Amidst the escalating opioid crisis, a recent study unveils a promising treatment alternative for individuals grappling with opioid use disorder.
Opioid use disorder (OUD) has become a pressing concern in the United States, affecting over two million individuals and contributing to an alarming annual death toll of around 80,000 due to opioid-related overdoses.
This ongoing epidemic has had a profound impact on the average life expectancy of Americans. While there are existing treatments available for OUD, such as methadone, buprenorphine, and naltrexone, the high rate of relapse among patients underscores the urgent need for improved therapeutic options.
A recent preclinical study conducted by scientists at Scripps Research suggests that suvorexant (Belsomra), a medication primarily used for treating insomnia, may hold potential as an effective treatment for opioid use disorder.
The study, which was published in the journal Frontiers in Pharmacology, focused on rats modeling OUD. The researchers observed that suvorexant not only reduced the intake of prescription opioids but also demonstrated a protective effect against relapse.
Should these findings prove applicable to human subjects in future clinical trials, the use of suvorexant could present a promising avenue for addressing the needs of the millions of individuals grappling with OUD.
The findings of the study indicate “that repurposing suvorexant could be a good strategy for reducing drug intake and blocking relapse in cases of prescription opioid abuse,” according to study senior author Rémi Martin-Fardon.
The lead author of the study was Dr. Jessica Illenberger, a postdoctoral research associate in the Martin-Fardon lab.
The exact mechanism by which suvorexant exerts its beneficial effects on opioid use disorder (OUD) remains somewhat unclear. However, its design aims to inhibit the activity of both orexin-1 and orexin-2 receptors in the brain.
These receptors, along with their binding partners known as orexin proteins, have primarily been studied for their involvement in regulating wakefulness, appetite, and overall arousal and alertness. Nevertheless, accumulating evidence over the past two decades suggests that orexin signaling also plays a role in sustaining drug dependency, indicating its potential as a promising target for treatment.
Suvorexant, approved by the U.S. Food & Drug Administration (FDA) in 2014 for treating insomnia, was the first drug to inhibit the activity of both orexin receptors.
Earlier this year, a study was published by Martin-Fardon and colleagues demonstrating the efficacy of suvorexant in reducing alcohol intake and preventing relapse in a rat model of alcohol use disorder.
In the new study conducted by the team, the focus was on investigating the potential of suvorexant in reducing consumption and preventing relapse in individuals with opioid use disorder (OUD), specifically in relation to the widely abused prescription painkiller oxycodone.
Although suvorexant is metabolized more rapidly in rats compared to humans, the researchers discovered that when oxycodone-dependent rats were administered the highest dose of suvorexant (20 mg/kg) half an hour before their oxycodone binge sessions, they exhibited significantly reduced self-administration of the opioid during the initial hour of each eight-hour session.
Subsequently, the researchers employed a relapse model wherein an auditory cue served as a reminder to long-abstinent rats of their past oxycodone binges. Typically, this cue triggers a resurgence of intense oxycodone-seeking behavior. However, the maximum dose of suvorexant completely inhibited this reinstatement in male rats and significantly mitigated its intensity in females.
According to Martin-Fardon, the observed weaker effect of the treatment in females was not unexpected. This aligns with the findings of numerous addiction studies, which indicate that females tend to be more severely impacted by opioid addiction. Specifically, in their episodes of excessive consumption, females ingested over twice the quantity of oxycodone compared to males, and their relapses were also more intense.
“If you were to treat people, you would have to consider whether the same dose of suvorexant would work equally well for men and women,” Martin-Fardon points out.
According to the researcher, the results suggest that suvorexant can effectively combat oxycodone use and relapse behavior in addicted individuals. Therefore, the potential benefits of studying the drug in clinical trials for oxycodone-dependent patients are significant.
To explore the possibility of suvorexant restoring normal sleep-wake patterns and preventing relapse in animal models of oxycodone addiction, the researcher is planning a follow-up preclinical study.
Meanwhile, other researchers have launched small-scale clinical trials of suvorexant as an adjunctive therapy for individuals with drug-use disorders.
Another study published in the PLOS ONE Journal conducted a review of existing research on physical activity interventions for treating substance use disorders. The review excluded studies solely focusing on tobacco use and included studies investigating the application of physical activity interventions in treating substance use disorders.
The review findings indicated that physical activity interventions led to positive improvements in physical, psychological, and life outcomes. Most patients preferred moderate levels of physical activity, including cycling, jogging, resistance exercises, walking, yoga, and tai chi. The interventions were associated with enhancements in aerobic capacity, symptoms of depressive and anxiety disorders, and overall quality of life.
The authors of the study suggest that although physical activity interventions appear promising in treating substance use disorders, further rigorous and extensive research is necessary in this field.
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