinal disorders, tremor, malaise, hyperhidrosis, and anorexia.
Comments: Medications that are accessible and effective are urgently needed to treat MUD. Behavioral treatments like cognitive behavioral therapy and contingency management show favorable benefit, although their access remains very limited. This trial demonstrates a possible new treatment for MUD; however, limiting factors may be cost of the treatments and patient preference, both of which were not assessed.
Researchers have begun testing drugs approved for other substance use disorders to treat people with methamphetamine addiction. Examples include naltrexone—which is used for the treatment of opioid use disorder—and bupropion, which helps people quit smoking.
Both treatments have shown some effectiveness when used alone to treat methamphetamine addiction. A research team led by Dr. Madhukar Trivedi at the University of Texas Southwestern Medical Center launched a clinical trial to see if a combination of the two might help more people quit.
Among adults with methamphetamine use disorder, the response over a period of 12 weeks among participants who received extended-release injectable naltrexone plus oral extended-release bupropion was low but was higher than that among participants who received placebo. (Funded by the National Institute on Drug Abuse and others; ADAPT-2 ClinicalTrials.gov number, NCT03078075..)