Current status of opioid addiction treatment and related preclinical research

Abstract

Opioid use disorders (OUDs) are diseases of the brain with behavioral, psychological, neurobiological, and medical manifestations. Vulnerability to OUDs can be affected by factors such as genetic background, environment, stress, and prolonged exposure to μ-opioid agonists for analgesia. Two standard-of-care maintenance medications, methadone and buprenorphine-naloxone, have a long-term positive influence on health of persons with opioid addiction. Buprenorphine and another medication, naltrexone, have also been approved for administration as monthly depot injections. However, neither medication is used as widely as needed, due largely to stigma, insufficient medical education or training, inadequate resources, and inadequate access to treatment. Ongoing directions in the field include (i) personalized approaches leveraging genetic factors for prediction of OUD vulnerability and prognosis, or for targeted pharmacotherapy, and (ii) development of novel analgesic medicines with new neurobiological targets with reduced abuse potential, reduced toxicity, and improved effectiveness, especially for chronic pain states other than cancer pain.

Differences in receipt of opioid agonist treatment and time to enter treatment for opioid use disorder among specialty addiction programs in the United States, 2014-17

“…Moreover, variations in who receives OAT and time to enter treatment based on sociodemographic and institutional characteristics highlight further areas for further study and potential intervention. In addition, further research is needed regarding personalised approaches to characterising the inheritable factors which contribute towards heightened risk of OUD as well as potential avenues for more effective treatment [40]. Nevertheless, given the limitations of the TEDS-A dataset, we are unable to unravel the causal mechanisms which underlie these differences.…”

Atomic-Level Characterization of the Methadone-Stabilized Active Conformation of µ-Opioid Receptor

“…One of the most widely used effective treatments for opioid addiction ( Kreek et al, 2019 ) involves the prolonged prescription of methadone as an alternative to the abused opioid. Methadone is a synthetic opioid with a different chemical structure compared with other clinically prescribed opioids (e.g., morphine, oxycodone, fentanyl, etc.)…”

“…A MOR agonist like morphine and heroin, methadone has less abuse potential than these classic opioid drugs ( Kreek, 2000 ) and is an effective antinociceptive agent in patients with pain that do not respond to other analgesics ( Weschules and Bain, 2008 ). Although approximately 20%–40% of individuals drop out of methadone maintenance treatment ( Kreek et al, 2019 ), this treatment still has greater retention than buprenorphine maintenance, making one wonder what makes methadone so special.…”

<p><em>OPRM1</em> A118G Polymorphisms and Its Role in Opioid Addiction: Implication on Severity and Treatment Approaches</p>

“…Several genetic studies (primarily case-control studies) have been carried to determine the impact A118G variant both on the onset and treatment of opioid and other addictions. Outcomes are highly diverse in which some studies have shown a significant association of A118G with opioid addiction while other studies have failed to obtain such evidence 41. The probability to develop opioid addiction is less in Hispanic 118G carriers compared to individuals with African-American or Caucasian ethnic backgrounds 11.…”