skip to main content
Washington State Institute for Public Policy
Back Button

Naltrexone implants

Substance Use Disorders: Medication-assisted Treatment
  Literature review updated December 2016.

Implantable naltrexone is an opioid antagonist that blocks the effects of opiates for opioid-dependent patients. Implants are inserted subcutaneously every six months. Patients do not develop tolerance or experience withdrawal symptoms when they stop taking the drug. Patients also receive drug counseling while using implants.
 
ALL
META-ANALYSIS
CITATIONS

Meta-analysis is a statistical method to combine the results from separate studies on a program, policy, or topic to estimate its effect on an outcome. WSIPP systematically evaluates all credible evaluations we can locate on each topic. The outcomes measured are the program impacts measured in the research literature (for example, impacts on crime or educational attainment). Treatment N represents the total number of individuals or units in the treatment group across the included studies.

An effect size (ES) is a standard metric that summarizes the degree to which a program or policy affects a measured outcome. If the effect size is positive, the outcome increases. If the effect size is negative, the outcome decreases. See Estimating Program Effects Using Effect Sizes for additional information on how we estimate effect sizes.

The effect size may be adjusted from the unadjusted effect size estimated in the meta-analysis. Historically, WSIPP adjusted effect sizes to some programs based on the methodological characteristics of the study. For programs reviewed in 2024 or later, we do not make additional adjustments, and we use the unadjusted effect size whenever we run a benefit-cost analysis.

Research shows the magnitude of effects may change over time. For those effect sizes, we estimate outcome-based adjustments, which we apply between the first time ES is estimated and the second time ES is estimated. More details about these adjustments can be found in our Technical Documentation.

Meta-Analysis of Program Effects
Outcomes measured No. of effect sizes Treatment N Effect sizes (ES) and standard errors (SE) Unadjusted effect size (random effects model)
ES SE Age ES p-value
Opioid use disorder
Clinical diagnosis of opioid use disorder or symptoms on a validated scale.
23 4 247 -0.734 0.046 23 -0.734 0.001

Citations Used in the Meta-Analysis

Krupitsky, E., Zvartau, E., Blokhina, E., Verbitskaya, E., Wahlgren, V., Tsoy-Podosenin, M., . . . Woody, G.E. (2012). Randomized trial of long-acting sustained-release naltrexone implant vs oral naltrexone or placebo for preventing relapse to opioid use disorder. Archives of General Psychiatry, 69(9), 973-981.

Kunøe, N., Lobmaier, P., Vederhus, J.K., Hjerkinn, B., Hegstad, S., Gossop, M., . . . Waal, H. (2009). Naltrexone implants after in-patient treatment for opioid use disorder: randomised controlled trial. The British Journal of Psychiatry, 194(6), 541-546.

Tiihonen, J., Krupitsky, E., Verbitskaya, E., Blokhina, E., Mamontova, O., Föhr, J., . . . Zwartau, E. (2012). Naltrexone implant for the treatment of polydrug use disorder: A randomized controlled trial. The American Journal of Psychiatry, 169(5), 531-536.

Tiurina, A., Krupitsky, E., Zvartau, E., & Woody, G. (2010). Long acting naltrexone implants for heroin use disorder. European Neuropsychopharmacology, 20(S1), S79-S80.