Buprenorphine: prospective novel therapy for depression and PTSD

Mental Health Distress Is Associated With Higher Pain Interference in Patients With Opioid Use Disorder Stabilized on Buprenorphine or Methadone

BACKGROUND

The relationships between opioid use disorder (OUD), chronic pain, and mental health distress are complex and multidirectional. The objective of this exploratory study was to examine the relationship between mental health conditions and Chronic pain severity and interference among patients stabilized on either buprenorphine or methadone.

METHODS

We report baseline data from a randomized trial of a mind-body intervention conducted at 5 outpatient clinics that provided either buprenorphine or methadone treatment. Validated scales were used to measure substance use, mental health distress, and pain severity and interference. Statistical analyses examined the relationship between mental health conditions and pain severity and interference.

RESULTS

Of 303 participants, 57% (n = 172) reported Chronic pain. A total of 88% (n = 268) were prescribed buprenorphine. Mental health conditions were common, with one-quarter of the sample screening positive for all 3 mental health conditions (anxiety, depression, and posttraumatic stress disorder [PTSD]). Compared to participants without Chronic pain, participants with Chronic pain were more likely to screen positive for moderate-severe anxiety (47% vs 31%); moderate-severe depression (54% vs 41%); and the combination of anxiety, depression, and PTSD (31% vs 18%). Among participants with Chronic pain, mental health conditions were associated with higher pain interference. Pain severity was higher among participants with mental health conditions, but only reached statistical significance for depression. Pain interference scores increased with a higher number of co-occurring mental health conditions.

CONCLUSIONS

Among individuals stabilized on either buprenorphine or methadone, highly symptomatic and comorbid mental health distress is common and is associated with increased pain interference. Adequate screening for, and treatment of, mental health conditions in patients with OUD and Chronic pain is needed.

Novel Pharmacological Targets of Post-Traumatic Stress Disorders

Post-traumatic stress disorder (PTSD) is a psychopathological condition with a heterogeneous clinical picture that is complex and challenging to treat. Its multifaceted pathophysiology still remains an unresolved question and certainly contributes to this issue. The pharmacological treatment of PTSD is mainly empirical and centered on the serotonergic system. Since the therapeutic response to prescribed drugs targeting single symptoms is generally inconsistent, there is an urgent need for novel pathogenetic hypotheses, including different mediators and pathways. This paper was conceived as a narrative review with the aim of debating the current pharmacological treatment of PTSD and further highlighting prospective targets for future drugs. The authors accessed some of the main databases of scientific literature available and selected all the papers that fulfilled the purpose of the present work. The results showed that most of the current pharmacological treatments for PTSD are symptom-based and show only partial benefits; this largely reflects the limited knowledge of its neurobiology. Growing, albeit limited, data suggests that the hypothalamic-pituitary-adrenal axis, opioids, glutamate, cannabinoids, oxytocin, neuropeptide Y, and microRNA may play a role in the development of PTSD and could be targeted for novel treatments. Indeed, recent research indicates that examining different pathways might result in the development of novel and more efficient drugs.

Sublingual buprenorphine/naloxone treatment is not affected by OPRM1 A118G and BDNF Va66Met polymorphisms, but alters the plasma beta-endorphin and BDNF levels in individuals with opioid use disorder

The study aimed to examine the genetic contribution to buprenorphine (BUP) treatment in individuals with opioid use disorder (OUD), with a specific focus on BDNF and OPRM1 genes. A total of 113 controls and 111 OUD patients receiving sublingual BUP/naloxone were enrolled. OPRM1 A118G and BDNF Val66Met polymorphisms were investigated by PCR-FRLP. Plasma BDNF and beta-endorphin levels were assessed by ELISA kits in both groups. Blood BUP levels were measured by LC-MS/MS and normalized with daily BUP dose (BUP/D). OPRM1 A118G and BDNF Val66Met polymorphisms didn't have an effect on plasma beta-endorphin and BDNF levels in OUD patients, respectively. Interestingly, OUD patients had significantly higher plasma BDNF and lower beta-endorphin levels compared to the controls (p < 0.001). A negative and significant correlation between plasma BUP/D and BDNF levels was found. Age onset of first use was associated with OPRM1 A118G polymorphism. The findings indicated that sublingual BUP/naloxone may increase plasma BDNF levels, but may decrease beta-endorphin levels in individuals with OUD. Plasma BDNF level seemed to be decreased in a BUP/D concentration-dependent manner.

Buprenorphine/naloxone versus methadone opioid rotation in patients with prescription opioid use disorder and chronic pain: study protocol for a randomized controlled trial

Background

Opioids are effective in pain-management, but long-term opioid users can develop prescription opioid use disorder (OUD). One treatment strategy in patients with OUD is rotating from a short-acting opioid to a long-acting opioid (buprenorphine/naloxone (BuNa) or methadone). Both BuNa and methadone have been shown to be effective strategies in patients with OUD reducing opioid misuse, however data on head-to-head comparison in patients with chronic non-malignant pain and prescription OUD are limited.

Methods

This two-armed open-label, randomized controlled trial aims to compare effectiveness between BuNa and methadone in patients with chronic non-malignant with prescription OUD (n = 100). Participants receive inpatient rotation to either BuNa or methadone with a flexible dosing regimen. The primary outcome is opioid misuse 2 months after rotation. Secondary outcomes include treatment compliance, side effects, analgesia, opioid craving, quality of life, mood symptoms, cognitive and physical functioning over 2- and 6 months follow-up. Linear mixed model analysis will be used to evaluate change in outcome parameters over time between the treatment arms.

Discussion

This is one of the first studies comparing buprenorphine/naloxone and methadone for treating prescription OUD in a broad patient group with chronic non-malignant pain. Results may guide future treatment for patients with chronic pain and prescription OUD.

Trial registrationhttps://www.trialregister.nl/, NL9781

Gestational buprenorphine exposure disrupts dopamine neuron activity and related behaviors in adulthood

Opioid misuse among pregnant women is rapidly increasing in the United States. The number of maternal opioid-related diagnoses increased by 131% in the last ten years, resulting in an increased number of infants exposed to opioids in utero and a subsequent increase in infants developing neonatal abstinence syndrome (NAS). The most prescribed treatment to combat maternal opioid use disorder is buprenorphine, a partial μ-opioid receptor agonist and κ-opioid receptor antagonist. Buprenorphine treatment effectively reduces NAS but has been associated with disrupted cortical development and neurodevelopmental consequences in childhood. Less is known about the long-term neurodevelopmental consequences following buprenorphine exposure in utero Previous research has shown that gestational buprenorphine exposure can induce anxiety- and depressive-like phenotypes in adult rats, suggesting that exposure to buprenorphine in utero may render individuals more susceptible to psychiatric illness in adulthood. A common pathology observed across multiple psychiatric illnesses is dopamine system dysfunction. Here, we administered the highly-abused opioid, oxycodone (10 mg/kg, i.p.) or a therapeutic used to treat opioid use disorder, buprenorphine (1 mg/kg, i.p) to pregnant Sprague Dawley rats from gestational day 11 through 21, then examined neurophysiological alterations in the mesolimbic dopamine system and dopamine-dependent behaviors in adult offspring. We found that gestational exposure to buprenorphine or oxycodone increases dopamine neuron activity in adulthood. Moreover, prenatal buprenorphine exposure disrupts the afferent regulation of dopamine neuron activity in the ventral tegmental area (VTA). Taken together, we posit that gestational buprenorphine or oxycodone exposure can have profound effects on the mesolimbic dopamine system in adulthood.Significance StatementThe opioid epidemic in the United States is a growing problem that affects people from all demographics, including pregnant women. In 2017, nearly 21,000 pregnant women reported misusing opioids during pregnancy, which can lead to many physiological and neurodevelopmental complications in infants. To combat illicit opioid use during pregnancy, buprenorphine is the priority treatment option, as it reduces illicit opioid use and alleviates symptoms of neonatal abstinence syndrome in infants. However, less is known about the long-term neurophysiological consequences of in utero opioid or buprenorphine exposure. Here, we demonstrate that both oxycodone and buprenorphine exposure, in utero, can result in aberrant dopamine system function in adult rats. These results provide evidence of potential long-lasting effects of opioid exposure during development.

Long-term follow-up assessment of opioid use outcomes among individuals with comorbid mental disorders and opioid use disorder treated with buprenorphine or methadone in a randomized clinical trial

AIMS

To investigate whether reduction in opioid use differs when treated by either buprenorphine-naloxone (BUP) or methadone (MET) among adults with comorbid opioid use disorder (OUD) and mental disorders.

DESIGN, SETTING AND PARTICIPANTS

In a randomized controlled trial, adults with OUD were randomized to 24 weeks of either BUP or MET treatment and were followed up in 3-yearly assessments. The present secondary analyses were based on 597 participants who completed all assessments.

MEASUREMENTS

The outcome measure was the number of days of using opioids per month during the follow-up period. The Mini-International Neuropsychiatric Interview (MINI) was used to classify participants into three groups: life-time mood disorder (n = 302), life-time mental disorder other than mood disorder (n = 114) and no mental disorder (n = 181). Medication treatment (BUP, MET, no treatment) during the follow-up period was a time-varying predictor.

FINDINGS

Based on zero-inflated Poisson (ZIP) mixed regression analysis, it was found that relative to no treatment, opioid use during the follow-up was significantly reduced by BUP [odds ratio (OR) = 0.12, 95% confidence interval (CI) = 0.07-0.21 for any use; risk ratio (RR) = 0.77, 95% CI =0.66-0.89 for days of use] and by MET [OR = 0.33, 95% CI = 0.25-0.45 for any use; RR = 0.78, 95% CI = 0.72-0.84 for days of use]. Relative to MET, BUP was associated with a lower likelihood of any opioid use among participants with mood disorders (OR = 0.52, 95% CI = 0.36-0.74) and for participants without mental disorder (OR = 0.37, 95% CI = 0.21-0.66) and fewer number of days using opioids (RR = 0.37, 95% CI = 0.25-0.56) among participants with other mental disorders.

CONCLUSIONS

Among adults with comorbid opioid use disorder and mental disorders, treatment with buprenorphine-naloxone produced greater reductions in opioid use than treatment with methadone.

The self-serving benefits of being a good host: A role for our micro-inhabitants in shaping opioids' function

Opioids are highly efficacious in their ability to relieve pain, but they are liable for abuse, dependence, and addiction. Risk factors to develop opioid use disorders (OUD) include chronic stress, socio-environment, and preexisting major depressive disorders (MDD) and posttraumatic stress disorders (PTSD). Additionally, opioids reduce gut motility, induce loss of gut barrier function, and alter the composition of the trillions of microbes hosted in the gastrointestinal tract, known as the gut microbiota. The microbiota are significant contributors to the reciprocal communication between the central nervous system (CNS) and the gut, termed the gut-brain axis. They have strong influences on their host behaviors, including the ability to cope with stress, sociability, affect, mood, and anxiety. Thus, they are implicated in the etiology of MDD and PTSD. Here we review the latest studies demonstrating that intestinal flora can, directly and indirectly, by affecting sociability levels, responses to stress, and mental state, alter the responses to opioids. It suggests that microbiota can potentially be used to increase the resilience to develop analgesic tolerance and OUD.

Inflammation-driven brain and gut barrier dysfunction in stress and mood disorders

Regulation of emotions is generally associated exclusively with the brain. However, there is evidence that peripheral systems are also involved in mood, stress vulnerability vs. resilience, and emotion‐related memory encoding. Prevalence of stress and mood disorders such as major depression, bipolar disorder, and post‐traumatic stress disorder is increasing in our modern societies. Unfortunately, 30%–50% of individuals respond poorly to currently available treatments highlighting the need to further investigate emotion‐related biology to gain mechanistic insights that could lead to innovative therapies. Here, we provide an overview of inflammation‐related mechanisms involved in mood regulation and stress responses discovered using animal models. If clinical studies are available, we discuss translational value of these findings including limitations. Neuroimmune mechanisms of depression and maladaptive stress responses have been receiving increasing attention, and thus, the first part is centered on inflammation and dysregulation of brain and circulating cytokines in stress and mood disorders. Next, recent studies supporting a role for inflammation‐driven leakiness of the blood–brain and gut barriers in emotion regulation and mood are highlighted. Stress‐induced exacerbated inflammation fragilizes these barriers which become hyperpermeable through loss of integrity and altered biology. At the gut level, this could be associated with dysbiosis, an imbalance in microbial communities, and alteration of the gut–brain axis which is central to production of mood‐related neurotransmitter serotonin. Novel therapeutic approaches such as anti‐inflammatory drugs, the fast‐acting antidepressant ketamine, and probiotics could directly act on the mechanisms described here improving mood disorder‐associated symptomatology. Discovery of biomarkers has been a challenging quest in psychiatry, and we end by listing promising targets worth further investigation.

Different molecular targets, one purpose – treatment of depression

Although vast scientific progress has been made, the current pharmacotherapy of depression is still not fully effective. In adults, depressive disorders are among the most common diseases in industrialized countries, impact upon all aspects of family and working life and significantly disturb social functioning. Moreover, increasingly, they affect children and teenagers.

Depressive disorders have a complex etiology. This includes a number of mechanisms that are not yet fully understood. Therefore, the current review concentrates on bringing to the foreground the many molecular areas involved in occurrence of this disease. The work highlights the notion that depression has a complex pharmacology and inevitably requires the adoption of individual pharmacotherapy. This manuscript concentrates on currently used drugs drawn from diverse therapeutic groups and presents new promising targets for the treatment of depression. This is a particularly important issue due to the continuous lack of effective therapy and the constant search for new drugs and molecular targets for its treatment.