Search Results (891)

Substance-induced psychosis is a recognized clinical entity, commonly linked to cannabinoids, stimulants, hallucinogens, alcohol, and polysubstance use. These agents may provoke transient or persistent psychotic symptoms during intoxication or withdrawal. Opioids, however, constitute a noteworthy exception: psychosis is rarely observed during opioid intoxication, and emerging data suggest that opioid agonists might even exert antipsychotic-like effects. This article examines the paradoxical interaction between opioids and psychosis, with attention to clinical reports of psychotic symptoms arising following abrupt discontinuation of methadone or buprenorphine. In numerous cases, symptoms resolved swiftly after reintroduction of the opioid agonist, implying a neuromodulatory role. Opioids, unlike other substances of abuse, seem to lack intrinsic psychotogenic effects and may influence dopaminergic activity via kappa-opioid receptor antagonism and endorphinergic mechanisms. This challenges standard models of substance-induced psychosis and calls for a refined understanding of opioid pharmacodynamics in psychiatric contexts. In psychotic presentations among polysubstance users who also use opioids, restoring opioid agonist therapy should be prioritized, with antipsychotics reserved as second-line options—preferably agents with favorable receptor profiles. Where opioids are not involved, antipsychotics remain first-line, but should be applied judiciously, with efforts to taper when clinically appropriate. Full article

Tau protein is essential for the structural stability of neurons, particularly through its role in microtubule assembly and axonal transport. However, when abnormally hyperphosphorylated or cleaved, Tau can aggregate into insoluble forms that disrupt neuronal function, contributing to the pathogenesis of neurodegenerative diseases such as Alzheimer’s disease (AD). Emerging evidence suggests that similar Tau-related alterations may occur in individuals with chronic exposure to psychoactive substances. This review compiles experimental, clinical, and postmortem findings that collectively indicate a substance-specific influence on Tau dynamics. Alcohol and opioids, for instance, promote Tau hyperphosphorylation and fragmentation through the activation of kinases such as GSK-3β and CDK5, as well as proteases like caspase-3, leading to neuroinflammation and microglial activation. Stimulants and dissociatives disrupt insulin signaling, increase oxidative stress, and impair endosomal trafficking, all of which can exacerbate Tau pathology. In contrast, cannabinoids and psychedelics may exert protective effects by modulating kinase activity, reducing inflammation, or enhancing neuroplasticity. Psychedelic compounds such as psilocybin and harmine have been demonstrated to decrease Tau phosphorylation and facilitate cognitive restoration in animal models. Although the molecular mechanisms differ across substances, Tau consistently emerges as a convergent target altered in substance-related cognitive disorders. Understanding these pathways may provide not only mechanistic insights into drug-induced neurotoxicity but also identify Tau as a valuable biomarker and potential therapeutic target for the prevention or treatment of cognitive decline associated with substance use. Full article

The use of opioids for cancer-related pain is essential but poses significant challenges due to the risk of misuse and the development of opioid use disorder (OUD). This review takes a multidisciplinary perspective based on the current scientific literature to analyze the pharmacological mechanisms, classification, and therapeutic roles of opioids in oncology. Key risk factors for opioid misuse—including psychiatric comorbidities, prior substance use, and insufficient clinical monitoring—are discussed in conjunction with validated tools for pain assessment and international guidelines. The review emphasizes the importance of integrating toxicological, pharmacological, physiological, and public health perspectives to promote rational opioid use. Pharmacogenetic variability is explored as a determinant of treatment response and addiction risk, underscoring the value of personalized medicine. Evidence-based strategies such as early screening, psychosocial interventions, and the use of buprenorphine-naloxone are presented as effective measures for managing OUD in cancer patients. Ultimately, this work advocates for safe, patient-centered opioid prescribing practices that ensure effective pain relief without compromising safety or quality of life. Full article

Background: Heat therapy (HT) and electroacupuncture (EA) are widely utilized pain relief methods, but the analgesic mechanisms of their combined application remain unclear. Methods: In acetic acid (AA)-induced writhing test and complete Freund’s adjuvant (CFA)-induced inflammatory pain tests, mice received one of three treatments: EA at bilateral ST36, HT via a 45 °C heating pad, or the combination (EA + HT). To probe underlying pathways, separate groups were pretreated with caffeine, DPCPX (a selective adenosine A₁ receptor antagonist), or naloxone (an opioid receptor antagonist). Spinal expression of glial fibrillary acidic protein (GFAP) and phosphorylated p38 (p-p38) was examined by Western blot and immunofluorescence. Results: Both EA and HT individually reduced AA-induced writhing, with the combination (EA + HT) exhibiting the greatest analgesic effect. EA’s analgesic effect was reversed by caffeine and DPCPX and partially by naloxone, while HT’s effect was reversed by caffeine and DPCPX but was unaffected by naloxone. AA injection elevated spinal p-p38 and GFAP expression, which were attenuated by either EA or HT, with the most substantial suppression observed in the EA + HT group. In the CFA model, both treatments alleviated mechanical allodynia, while the combined treatment resulted in significantly greater analgesia compared to either treatment alone. Conclusions: EA combined with HT synergistically enhances analgesia in both AA and CFA pain models, accompanied by reduced spinal inflammation and astrocyte activation. EA’s analgesic effects appear to involve adenosine A₁ receptor pathways and, to a lesser extent, opioid receptor mechanisms, whereas HT’s effects involve adenosine A₁ receptor pathways. Full article

The diagnosis of opioid use disorder (OUD) is prevalent due to increased prescribing of opioids. Long-term oxycodone self-administration can lead to addiction-like behavioral responses in rats. Herein, we sought to identify molecular pathways consequent to long-term exposure to oxycodone self-administration. Towards that end, we used male Sprague Dawley rats that self-administered oxycodone for 20 days according to short-(ShA, 3 h) and long-access (LgA, 9 h) paradigms. LgA rats escalated their oxycodone intake and developed into 2 phenotypes, labeled Long-access High (LgA-H) and Long-access Low (LgA-L) rats, based on their escalation. RNA sequencing analysis revealed the LgA-H has significantly different DEGs in comparison to other groups. DAVID analysis revealed the participation of LgA-H DEGs in potassium transport. RT-PCR analysis of striatal samples validated the increased levels of potassium channels. Since these increases correlated with oxycodone intake, we believe potassium channels are potential targets for the treatment of oxycodone use disorder Full article

Background/Objectives: The consumption of opioids is a public health problem that significantly affects quality of life. In Spain, 7585 people are enrolled in the Methadone Maintenance Programme (MMP), which is an effective intervention with a low adherence rate. In this study, factors associated with the quality of life of MMP users, especially perceived social support and treatment adherence, were analysed. We hypothesised that low levels of adherence and social support would be associated with poorer quality of life. Methods: This was a cross-sectional observational study with an analytical approach. Quality of life (WHOQoL-BREF), perceived social support (DUKE-UNC-11), and treatment adherence (MMAS-8) among MMP users were studied, and data on sociodemographic and clinical characteristics were collected through ad hoc questionnaires and a review of electronic medical records. Linear and logistic regression models were used. Results: A total of 70 individuals were included in this study. The mean age was 56.9 years, and 83% of the participants were male. The perceived quality of life was low in the four domains evaluated (range of 47.4–48.2). A total of 38.57% of the participants had low perceived social support. Treatment adherence was low or moderate in 77.1% of the participants. Greater perceived social support was associated with better quality of life in all domains (p < 0.05). Quality of social life was negatively associated with the use of nonbenzodiazepine neuroleptics and HIV status. Treatment adherence was lower in insulin therapy users. Conclusions: Social support is a key determinant of the quality of life of MMP users. Health policies should promote social support networks as a strategy to improve the well-being of this population. Full article

Background/Objectives: Opioid use disorder (OUD) remains a severe health problem globally, resulting in substantial social and economic challenges. While existing medications for managing OUD are proven to be effective, they also present certain challenges. A vaccine offers a promising therapeutic strategy to combat OUD and potentially reduce the risk of overdose death. The TT-6-AmHap heroin conjugate vaccine has effectively reduced heroin-induced pharmacological effects in behavioral assays as well as demonstrated the induction of high titer and high affinity antibody responses in mice and rats. In this GLP study conducted in rabbits, the potential local and systemic toxicity of the TT-6-AmHap heroin vaccine in combination with or without adjuvants ALF43 and Alhydrogel^® (ALFA) was investigated. Methods: Male and female New Zealand White rabbits were administered with vaccines or a saline control intramuscularly at two-week intervals over a 57-day study period. The presence, persistence or reversibility of any toxic effects of the vaccine was determined over a four-week recovery period. Results: Administration of TT-6-AmHap with or without the adjuvants induced high antibody-specific IgG in treatment groups compared to the controls. The study found no TT-6-AmHap-related effects on mortality, physical examinations, dermal Draize observations, body weights, body weight changes, food consumption, ophthalmology, clinical pathology (hematology, coagulation, clinical chemistry, and urinalysis), macroscopic pathology, or organ weights. Conclusions: Under the conditions of this study, these results demonstrate that the TT-6-AmHap vaccine with or without adjuvants was well tolerated, immunogenic, and the effects were not considered adverse in both male and female rabbits. Full article

Opioids are among the most effective drugs for treating moderate to severe pain. Unfortunately, opioid use, even short-term, can lead to addiction, tolerance, overdose, and respiratory depression. Therefore, efforts to design and develop novel compounds that would retain analgesic activity while reducing side effects continue unabated. The present study was designed to investigate the respiratory and cardiovascular effects of the hybrid peptide LENART01, which has evidenced potent antinociceptive and antimicrobial activity. This hybrid peptide, composed of N-terminally located dermorphin and C-terminal modified ranatensin pharmacophore, was tested in vivo in anesthetized rats. The main effect of LENART01 was apnea in 70% of examined animals, sighing, and a significant increase in blood pressure. Interestingly, the hybrid induced sighs less frequently than ranatensin, and apnea dependent on vagus nerve mu opioid receptor activation much less frequently and less intensely than dermorphin itself. This shows that LENART01 is a safer opioid system-related agent as compared to dermorphin for its prospective use in the treatment of pain. Full article

Postoperative ileus is a prolonged impairment of gastrointestinal motility following surgical procedures. This often leads to increased morbidity, extended hospital stays, and high healthcare expenditures. In this review, we discuss the pathophysiology underlying postoperative ileus, its epidemiology, and perioperative management strategies. Patient characteristics, as well as expected perioperative course, could be used to stratify the risks of postoperative ileus. Preventive measures hinge upon a multimodal approach, minimally invasive surgical techniques, fluid management, early postoperative ambulation, and opioid-sparing analgesia strategies. Adjuvant interventions such as alvimopan, caffeine, and chewing gum have demonstrated efficacy in modulating the neurogenic and inflammatory components of postoperative ileus. Minimally invasive approaches, comprehensive perioperative management, and adjuvant therapies hold promise for prevention. Current management relies heavily on supportive care, underscoring the need for research into the underlying neurogenic and inflammatory mechanisms to guide the development of targeted treatments. Full article

Opioid use disorder (OUD) is a chronic disease that remains difficult to treat, even with significant improvements in available medications. While current treatments work well for some, they often do not account for the unique needs of individual patients, leading to less-than-ideal results. Precision medicine offers a new path forward by tailoring treatments to fit each person’s genetic, psychological, and social needs. This review takes a close look at medications for OUD, including methadone, buprenorphine, and naltrexone, as well as long-acting options that may improve adherence and convenience. Beyond medications, the review highlights the importance of addressing mental health co-morbidities, trauma histories, and social factors like housing or support systems to create personalized care plans. The review also explores how emerging technologies, including artificial intelligence and digital health tools, can enhance how care is delivered. By identifying research gaps and challenges in implementing precision medicine into practice, this review emphasizes the potential to transform OUD treatment. A more individualized approach could improve outcomes, reduce relapse, and establish a new standard of care focused on recovery and patient well-being. Full article

Background: The endogenous opioid system plays a pivotal role in numerous physiological processes and is implicated in a range of diseases, including atherosclerosis, a condition contributing to nearly 50% of deaths in Western societies. Objectives: This study investigates the effects of opioid receptor blockade, using naloxone, on the plasma lipid profile and atherosclerosis progression. Methods: ApoE^−/− mice with advanced atherosclerosis were treated with naloxone for seven days, and the effects on atherosclerotic plaque development and liver steatosis were evaluated. Results: A proteomic analysis of liver samples post-treatment identified 38 proteins with altered abundance. The results revealed that naloxone treatment led to an increase in HDL cholesterol, a lipid fraction associated with protective cardiovascular effects. Furthermore, naloxone did not influence the progression of atherosclerotic plaques or the development of liver steatosis. Conclusions: In conclusion, while short-term naloxone treatment in mice with advanced atherosclerosis does not alter overall atherosclerotic plaque progression or liver steatosis, the observed elevation in HDL cholesterol and the extensive changes in liver protein abundance underscore the complex and multifaceted role of the opioid system in lipid metabolism and cardiovascular health. These findings provide a foundation for further exploration of opioid receptor antagonists as modulators of lipid profiles and potential contributors to cardiovascular therapy. Full article

Background/Objective: Fentanyl plays a pivotal role in the opioid epidemic, defined by four waves of overdose deaths. To analyse fentanyl research trends, examining its links to mental health, pharmaceutical development, healthcare, diseases, and pathophysiology within the broader social and health context of the time. Methods: To understand the evolution of scientific publications on fentanyl and its relationship to the opioid crisis, a search using Web of Science Core Collection and PubMed was conducted. A total of 53,670 documents were retrieved related to opioid scientific production, among which 1423 articles (3%) focused specifically on fentanyl. The 21,546 MeSH terms identified in these documents were analysed by publication year and specific fields: Psychiatry and Psychology, Chemicals and Drugs, Healthcare, Diseases, and Phenomena and Processes. R-statistical/FactoMineR libraries were used for the correspondence analysis. Results: In the first overdose death wave, research focused on improving therapies and reducing side effects. The second wave emphasised detoxification methods with naltrexone, methadone, and behavioural therapies. The third wave addressed psychological treatments and HIV-syringe-sharing prevention. The fourth wave prioritised less addictive analogues and understanding consumer profiles to combat the epidemic. Conclusions: Fentanyl research has evolved alongside real-world challenges, reinforcing the connection between patients’ needs, healthcare professionals’ roles, illicit users, policymakers, and the research community’s contributions to addressing both therapeutic use and its broader societal impact. These findings highlight the necessity for an interdisciplinary approach to scientific research integrating prevention, treatment, education, legal reform, and social support, emphasising the need for public health policies and collaborative research to mitigate its impact. Full article

Background and clinical significance: Acute reduction in vigilance is a frequent reason for emergency department admissions, especially among the elderly. While intracranial causes or infections with fluid depletion are often responsible, there remain cases where imaging, laboratory tests, and clinical examination fail to provide a clear diagnosis. Case presentation: A 91-year-old woman was presented to the emergency department with recurrent episodes of somnolence to deep coma. On admission, her vital signs were stable, and cerebral CT imaging revealed no intracranial pathology. Laboratory analyses, including blood gas measurements, were unremarkable. Empirical treatment for possible intoxications with benzodiazepines or opioids using flumazenil and naloxone had no effect. An Addison’s crisis was considered but excluded following methylprednisolone administration without improvement in consciousness. Eventually, an isolated elevation of serum ammonia was identified as the cause of the reduced vigilance. Further investigation linked the hyperammonemia to abnormal intestinal bacterial colonization, likely due to a prior ureteroenterostomy. There was no evidence of liver dysfunction, thus classifying the condition as non-hepatic hyperammonemia. Therapy was initiated with rifaximin, supported by aggressive laxative regimens. Ammonia levels and vital parameters were closely monitored. The patient’s condition improved gradually, with serum ammonia levels returning to normal and cognitive function fully restored. Conclusions: This case highlights an uncommon cause of coma due to non-hepatic hyperammonemia in the absence of liver disease, emphasizing the diagnostic challenge when standard evaluations are inconclusive. It underscores the need for broad differential thinking in emergency settings and the importance of considering rare metabolic disturbances as potential causes of altered mental status. Full article

Canada’s national surveillance shows an 11% year-over-year decline in deaths from opioid and other unregulated drug poisonings, and a 10% drop in related hospitalisations in 2024. In stark contrast, Québec, home to more than nine million residents, and Montréal, the country’s second-largest city, experienced a continued rise in suspected drug-poisoning mortality through 2024, with fentanyl or analogues detected in almost two-thirds of opioid deaths. We conducted a narrative synthesis of provincial coroner and public-health surveillance tables, Health Canada dashboards, and the 2022–2025 Québec Strategy on Psychoactive-Substance Overdose Prevention. Results indicate a 40% increase in opioid-related mortality since 2018, a parallel uptick in stimulant toxicity, and a five-fold rise in overdose reversals at Montréal supervised-consumption services during the COVID-19 pandemic recovery. We aim to summarise the key problems underlying this epidemic and offer province-specific public-health strategies while also sending a call to action for first-line clinicians and psychiatrists to integrate overdose-risk screening, take-home naloxone, and stimulant-use-disorder treatments into routine care. We further urge Québec healthcare professionals to deepen their knowledge of provincial services such as supervised-injection sites and stay up to date with the rapidly evolving substance-use-prevention literature. Québec’s divergent trajectory underscores the need for region-tailored harm-reduction investments and stronger policy-to-clinic feedback loops to reduce preventable deaths. Full article

Medetomidine, a veterinary α2-adrenergic agonist, has recently emerged as an adulterant in the non-medical opioid supply, yet human exposure has remained poorly characterized. We conducted a pragmatic retrospective cohort analysis utilizing chart review and liquid chromatography–tandem mass spectrometry (LC-MS/MS) toxicology testing on available urine samples from patients presenting to two hospitals in Philadelphia, PA, who fit two clinical phenotypes, intoxication or withdrawal. Samples also underwent glucuronidase pre-treatment to assess impact on the yield of medetomidine and xylazine metabolite detection. Testing identified universal exposure to medetomidine (58/58 samples) via the 3-hydroxy-medetomidine (3-OH-M) metabolite, post glucuronidase treatment and variable xylazine exposure (40/58 samples). Importantly, 32% of medetomidine exposures would have been missed without enzymatic pre-treatment. Patients exhibited two distinct clinical phenotypes: intoxication, characterized primarily by sedation; bradycardia; and often hypotension, and withdrawal, presenting with life-threatening tachycardia; hypertension and often encephalopathy. Notably, clinical phenotype correlated with urinary concentrations of 3-OH-M but not xylazine. These findings underscore the critical need for heightened clinical awareness and need for contemporaneous toxicologic screening mechanisms for medetomidine exposure, emphasizing its distinct clinical presentations and the potential public health implications posed by its widespread adulteration in illicit opioids. Full article