Effect of repeated intraperitoneal injections of different concentrations of oxycodone on immune function in mice.

Background: The effect of oxycodone as an opioid receptor agonist on immune function is still controversial. In this study, we investigated the possible effects of oxycodone on immune function in mice and its possible mechanisms of action. Methods: By repeated intraperitoneal injections of 25 mg/kg morphine and 5 mg/kg, 20 mg/kg, and 60 mg/kg oxycodone, we assessed possible changes in the number of splenic lymphocytes and inflammatory cytokines in the serum of mice. CD4+ T cells and CD8+ T cells were sorted from the spleen to observe whether the expression levels of opioid receptors and downstream signals were altered. Results: Repeated administration of oxycodone at a dose above 20 mg/kg resulted in significant weight loss. Repeated administration of oxycodone exhibits significant dose-dependent reduction in CD4+ T cells, with little effect on CD8+ T cells and little effect on inflammatory cytokine levels. Low- and intermediate-dose oxycodone increased the mRNA expression level of MOR, KOR, and DOR to varying degrees. Moreover, oxycodone increases the mRNA expression levels of the TLR4 signaling pathway to varying degrees. Conclusion: Repeated intraperitoneal injection of oxycodone induces immunosuppression in mice.

Comparing the effects of pre-emptive oxycodone, diclofenac, and gabapentin on postoperative pain after tibia fracture surgery: A randomized clinical trail.

Background: Postoperative pain (POP) is one of the most common and most important types of pain. Objectives: The aim of this study was to compare the effects of pre-emptive oxycodone, diclofenac, and gabapentin on postoperative pain (POP) among patients with tibia fracture surgery. Materials and Methods: This double-blind three-group randomised controlled trial was conducted in 2023. Participants were 111 candidates for tibia fracture surgery under general anaesthesia. They were randomly allocated to oxycodone, gabapentin, and diclofenac groups through block randomisation. Baseline arterial oxygen saturation, heart rate, and blood pressure were documented before surgery and POP and sedation status were measured during postoperative recovery and 2, 4, 6, 12, and 24 h after surgery. Postoperative opioid analgesic use was also documented. The data were analysed using the SPSS software (v. 20.0) at a significance level of less than 0.05. Results: Groups did not significantly differ from each other respecting participants' baseline age, gender, body mass index, arterial oxygen saturation, heart rate, blood pressure, and surgery duration (P > 0.05). Moreover, there were no significant differences among the groups respecting POP and sedation status at different measurement time points (P > 0.05), except for six hours after surgery at which the POP mean score in the gabapentin group was significantly less than the other two groups (P = 0.001). Among-group differences respecting postoperative use of opioid analgesics and medication side effects were also insignificant (P > 0.05). Conclusion: Pre-emptive oxycodone, diclofenac, and gabapentin significantly reduce POP among patients with tibia fracture surgery, though gabapentin may produce more significant analgesic effects. All these three medications can be used for pre-emptive analgesia. Of course, the best pre-emptive analgesic agent is determined based on the opinion of the treating physician.

Opioid-Based Haptens: Development of Immunotherapy.

Over the past decades, extensive preclinical research has been conducted to develop vaccinations to protect against substance use disorder caused by opioids, nicotine, cocaine, and designer drugs. Morphine or fentanyl derivatives are small molecules, and these compounds are not immunogenic, but when conjugated as haptens to a carrier protein will elicit the production of antibodies capable of reacting specifically with the unconjugated hapten or its parent compound. The position of the attachment in opioid haptens to the carrier protein will influence the specificity of the antiserum produced in immunized animals with the hapten-carrier conjugate. Immunoassays for the determination of opioid drugs are based on the ability of drugs to inhibit the reaction between drug-specific antibodies and the corresponding drug-carrier conjugate or the corresponding labelled hapten. Pharmacological studies of the hapten-carrier conjugates resulted in the development of vaccines for treating opioid use disorders (OUDs). Immunotherapy for opioid addiction includes the induction of anti-drug vaccines which are composed of a hapten, a carrier protein, and adjuvants. In this review we survey the design of opioid haptens, the development of the opioid radioimmunoassay, and the results of immunotherapy for OUDs.

Electrochemical sensor based on mesoporous g-C3N4/N-CNO/gold nanoparticles for measuring oxycodone.

Oxycodone, often used as an analgesic, is a potent opioid. While its effectiveness has been proven in the control of moderate to acute pain, excessive use of oxycodone imposes heart failure, heart palpitations, reduction of red blood cells, bone pain, and even death. Therefore, monitoring the oxycodone concentration in blood is vital for emergency care. For this purpose, a novel electrochemical sensor was designed based on a glassy carbon electrode modified with mesoporous g-C3N4 (M-C3N4), carbon nano-onions doped with nitrogen (N-CNO), and gold nanoparticles. At first, the SEM and XRD techniques were employed to characterize prepared M-C3N4 and N-CNO samples. The electro-oxidation behavior of the oxycodone was evaluated by cyclic and differential pulse voltammetric methods. Based on the influence of the potential scanning rate and solution pH on the voltammetric response of oxycodone oxidation, a redox mechanism was proposed. A 16 nM detection limit was acquired for the oxycodone analysis with a linear response in the 0.05-150 µM range. This sensor showed a remarkable ability for oxycodone detection in plasma samples. The long-term stability, superior selectivity, and reproducibility of this sensor prove its ability to measure oxycodone accurately and precisely in authentic spices.

METTL14-mediated upregulation of lncRNA HOTAIR represses PP1α expression by promoting H3K4me1 demethylation in oxycodone-treated mice.

N6-methyladenosine (m6A) methylation is a vital epigenetic mechanism associated with drug addiction. However, the relationship between m6A modification and oxycodone rewarding is less well explored. Based on an open field test, the present study evaluated oxycodone rewarding using chromatin immunoprecipitation PCR, immunofluorescence, and RNA sequencing. A marked increase in METTL14 protein and a decrease in PP1α protein due to oxycodone abundance in the striatal neurons were observed in a dose- and time-dependent manner. Oxycodone markedly increased LSD1 expression, and decreased H3K4me1 expression in the striatum. In the open field test, intra-striatal injection of METTL14 siRNA, HOTAIR siRNA, or LSD1 shRNA blocked oxycodone-induced increase in locomotor activity. The downregulation of PP1α was also inhibited after treatment with METTL14/HOTAIR siRNA and LSD1 shRNA. Enhanced binding of LSD1 with CoRest and of CoRest with the PP1α gene induced by oxycodone was also reversed by LSD1 shRNA. In addition, H3K4me1 demethylation was also blocked by the treatment. In summary, the investigation confirmed that METTL14-mediated upregulation of HOTAIR resulted in the repression of PP1α, which in turn facilitated the recruitment of LSD1, thus catalyzing H3K4me1 demethylation and promoting oxycodone addiction.

Health-Related Quality of Life in Chronic Pain Treated With Tapentadol Versus Oxycodone/Naloxone and Its Determinants: A Real-World, Single-Center Retrospective Cohort Study in Spain.

OBJECTIVES: A substantial proportion of patients with chronic noncancer pain (CNCP) are treated with tapentadol (TAP) or oxycodone/naloxone (OXN) to improve their perceived physical and mental health over time. METHODS: A cross-sectional study was conducted in 135 CNCP outpatients with usual prescribing (TAP: n = 58, OXN: n = 77) at a tertiary-care Spanish Hospital to compare health-related quality-of-life (HRQoL) records. Health utility was derived from the EQ-5D-3L. Regression models were performed to search for other HRQoL determinants. Pain intensity, relief, analgesic prescription, adverse events, inpatient stays, emergency department visits, and change to painkiller prescriptions were registered from electronic records. RESULTS: Health utility (0.43 ± 0.24 scores, from -0.654 to 1) was similar for both opioids, although TAP showed a significantly low daily opioid dose requirement, neuromodulators use, and constipation side effect compared with OXN. After multivariable adjustment, the significant predictors of impaired HRQoL were pain intensity (ß = -0.227, 95% CI -0-035 to -0.005), number of adverse events (ß = -0.201, 95% CI -0.024 to -0.004), and opioid daily dose (ß = -0.175, 95% CI -0.097 to -0.012). Male sex (ß = -0.044) and pain relief (ß = 0.158) should be taken into account for future studies. CONCLUSIONS: HRQoL was similar for TAP and OXN in real-world patients with CNCP, albeit with a TAP opioid-sparing effect. More work is needed to explore HRQoL determinants in relation to long-term opioid use in CNCP.

Oxycodone enhances antitumor effect of paclitaxel on human breast cancer SKBR3 cells in vitro.

BACKGROUND: The influences of Oxycodone (OXY) combined with Paclitaxel (PTX) on breast cancer cells are unclear. The present study aimed to examine the effects of OXY combined with PTX on the proliferation, apoptosis, and migration of human breast cancer SKBR3 cells and the underlying mechanism. METHODS: The proliferation, apoptosis and invasion of SKBR3 cells were assessed by CCK-8, colony formation assay, flowcytometric, Transwell assay and scratch assays, respectively. In addition, Western blotting was used to detect the expression of related proteins in these cells. The autophagic bodies were observed under a transmission electron microscope. RESULTS: OXY (0.25, 0.5 and 1 mM) significantly inhibited the viability, colony-forming, migration, and invasion of SKBR3 cells as compared to the control group. Furthermore, OXY (0.25, 0.5 and 1 mM) markedly induced the apoptosis of SKBR3 cells and the levels of apoptosis-related proteins. In addition, OXY (0.25, 0.5 and 1 mM) and PTX inhibited the proliferation of SKBR3 cells synergistically as compared to PTX group in vitro. Moreover, OXY (0.25, 0.5 and 1 mM) significantly elevated the PTX-induced apoptosis in SKBR3 cells via downregulating the expression of N-cadherin, Becline-1 LC3-Ⅱ, p-Akt and p-mTOR and upregulating E-cadherin expression. Compared with the control group, OXY (1 mM) treatment induced autophagy in SKBR3 cells. CONCLUSIONS: The present study indicates that OXY can enhance the antitumor effect of PTX on breast cancer in vitro. Hence, the combination of OXY with PTX may serve as a potential strategy for the treatment of breast cancer.

Oxycodone attenuates lipopolysaccharide-induced myocardial injury by inhibiting inflammation, oxidation and pyroptosis via Nrf2/HO-1 signalling pathway.

Myocardial injury and cardiovascular dysfunction are the most common complications of sepsis, and effective therapeutic candidate is still lacking. This study aims to investigate the protective effect of oxycodone in myocardial injury of lipopolysaccharide-induced sepsis and its related signalling pathways. Wild-type and nuclear factor erythroid 2-related factor 2 (Nrf2)-knockout mice, as well as H9c2 cardiomyocytes cultures treated with lipopolysaccharide (LPS) were used as models of septic myocardial injury. H9c2 cardiomyocytes culture showed that oxycodone protected cells from pyroptosis induced by LPS. Mice model confirmed that oxycodone pretreatment significantly attenuated myocardial pathological damage and improved cardiac function demonstrated by increased ejection fraction (EF) and fractional shortening (FS), as well as decreased cardiac troponin I (cTnI) and creatine kinase isoenzymes MB (CK-MB). Oxycodone also reduced the levels of inflammatory factors and oxidative stress damage induced by LPS, which involves pyroptosis-related proteins including: Nod-like receptor protein 3 (NLRP3), Caspase 1, Apoptosis-associated speck-like protein contain a CARD (ASC), and Gasdermin D (GSDMD). These changes were mediated by Nrf2 and heme oxygenase-1 (HO-1) because Nrf2-knockout mice or Nrf2 knockdown in H9c2 cells significantly reversed the beneficial effect of oxycodone on oxidative stress, inflammatory responses and NLRP3-mediated pyroptosis. Our findings yielded that oxycodone therapy reduces LPS-induced myocardial injury by suppressing NLRP3-mediated pyroptosis via the Nrf2/HO-1 signalling pathway in vivo and in vitro.

Trends in oxycodone and oxycodone-containing analgesics administration for back pain in emergency departments in the USA (2007-2018).

BACKGROUND: To describe trends in oxycodone and oxycodone-containing analgesic prescribing for the treatment of back pain among adults in emergency departments (EDs) in the USA from 2007 to 2018. METHODS: Data were gathered from the National Hospital Ambulatory Medical Care Survey (NHAMCS) from 2007 to 2018. The study population included individuals of all ages presenting to USA EDs. The NHAMCS reasons for visit and oxycodone drug ID codes were used to isolate patients with back pain. The main outcome was the proportion of oxycodone and oxycodone-containing analgesics prescribed for back pain in the EDs over the specified time period. RESULTS: There was a relative decrease in the overall administration of oxycodone for back pain in the EDs by 62.3% from 2007 (244,000 visits) to 2018 (92,000 visits). The proportion of ED patients prescribed with oxycodone-containing analgesics for back pain increased among patients aged 45 years and older (from 43.8% to 57.6%), female patients (from 54.5% to 62.0%), black patients (from 22.5% to 30.4%), and Hispanic/Latino patients (from 9.4% to 19.6%). Oxycodone/acetaminophen was most prescribed and accounted for 90.2% of all oxycodone-containing analgesics in 2007, with a decrease to 68.5% in 2018. Pure oxycodone was the second most prescribed medication, accounting for 6.1% in 2007 and 31.5% in 2018. CONCLUSION: The overall number of oxycodone-containing analgesics decreased significantly from 2007 to 2018. However, that number trended upward in 45-year-old and older, female, black, or Hispanic/Latino patients from 2007 to 2018. The total amount of pure oxycodone increased significantly from 2007 to 2008.

A proof-of-concept study of ultrasound-guided continuous parasacral ischial plane block for postoperative pain control in patients undergoing total knee arthroplasty.

BACKGROUND: Continuous peripheral nerve blocks are widely used for anesthesia and postoperative analgesia in lower limb surgeries. The authors aimed to develop a novel continuous sacral plexus block procedure for analgesia during total knee arthroplasty. METHODS: The study comprised two stages. In Stage I, the authors built upon previous theories and technological innovations to develop a novel continuous sacral plexus block method, ultrasound-guided continuous parasacral ischial plane block (UGCPIPB) and subsequently conducted a proof-of-concept study to assess its effectiveness and feasibility. Stage II involved a historical control study to compare clinical outcomes between patients undergoing this new procedure and those receiving the conventional procedure. RESULTS: The study observed a 90% success rate in catheter placement. On postoperative day (POD) 1, POD2, and POD3, the median visual analog scale (VAS) scores were 3 (range, 1.5-3.5), 2.5 (1.6-3.2), and 2.7 (1.3-3.4), respectively. Furthermore, 96.3% of the catheters remained in place until POD3, as confirmed by ultrasound. The study revealed a significant increase in skin temperature and peak systolic velocity of the anterior tibial artery on the blocked side compared with those on the non-blocked side. Complications included catheter clogging in one patient and leakage at the insertion site in two patients. In Stage II, the novel technique was found to be more successful than conventional techniques, with a lower catheter displacement rate than the conventional procedure for continuous sciatic nerve block. CONCLUSION: UGCPIPB proved to be an effective procedure and safe for analgesia in total knee arthroplasty. CHINESE CLINICAL TRIAL REGISTRY NUMBER: ChiCTR2300068902.

Effect of Oxycodone-Based Multimodal Analgesia on Visceral Pain After Major Laparoscopic Gastrointestinal Surgery: A Randomised, Double-Blind, Controlled Trial.

Purpose: Oxycodone is a potent µ- and κ-opioid receptor agonist that can relieve both somatic and visceral pain. We assessed oxycodone- vs sufentanil-based multimodal analgesia on postoperative pain following major laparoscopic gastrointestinal surgery. Methods: In this randomised double-blind controlled trial, 40 adult patients were randomised (1:1, stratified by type of surgery) to receive oxycodone- or sufentanil-based multimodal analgesia, comprising bilateral transverse abdominis plane blocks, intraoperative dexmedetomidine infusion, flurbiprofen axetil, and oxycodone- or sufentanil-based patient-controlled analgesia. The co-primary outcomes were time-weighted average (TWA) of visceral pain (defined as intra-abdominal deep and dull pain) at rest and on coughing during 0-24 h postoperatively, assessed using the numerical rating scale (0-10) with a minimal clinically important difference of 1. Results: All patients completed the study (median age, 64 years; 65% male) and had adequate postoperative pain control. The mean (SD) 24-h TWA of visceral pain at rest was 1.40 (0.77) in the oxycodone group vs 2.00 (0.98) in the sufentanil group (mean difference=-0.60, 95% CI, -1.16 to -0.03; P=0.039). Patients in the oxycodone group had a significantly lower 24-h TWA of visceral pain on coughing (2.00 [0.83] vs 2.98 [1.26]; mean difference=-0.98, 95% CI, -1.66 to -0.30; P=0.006). In the subgroup analyses, the treatment effect of oxycodone vs sufentanil on the co-primary outcomes did not differ in terms of age (18-65 years or >65 years), sex (female or male), or type of surgery (colorectal or gastric). Secondary outcomes (24-h TWA of incisional and shoulder pain, postoperative analgesic usage, rescue analgesia, adverse events, and patient satisfaction) were comparable between groups. Conclusion: For patients undergoing major laparoscopic gastrointestinal surgery, oxycodone-based multimodal analgesia reduced postoperative visceral pain in a statistically significant but not clinically important manner. Trial Registration: Chinese Clinical Trial Registry (ChiCTR2100052085).

Cannabidiol Protects against the Reinstatement of Oxycodone-Induced Conditioned Place Preference in Adolescent Male but Not Female Rats: The Role of MOR and CB1R.

Cannabidiol (CBD), a phytocannabinoid, appeared to satisfy several criteria for a safe approach to preventing drug-taking behavior, including opioids. However, most successful preclinical and clinical results come from studies in adult males. We examined whether systemic injections of CBD (10 mg/kg, i.p.) during extinction of oxycodone (OXY, 3 mg/kg, i.p.) induced conditioned place preference (CPP) could attenuate the reinstatement of CPP brought about by OXY (1.5 mg/kg, i.p.) priming in adolescent rats of both sexes, and whether this effect is sex dependent. Accordingly, a priming dose of OXY produced reinstatement of the previously extinguished CPP in males and females. In both sexes, this effect was linked to locomotor sensitization that was blunted by CBD pretreatments. However, CBD was able to prevent the reinstatement of OXY-induced CPP only in adolescent males and this outcome was associated with an increased cannabinoid 1 receptor (CB1R) and a decreased mu opioid receptor (MOR) expression in the prefrontal cortex (PFC). The reinstatement of CCP in females was associated with a decreased MOR expression, but no changes were detected in CB1R in the hippocampus (HIP). Moreover, CBD administration during extinction significantly potentialized the reduced MOR expression in the PFC of males and showed a tendency to potentiate the reduced MOR in the HIP of females. Additionally, CBD reversed OXY-induced deficits of recognition memory only in males. These results suggest that CBD could reduce reinstatement to OXY seeking after a period of abstinence in adolescent male but not female rats. However, more investigation is required.

Two Weeks of Continuous Opioid Treatment in an Adenine-Induced Mouse Model of Chronic Kidney Disease Exacerbates the Bone Inflammatory State and Increases Osteoclasts.

Patients with chronic kidney disease (CKD) report high pain levels, but reduced renal clearance eliminates many analgesic options; therefore, 30-50% of CKD patients have chronic opioid prescriptions. Opioid use in CKD is associated with higher fracture rates. Opioids may directly alter bone turnover directly through effects on bone cells and indirectly via increasing inflammation. We hypothesized that continuous opioid exposure would exacerbate the high bone turnover state of CKD and be associated with elevated measures of inflammation. Male C57Bl/6J mice after 8 weeks of adenine-induced CKD (AD) and non-AD controls (CON) had 14-day osmotic pumps (0.25-µL/hr release) containing either saline or 50-mg/mL oxycodone (OXY) surgically implanted in the subscapular region. After 2 weeks, all AD mice had elevated blood urea nitrogen, parathyroid hormone, and serum markers of bone turnover compared to controls with no effect of OXY. Immunohistochemical staining of the distal femur showed increased numbers of osteocytes positive for the mu opioid and for toll-like receptor 4 (TLR4) due to OXY. Osteocyte protein expression of tumor necrosis factor-α (TNF-α) and RANKL were higher due to both AD and OXY so that AD + OXY mice had the highest values. Trabecular osteoclast-covered surfaces were also significantly higher due to both AD and OXY, resulting in AD + OXY mice having 4.5-fold higher osteoclast-covered surfaces than untreated CON. These data demonstrate that opioids are associated with a pro-inflammatory state in osteocytes which increases the pro-resorptive state of CKD.

Neurobehavioral Characterization of Perinatal Oxycodone-Exposed Offspring in Early Adolescence.

The opioid epidemic has received considerable attention, but the impact on perinatal opioid-exposed (POE) offspring remains underexplored. This study addresses the emerging public health challenge of understanding and treating POE children. We examined two scenarios using preclinical models: offspring exposed to oxycodone (OXY) in utero (IUO) and acute postnatal OXY (PNO). We hypothesized exposure to OXY during pregnancy primes offspring for neurodevelopmental deficits and severity of deficits is dependent on timing of exposure. Notable findings include reduced head size and brain weight in offspring. Molecular analyses revealed significantly lower levels of inflammasome-specific genes in the prefrontal cortex (PFC). Gene Set Enrichment Analysis (GSEA) and Ingenuity Pathway Analysis (IPA) highlighted the enrichment of genes associated with mitochondrial and synapse dysfunction in POE offspring. Western blot analysis validated IPA predictions of mitochondrial dysfunction in PFC-derived synaptosomes. Behavioral studies identified significant social deficits in POE offspring. This study presents the first comparative analysis of acute PNO- and IUO-offspring during early adolescence finding acute PNO-offspring have considerably greater deficits. The striking difference in deficit severity in acute PNO-offspring suggests that exposure to opioids in late pregnancy pose the greatest risk for offspring well-being.

Patient-reported pain, satisfaction, adverse effects, and deviations from ambulatory surgery pain medication.

OBJECTIVES: Addressing the challenges of ambulatory surgery involves balancing effective pain relief with minimizing the side effects of pain medication. Due to the heightened risk of opioid abuse, Helsinki University Hospital (Finland) has had a stringent oxycodone prescription policy. This policy prompts an exploration into whether ambulatory surgery patients experience severe post-surgical pain and whether an increase in prescribed opioids would cause elevation in adverse effects. METHODS: This prospective cohort study, with a 1-week follow-up, included 111 adult ambulatory surgery patients (orthopaedics, urology). The patients documented their pain levels within the first postoperative week (using a numerical rating scale [NRS] of 0-10) and pain medication intake up to two days postoperatively. Furthermore, they completed a questionnaire assessing their satisfaction with pain relief, medication-related adverse effects, and adherence to instructions. Medication intake was cross-referenced with the provided instructions and prescriptions. RESULTS: A notable 56% of patients reported experiencing intense pain (NRS ≥5) within a week following surgery. Of these, 52% received a single dose of slow-release oxycodone (5-20 mg) at discharge for use on the night of surgery. Predominantly prescribed pain medications included a combination of paracetamol and codeine (64%) or ibuprofen (62%). Satisfaction rates were high, with 87% expressing satisfaction with pain medication given at hospital discharge and 90% expressing contentment with the prescribed medication. The most common adverse effects were tiredness/grogginess (45%), sleep disturbances (38%), nausea (37%), and constipation (27%). Also, 24% of patients self-reported deviations from medication instructions. A comparison of self-reported and instructed medications revealed that 14% exceeded prescribed dosages, and 28% opted for preparations different from those prescribed. Notably, patients who self-reported deviations from instructions differed from those objectively deviating from instructions. CONCLUSIONS: Although 56% of patients had intense pain, the majority expressed satisfaction with the provided pain relief. Instances of non-adherence to medication instructions were prevalent, often going unnoticed by the patients themselves.

Oxycodone or Higher Dose of Levodopa for the Treatment of Parkinsonian Central Pain: OXYDOPA Trial.

BACKGROUND: Among the different types of pain related to Parkinson's disease (PD), parkinsonian central pain (PCP) is the most disabling. OBJECTIVES: We investigated the analgesic efficacy of two therapeutic strategies (opioid with oxycodone- prolonged-release (PR) and higher dose of levodopa/benserazide) compared with placebo in patients with PCP. METHODS: OXYDOPA was a randomized, double-blind, double-dummy, placebo-controlled, multicenter parallel-group trial run at 15 centers within the French NS-Park network. PD patients with PCP (≥30 on the Visual Analogue Scale [VAS]) were randomly assigned to receive oxycodone-PR (up to 40 mg/day), levodopa/benserazide (up to 200 mg/day) or matching placebo three times a day (tid) for 8 weeks at a stable dose, in add-on to their current dopaminergic therapy. The primary endpoint was the change in average pain intensity over the previous week rated on VAS from baseline to week-10 based on modified intention-to-treat analyses. RESULTS: Between May 2016 and August 2020, 66 patients were randomized to oxycodone-PR (n = 23), levodopa/benserazide (n = 20) or placebo (n = 23). The mean change in pain intensity was -17 ± 18.5 on oxycodone-PR, -8.3 ± 11.1 on levodopa/benserazide, and -14.3 ± 18.9 in the placebo groups. The absolute difference versus placebo was -1.54 (97.5% confidence interval [CI], -17.0 to 13.90; P = 0.8) on oxycodone-PR and +7.79 (97.5% CI, -4.99 to 20.58; P = 0.2) on levodopa/benserazide. Similar proportions of patients in each group experienced all-cause adverse events. Those leading to study discontinuation were most frequently observed with oxycodone-PR (39%) than levodopa/benserazide (5%) or placebo (15%). CONCLUSIONS: The present trial failed to demonstrate the superiority of oxycodone-PR or a higher dose of levodopa in patients with PCP, while oxycodone-PR was poorly tolerated. © 2024 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

The epigenetically regulated PP1α expression by KDM1A may contribute to oxycodone conditioned place preference in mice.

The lysine-specific demethylase 1 (KDM1A) is reported to be a regulator in learning and memory. However, the effect of KDM1A in oxycodone rewarding memory has yet to be studied. In our study, rewarding memory was assessed by using conditioned place preference (CPP) in male mice. Next generation sequencing and chromatin immunoprecipitation-PCR were used to explore the molecular mechanisms. Oxycodone significantly decreased PP1α mRNA and protein levels in hippocampal neurons. Oxycodone significantly increased KDM1A and H3K4me1 levels, while significantly decreased H3K4me2 levels in a time- and dose-dependent manner. Behavioral data demonstrated that intraperitoneal injection of ORY-1001 (KDM1A inhibitor) or intra-hippocampal injection of KDM1A siRNA/shRNA blocked the acquisition and expression of oxycodone CPP and facilitated the extinction of oxycodone CPP. The decrease of PP1α was markedly blocked by the injection of ORY-1001 or KDM1A siRNA/shRNA. Oxycodone-induced enhanced binding of CoRest with KDM1A and binding of CoRest with the PP1α promoter was blocked by ORY-1001. The level of H3K4me2 demethylation was also decreased by the treatment. The results suggest that oxycodone-induced upregulation of KDM1A via demethylation of H3K4me2 promotes the binding of CoRest with the PP1α promoter, and the subsequent decrease in PP1α expression in hippocampal neurons may contribute to oxycodone reward.

Characterization and validation of a spontaneous acute and protracted oxycodone withdrawal model in male and female mice.

Opioid use disorder (OUD) is a serious health problem that may lead to physical dependence, in addition to affective disorders. Preclinical models are essential for studying the neurobiology of and developing pharmacotherapies to treat these problems. Historically, chronic morphine injections have most often been used to produce opioid-dependent animals, and withdrawal signs indicative of dependence were precipitated by administering an opioid antagonist. In the present studies, we have developed and validated a model of dependence on oxycodone (a widely prescribed opioid) during spontaneous withdrawal in male and female C57BL/6J mice. Dependence was induced by chronically administering oxycodone through osmotic minipumps at different doses for 7 days. Somatic withdrawal signs were measured after 3, 6, 24, and 48 h following minipump removal. Additionally, sensitivity to mechanical, thermal, and cold stimuli, along with anxiety-like behavior, were also measured. Our results indicated that spontaneous withdrawal following discontinuation of oxycodone produced an increase in total withdrawal signs after 60 and 120 mg/kg/day regimens of oxycodone administration. These signs were reversed by the administration of clinically approved medications for OUD. In general, both female and male mice showed similar profiles of somatic signs of spontaneous withdrawal. Spontaneous withdrawal also resulted in mechanical and cold hypersensitivity lasting for 24 and 14 days, respectively, and produced anxiety-like behaviors after 2 and 3 weeks following oxycodone removal. These results help validate a new model of oxycodone dependence, including the temporally distinct emergence of somatic, hyperalgesic, and anxiety-like behaviors, potentially useful for mechanistic and translational studies of opioid dependence.

Neuroplasticity-related genes correlate with individual differences in distinct phases of oxycodone self-administration in male rats.

Opioid use disorder (OUD) is a chronic condition associated with long-lasting molecular and behavioral changes. Animals with prolonged access to opioids develop behaviors similar to human OUD. Identifying associated molecular changes can provide insight to underpinnings that lead to or maintain OUD. In pilot studies, we identified several miRNA targets that are altered by the administration of oxycodone. We selected mir182 for follow up as it was recently shown to be dysregulated in plasma of men administered oxycodone. In addition, mir182 is increased in reward-related brain regions of male rats following exposure to various addictive substances. The present study utilizes a long-access oxycodone self-administration paradigm to examine changes in mir182 and its mRNA targets associated with neuroplasticity, which may be involved in the maintenance of OUD-like phenotype in rats. Male rats were trained to self-administer oxycodone (0.1 mg/kg/infusion, i. v.) for 6 h daily sessions for 12 days. Each animal had a yoked saline control that received matched saline infusions. Animals were then tested on a progressive ratio schedule to measure motivation to obtain a single infusion of oxycodone. Drug seeking was measured following 28 days of forced abstinence using a 90-min cued/test. RTqPCR was utilized to measure mir182 and mRNA targets related to neuroplasticity (wnt3, plppr4, pou3f3, tle4, cacna2d, and bdnf) from the nucleus accumbens. Data revealed that animals responded on a continuum for oxycodone. When divided into two groups termed high- and low responders, animals diverged during self-administration acquisition and maintained differences in behavior and gene expression throughout the study. mir182 was upregulated in the nucleus accumbens of both high and low responders and negatively correlated with tle4, which showed a strong negative correlation with reinstatement behavior. mRNA target levels were correlated with behaviors associated with increased severity of OUD behavior in male rats.

Comparison of the analgesic effects of oxycodone vs. sufentanil on postoperative pain after laparoscopic gallbladder-preserving cholecystolithotomy: a prospective randomized controlled trial.

Background: We aimed to compare the anesthesia induction effects of oxycodone and sufentanil on postoperative pain in patients undergoing laparoscopic gallbladder-preserving cholecystolithotomy, as well as changes in serum levels of inflammatory factors (TNF-α, IL-6, and IL-10) in the perioperative period. Methods: Sixty patients who underwent laparoscopic gallbladder-preserving cholecystolithotomy were evenly divided into oxycodone (O) and sufentanil (S) groups. In groups O and S, oxycodone (0.3 mg/kg) and sufentanil (0.3 ug/kg) were administered, respectively, followed by propofol (2 mg/kg) and rocuronium (0.6 mg/kg). In both groups, the intraoperative electroencephalography double-frequency index was used to guide the use of sedative and analgesic drugs, assessing the follow-up analgesic effect (VAS), degree of sedation (Ramsey), and postoperative complications at seven different time points (0, 0.5, 2, 4, 6, 8, and 24 h postoperatively). Results: Compared with the S group, patients in the O group exhibited lower VAS scores within 24 h postoperatively (P < 0.001), but there was no statistical difference between wound and shoulder pain scores (P > 0.05). Regarding postoperative awakening and extubation duration, O group patients experienced shorter times and better remedial analgesia (P < 0.05). In terms of the degree of sedation, the Ramsay score decreased at 0 h postoperatively compared with the S group (P < 0.001). Conclusion: Compared with sufentanil, oxycodone anesthesia induced better postoperative analgesia and less inflammatory responses in patients undergoing laparoscopic gallbladder-preserving cholecystolithotomy. Clinical Trial Registration: This study has been approved by the Ethics Committee of Peking University Shougang Hospital, with ethical approval (No. IRBK-2020-009), and has completed registration in the Chinese Clinical Trials Register (http://www.chictr.org.cn/) (ChiCTR2000031230).