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Pharmaceuticals (Basel, Switzerland) Jun 2023Opioids are considered the cornerstone of pain management: they show good efficacy as a first-line therapy for moderate to severe cancer pain. Since...
BACKGROUND
Opioids are considered the cornerstone of pain management: they show good efficacy as a first-line therapy for moderate to severe cancer pain. Since pharmacokinetic/pharmacodynamic information about the tissue-specific effect and toxicity of opioids is still scarce, their quantification in post-mortem autoptic specimens could give interesting insights.
METHODS
We describe an ultra-high-performance liquid chromatography coupled with tandem mass spectrometry method for the simultaneous quantification of methadone, morphine, oxycodone, hydrocodone, oxymorphone, hydromorphone and fentanyl in several tissues: liver, brain, kidney, abdominal adipose tissue, lung and blood plasma. The presented method has been applied on 28 autoptic samples from different organs obtained from four deceased PLWH who used opioids for palliative care during terminal disease.
RESULTS
Sample preparation was based on tissue weighing, disruption, sonication with drug extraction medium and a protein precipitation protocol. The extracts were then dried, reconstituted and injected onto the LX50 QSight 220 (Perkin Elmer, Milan, Italy) system. Separation was obtained by a 7 min gradient run at 40 °C with a Kinetex Biphenyl 2.6 µm, 2.1 × 100 mm. Concerning the analyzed samples, higher opioids concentrations were observed in tissues than in plasma. Particularly, O-MOR and O-COD showed higher concentrations in kidney and liver than other tissues (>15-20 times greater) and blood plasma (>100 times greater).
CONCLUSIONS
Results in terms of linearity, accuracy, precision, recovery and matrix effect fitted the recommendations of FDA and EMA guidelines, and the sensitivity was high enough to allow successful application on human autoptic specimens from an ethically approved clinical study, confirming its eligibility for post-mortem pharmacological/toxicological studies.
PubMed: 37375850
DOI: 10.3390/ph16060903 -
Neuropharmacology Oct 2023Over the past two decades, the escalating prescription of opioid medications for pain management has culminated in a widespread opioid epidemic, significantly impacting...
Over the past two decades, the escalating prescription of opioid medications for pain management has culminated in a widespread opioid epidemic, significantly impacting public health, social dynamics, and economic stability. The urgent need for improved treatments for opioid addiction necessitates a deeper understanding of its biological underpinnings, with genetic variations playing a crucial role in individual susceptibility to opioid use disorder (OUD) and influencing clinical practices. In this study, we leverage the genetic diversity of four rat strains (ACI/N, BN/NHsd, WKY/N, and F344/N) to examine the contribution of genetic factors to oxycodone metabolism and addiction-like behaviors. We used the extended access to intravenous oxycodone self-administration procedure (12 h/day, 0.15 mg/kg/injection) to comprehensively characterize oxycodone-related behaviors and pharmacokinetics. We measured escalation of oxycodone self-administration, motivation for drug consumption, tolerance to the analgesic effects of oxycodone, withdrawal-induced hyperalgesia, and oxycodone-induced respiratory depression. Additionally, we examined oxycodone-seeking behavior after four weeks of withdrawal by reintroducing the animals to environmental and cue stimuli previously associated with oxycodone self-administration. The findings revealed notable strain differences in several behavioral measures, including oxycodone metabolism. Intriguingly, BN/NHsd and WKY/N strains exhibited similar drug intake and escalation patterns but displayed significant disparities in oxycodone and oxymorphone metabolism. Minimal sex differences were observed within strains, primarily relating to oxycodone metabolism. In conclusion, this study identifies strain differences in the behavioral responses and pharmacokinetics associated with oxycodone self-administration in rats, providing a robust foundation for identifying genetic and molecular variants associated with various facets of the opioid addiction process.
Topics: Rats; Female; Male; Animals; Oxycodone; Rats, Inbred ACI; Rats, Inbred F344; Rats, Inbred WKY; Analgesics, Opioid; Opioid-Related Disorders; Self Administration
PubMed: 37327971
DOI: 10.1016/j.neuropharm.2023.109635 -
Biological Psychiatry Dec 2023Mu opioid receptors (MORs) are key for reward processing, mostly studied in dopaminergic pathways. MORs are also expressed in the dorsal raphe nucleus (DRN), which is...
BACKGROUND
Mu opioid receptors (MORs) are key for reward processing, mostly studied in dopaminergic pathways. MORs are also expressed in the dorsal raphe nucleus (DRN), which is central for the modulation of reward and mood, but MOR function in the DRN remains underexplored. Here, we investigated whether MOR-expressing neurons of the DRN (DRN-MOR neurons) participate in reward and emotional responses.
METHODS
We characterized DRN-MOR neurons anatomically using immunohistochemistry and functionally using fiber photometry in responses to morphine and rewarding/aversive stimuli. We tested the effect of opioid uncaging on the DRN on place conditioning. We examined the effect of DRN-MOR neuron optostimulation on positive reinforcement and mood-related behaviors. We mapped their projections and selected DRN-MOR neurons projecting to the lateral hypothalamus for a similar optogenetic experimentation.
RESULTS
DRN-MOR neurons form a heterogeneous neuronal population essentially composed of GABAergic (gamma-aminobutyric acidergic) and glutamatergic neurons. Calcium activity of DRN-MOR neurons was inhibited by rewarding stimuli and morphine. Local photo-uncaging of oxymorphone in the DRN produced conditioned place preference. DRN-MOR neuron optostimulation triggered real-time place preference and was self-administered, promoted social preference, and reduced anxiety and passive coping. Finally, specific optostimulation of DRN-MOR neurons projecting to the lateral hypothalamus recapitulated the reinforcing effects of total DRN-MOR neuron stimulation.
CONCLUSIONS
Our data show that DRN-MOR neurons respond to rewarding stimuli and that their optoactivation has reinforcing effects and promotes positive emotional responses, an activity which is partially mediated by their projections to the lateral hypothalamus. Our study also suggests a complex regulation of DRN activity by MOR opioids, involving mixed inhibition/activation mechanisms that fine-tune DRN function.
Topics: Dorsal Raphe Nucleus; Receptors, Opioid, mu; Neurons; Morphine; Analgesics, Opioid; Reward
PubMed: 37285896
DOI: 10.1016/j.biopsych.2023.05.019 -
Clinical Pharmacokinetics Jul 2023Up to 90% of patients with castration-resistant prostate cancer (CRPC) will develop symptomatic bone metastases requiring pain medication, with opioids being the...
BACKGROUND AND OBJECTIVE
Up to 90% of patients with castration-resistant prostate cancer (CRPC) will develop symptomatic bone metastases requiring pain medication, with opioids being the mainstay of therapy in treating moderate and severe pain. Enzalutamide is an androgen receptor antagonist for the treatment of CRPC and a strong inducer of cytochrome P450 (CYP)3A4. Hereby, enzalutamide potentially reduces the exposure of oxycodone, an opioid metabolized by CYP3A4 and CYP2D6. Our objective was to evaluate the potential drug-drug interaction of enzalutamide and oxycodone.
METHODS
A prospective, nonrandomized, open-label, two-arm parallel study was performed. All patients received a single dose of 15 mg normal-release oxycodone. Patients in the enzalutamide arm (ENZ-arm) received enzalutamide 160 mg once daily. Plasma concentrations of oxycodone and its metabolites were quantified using a validated liquid chromatography with tandem mass spectrometry (LC-MS/MS) method.
RESULTS
Twenty-six patients (13 ENZ-arm; 13 control arm) were enrolled in the study. Enzalutamide decreased the mean AUC and C of oxycodone with, respectively, 44.7% (p < 0.001) and 35.5% (p = 0.004) compared with the control arm. The AUC and C of the active metabolite oxymorphone were 74.2% (p < 0.001) and 56.0% (p = 0.001) lower in the ENZ-arm compared with the control arm. In contrast, AUC and C of the inactive metabolites noroxycodone and noroxymorphone were significantly increased by enzalutamide.
CONCLUSION
Co-administration of enzalutamide significantly reduced exposure to oxycodone and its active metabolite oxymorphone in men with prostate cancer. This should be taken into account when prescribing enzalutamide combined with oxycodone.
Topics: Male; Humans; Oxycodone; Oxymorphone; Chromatography, Liquid; Prospective Studies; Prostatic Neoplasms, Castration-Resistant; Tandem Mass Spectrometry; Analgesics, Opioid; Pain
PubMed: 37162620
DOI: 10.1007/s40262-023-01255-1 -
Foods (Basel, Switzerland) Apr 2023The increase in bacterial resistance and the decline in the effectiveness of antimicrobial agents are challenging issues for the control of infectious diseases....
The increase in bacterial resistance and the decline in the effectiveness of antimicrobial agents are challenging issues for the control of infectious diseases. Traditional Chinese herbal plants are potential sources of new or alternative medicine. Here, we identified antimicrobial components and action modes of the methanol-phase extract from an edible herb Wight et Arn, which had a 68.18% inhibition rate against 22 species of common pathogenic bacteria. The extract was purified using preparative high-performance liquid chromatography (Prep-HPLC), and three separated fragments (Fragments 1-3) were obtained. Fragment 1 significantly elevated cell surface hydrophobicity and membrane permeability but reduced membrane fluidity, disrupting the cell integrity of the Gram-negative and Gram-positive pathogens tested ( < 0.05). Sixty-six compounds in Fragment 1 were identified using Ultra-HPLC and mass spectrometry (UHPLC-MS). The identified oxymorphone (6.29%) and rutin (6.29%) were predominant in Fragment 1. Multiple cellular metabolic pathways were altered by Fragment 1, such as the repressed ABC transporters, protein translation, and energy supply in two representative Gram-negative and Gram-positive strains ( < 0.05). Overall, this study demonstrates that Fragment 1 from Wight et Arn is a promising candidate for antibacterial medicine and food preservatives.
PubMed: 37107435
DOI: 10.3390/foods12081640 -
Frontiers in Pharmacology 2023The United States (US) ranks high, nationally, in opioid consumption. The ongoing increase in the misuse and mortality amid the opioid epidemic has been contributing to...
The United States (US) ranks high, nationally, in opioid consumption. The ongoing increase in the misuse and mortality amid the opioid epidemic has been contributing to its rising cost. The worsening health and economic impact of opioid use disorder in the US warrants further attention. We, therefore, assessed commonly prescribed opioids to determine the opioids that were over-represented versus under-represented for adverse drug events (ADEs) to better understand their distribution patterns using the Food and Drug Administration's Adverse Event Reporting System (FAERS) while correcting for distribution using the Drug Enforcement Administration's Automation of Reports and Consolidated Orders System (ARCOS). Comparing the ratio of the percentage of adverse drug events as reported by the FAERS relative to the percentage of distribution as reported by the ARCOS database is a novel approach to evaluate post-marketing safety surveillance and may inform healthcare policies and providers to better regulate the use of these opioids. We analyzed the adverse events for 11 prescription opioids, when correcting for distribution, and their ratios for three periods, 2006-2010, 2011-2016, and 2017-2021, in the US. The opioids include buprenorphine, codeine, fentanyl, hydrocodone, hydromorphone, meperidine, methadone, morphine, oxycodone, oxymorphone, and tapentadol. Oral morphine milligram equivalents (MMEs) were calculated by conversions relative to morphine. The relative ADEs of the selected opioids, opioid distributions, and ADEs relative to distribution ratios were analyzed for the 11 opioids. Oxycodone, fentanyl, and morphine accounted for over half of the total number of ADEs ( = 667,969), while meperidine accounted for less than 1%. Opioid distributions were relatively constant over time, with methadone repeatedly accounting for the largest proportions. Many ADE-to-opioid distribution ratios increased over time, with meperidine (60.6), oxymorphone (11.1), tapentadol (10.3), and hydromorphone (7.9) being the most over-represented for ADEs in the most recent period. Methadone was under-represented (<0.20) in all the three periods. The use of the FAERS with the ARCOS provides insights into dynamic changes in ADEs of the selected opioids in the US. There is further need to monitor and address the ADEs of these drugs.
PubMed: 37033633
DOI: 10.3389/fphar.2023.1163976 -
Clinical Drug Investigation Mar 2023While the current landscape of opioid use disorder (OUD) is complicated by the increase in use of non-prescription opioids, prescription opioids continue to be...
BACKGROUND AND OBJECTIVE
While the current landscape of opioid use disorder (OUD) is complicated by the increase in use of non-prescription opioids, prescription opioids continue to be frequently used in non-medical ways. In response to this abuse, pharmaceutical companies have developed abuse deterrent formulations (ADFs) for extended-release (ER) opioids. To test the effectiveness of Xtampza ER ADF (oxycodone myristate) at reducing tampering, its rate of tampering in a treatment-center population was compared to immediate release (IR) single entity (SE) oxycodone, other ER oxycodone opioids, and ER oxymorphone.
METHODS
Data were collected between the third quarter of 2018 and the third quarter of 2021 from individuals entering nationally distributed opioid treatment programs. To determine odds of tampering with Xtampza ER compared to each comparator, a logistic model was fit with a random intercept allowing for multiple drugs in each subject. Within-subject correlation was assumed to have a compound symmetric relationship.
RESULTS
Overlap among the categories of drug tampering was high. Logistic regression analyses found that oxycodone myristate had lower odds of tampering when compared to both IR SE oxycodone (OR = 0.23 [95% CI 0.11, 0.50], p = 0.0002) and ER oxymorphone (OR = 0.30 [95% CI 0.14, 0.67], p = 0.0038). Oxycodone myristate was not significantly different from other ER oxycodone opioids (OR = 0.5 [95% CI 0.24, 1.03], p = 0.0612). These findings did not change when the estimates were adjusted for age and sex.
CONCLUSIONS
Drugs employing ADF technology may reduce the likelihood of tampering when compared to non-ADF formulations in a treatment-center population, which represents an opportunity for intervention in OUD among those still requiring pain management.
Topics: Humans; Analgesics, Opioid; Oxycodone; Abuse-Deterrent Formulations; Cross-Sectional Studies; Oxymorphone; Opioid-Related Disorders; Delayed-Action Preparations
PubMed: 36859697
DOI: 10.1007/s40261-023-01248-9 -
BioRxiv : the Preprint Server For... Feb 2023Traditional methods for site-specific drug delivery in the brain are slow, invasive, and difficult to interface with recordings of neural activity. Here, we demonstrate...
UNLABELLED
Traditional methods for site-specific drug delivery in the brain are slow, invasive, and difficult to interface with recordings of neural activity. Here, we demonstrate the feasibility and experimental advantages of photopharmacology using "caged" opioid drugs that are activated in the brain with light after systemic administration in an inactive form. To enable bidirectional manipulations of endogenous opioid receptors , we developed PhOX and PhNX, photoactivatable variants of the mu opioid receptor agonist oxymorphone and the antagonist naloxone. Photoactivation of PhOX in multiple brain areas produced local changes in receptor occupancy, brain metabolic activity, neuronal calcium activity, neurochemical signaling, and multiple pain- and reward-related behaviors. Combining PhOX photoactivation with optical recording of extracellular dopamine revealed adaptations in the opioid sensitivity of mesolimbic dopamine circuitry during chronic morphine administration. This work establishes a general experimental framework for using photopharmacology to study the neural basis of drug action.
HIGHLIGHTS
A photoactivatable opioid agonist (PhOX) and antagonist (PhNX) for photopharmacology. Systemic pro-drug delivery followed by local photoactivation in the brain. photopharmacology produces behavioral changes within seconds of photostimulation. photopharmacology enables all-optical pharmacology and physiology.
PubMed: 36778286
DOI: 10.1101/2023.02.02.526901 -
Annals of Translational Medicine Dec 2022Oxycodone is a commonly used oral opioid in children for treating postoperative pain. Highly polymorphic gene metabolizes oxycodone into its more potent metabolite,...
BACKGROUND
Oxycodone is a commonly used oral opioid in children for treating postoperative pain. Highly polymorphic gene metabolizes oxycodone into its more potent metabolite, oxymorphone. We hypothesized that altered activity due to polymorphisms will influence oxycodone requirements {relative oxycodone use [oxycodone morphine equivalents (MEq)/total MEq] to maintain analgesia} (primary outcome) and risk for oxycodone induced side-effects such as respiratory depression (RD) and emesis (secondary outcomes). We also explored the influence of genotype availability and provider guidance on oral opioid prescription patterns.
METHODS
Patients who underwent Nuss procedure and spine fusion with genotyping results available preoperatively were included. Data on demographics, genotypes, oral opioids, pain scores, RD and emesis were collected. Univariate and multivariable regression for comparison of genotype predicted poor, ultrarapid, intermediate metabolizers (PM, UM and IM) phenotype with normal metabolizers (NM) for outcomes were performed. Stratified logistic regression was conducted in low (oxycodone/total MEq <0.5) and high (and oxycodone/total MEq >0.5) oxycodone use groups for RD and emesis, with application of firth correction due to quasi-complete separations. Breslow-Day test was used to evaluate odds ratios for prescribing genotype directed opioid between control group (2012-15) (where providers were alerted to genotyping results availability but not directed to use them while prescribing) and genotype directed groups (2016-18) (where providers were directed to use the genotyping results available to them while prescribing oxycodone after surgery).
RESULTS
Of 193 subjects (age 15.9±0.25 years, 28.5% female, 93.78% White; 101 NM, 76 IM, 10 PM and 6 UM), 77.72% underwent pectus surgery. phenotype was associated with oxycodone MEq/total MEq requirements (P<0.001). Both PM and UM phenotypes had lower oxycodone requirements compared to NM [-0.316 (SE 0.098), P=0.005 and -0.432 (SE 0.113), P<0.001 respectively]. phenotype was associated with RD in high use oxycodone group (P=0.018) but not low use oxycodone groups (P=0.634). No phenotype association was found for emesis. Oxycodone was prescribed to 91.24% of NM/IM 66.67% of PM/UM (P=0.129) in control group and 94.64% of NM/IM 28.57% of PM/UM (P<0.001) in the genotype-directed group. PM/UM phenotypes in genotype directed group had a lower chance of being prescribed oxycodone (effect size =-2.775; SE 1.566; P=0.076).
CONCLUSIONS
Our findings suggest genotypes are associated with oxycodone requirements for analgesia and may influence risk for RD. Genotype availability and guidance likely influence oral opioid prescription pattern after surgery. Our findings are limited by small sample size for UM/PM groups.
PubMed: 36618804
DOI: 10.21037/atm-2022-58 -
The Medical Letter on Drugs and... Dec 2022
Topics: Humans; Analgesics, Opioid; Codeine; Administration, Cutaneous; Oxycodone; Morphine
PubMed: 36541939
DOI: No ID Found