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Expert Review of Clinical Pharmacology May 2021: Chronic low back pain (LBP) is common, and some patients require opiates therapy. This Bayesian network meta-analysis (NMA) analyzed available randomized clinical... (Meta-Analysis)
Meta-Analysis
: Chronic low back pain (LBP) is common, and some patients require opiates therapy. This Bayesian network meta-analysis (NMA) analyzed available randomized clinical trials (RCTs) on the use of opioids for LBP.: All RCTs comparing two or more opioids for chronic LBP and reporting results under the Numeric Rating Scale were included. The following drugs were analyzed: fentanyl, morphine, tapentadol, oxycodone, buprenorphine, oxymorphone, tramadol. The NMA was performed through the STATA routine for Bayesian hierarchical random-effects model analysis, with standardized mean difference (SMD) effect measure. Data regarding the rate of adverse events and different drug formulations were also reported.: Data from 2933 patients were obtained, with a mean age of 53.30 ± 6.95 years. The mean duration of symptoms prior to beginning the trial was 95.16 ± 47.29 months. The mean follow-up was 3.29 ± 1.72 months. Among the analyzed compounds, oxymorphone, tapentadol and fentanyl showed the highest efficacy in terms of pain reduction.: According to published level I evidence, oxymorphone, tapentadol and fentanyl were the most effective drugs in the treatment of chronic LBP. However, different formulation and pharmacokinetic characteristics need to be taken into consideration when choosing the ideal compound for a given patient.
Topics: Analgesics, Opioid; Bayes Theorem; Chronic Pain; Humans; Low Back Pain; Middle Aged; Network Meta-Analysis; Randomized Controlled Trials as Topic
PubMed: 33706636
DOI: 10.1080/17512433.2021.1903316 -
European Journal of Haematology Aug 2015Effective management of sickle cell pain entails a thorough understanding of its pathophysiology and the pharmacogenomics of the opioids used to manage it. In recent... (Review)
Review
Effective management of sickle cell pain entails a thorough understanding of its pathophysiology and the pharmacogenomics of the opioids used to manage it. In recent years, there has been significant progress along these two lines. At the pathophysiologic level, there is evidence that the severity and frequency of painful stimuli modulate their transmission at the level of the dorsal horn of the spinal cord. This modulation is achieved via two channels: the α-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) and NMDA receptors. Initially, the AMPA channel controls the transmission of stimuli of mild-moderate severity. Once the AMPA channel reaches its limit of membrane depolarization, the NMDA channel is activated and facilitates the transmission of painful stimuli in a progressive fashion leading to central sensitization and glial activation. At the level of pharmacogenomics, the metabolism of each opioid is patient-specific. Glucuronidation is unique for the metabolism of morphine, hydromorphone, and oxymorphone. The metabolism of all other opioids requires specific Cytochrome P450 (CYP) isoenzymes. The activity of each isoenzyme and the activity of the metabolites of each opioid vary among patients depending on their genetic makeup and coexistent environmental factors such as the use of other medications that may enhance or inhibit the CYP isoenzyme activity.
Topics: Analgesics, Opioid; Anemia, Sickle Cell; Humans; Pain; Pharmacogenetics
PubMed: 25288149
DOI: 10.1111/ejh.12460 -
International Journal of Environmental... May 2020There have been dynamic changes in prescription opioid use in the US but the state level policy factors contributing to these are incompletely understood. We examined...
There have been dynamic changes in prescription opioid use in the US but the state level policy factors contributing to these are incompletely understood. We examined the association between the legalization of recreational marijuana and prescription opioid distribution in Colorado. Utah and Maryland, two states that had not legalized recreational marijuana, were selected for comparison. Prescription data reported to the Drug Enforcement Administration for nine opioids used for pain (e.g., fentanyl, morphine, hydrocodone, hydromorphone, oxycodone, oxymorphone) and two primarily for opioid use disorder (OUD, methadone and buprenorphine) from 2007 to 2017 were evaluated. Analysis of the interval pre (2007-2012) versus post (2013-2017) marijuana legalization revealed statistically significant decreases for Colorado ( < 0.05) and Maryland ( < 0.01), but not Utah, for pain medications. There was a larger reduction from 2012 to 2017 in Colorado (-31.5%) than the other states (-14.2% to -23.5%). Colorado had a significantly greater decrease in codeine and oxymorphone than the comparison states. The most prevalent opioids by morphine equivalents were oxycodone and methadone. Due to rapid and pronounced changes in prescription opioid distribution over the past decade, additional study with more states is needed to determine whether cannabis policy was associated with reductions in opioids used for chronic pain.
Topics: Analgesics, Opioid; Cannabis; Colorado; Humans; Legislation, Drug; Maryland; Oxycodone; Practice Patterns, Physicians'; United States
PubMed: 32392702
DOI: 10.3390/ijerph17093251 -
Journal of Analytical Toxicology Jun 2017Desomorphine ("Krokodil") is a semi-synthetic opioid that has drawn attention as a recreational drug, particularly in Russia, neighboring former Soviet Republics,...
Desomorphine ("Krokodil") is a semi-synthetic opioid that has drawn attention as a recreational drug, particularly in Russia, neighboring former Soviet Republics, Eastern and Central Europe. It has no accepted medicinal uses and is currently a schedule I drug in the United States. In clandestine environments, desomorphine is synthesized from codeine using red phosphorous, hydroiodic acid and gasoline. Residual starting materials in illicit preparations have been associated with severe dermatological effects and extensive tissue necrosis. Desomorphine is not well studied, and there are limited reports concerning its pharmacology or detection in biological matrices. Immunoassays are widely relied upon for both antemortem and postmortem toxicology screening. Although desomorphine is an opioid of the phenanthrene-type, its ability to bind to conventional opioid antibodies has not been described. In this report we describe the cross-reactivity of desomorphine using six commercially available enzyme-linked immunosorbent assays (Immunalysis Opiates Direct ELISA, Immunalysis Oxycodone/Oxymorphone Direct ELISA, Randox Opiate ELISA, OraSure Technologies OTI Opiate Micro-plate EIA, Neogen Opiate Group ELISA and Neogen Oxycodone/Oxymorphone ELISA). Cross-reactivites were highly variable between assays, ranging from 77 to <2.5%. In general, assays directed towards morphine produced greater cross-reactivity with desomorphine than those directed towards oxycodone. The Immunalysis Opiates Direct ELISA produced the greatest cross-reactivity, although several of the assays evaluated produced cross-reactivity of a sufficient magnitude to be effective for desomorphine screening.
Topics: Analgesics, Opioid; Codeine; Enzyme-Linked Immunosorbent Assay; Humans; Illicit Drugs; Oxycodone; Substance Abuse Detection
PubMed: 28369523
DOI: 10.1093/jat/bkx024 -
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 -
Journal of Pharmaceutical and... Sep 2021A range of opioids are commonly prescribed to manage chronic pain, but individual patient responses vary greatly, especially in older populations. One source of that...
Simultaneous LC-MS/MS quantification of oxycodone, tramadol and fentanyl and their metabolites (noroxycodone, oxymorphone, O- desmethyltramadol, N- desmethyltramadol, and norfentanyl) in human plasma and whole blood collected via venepuncture and volumetric absorptive micro sampling.
INTRODUCTION
A range of opioids are commonly prescribed to manage chronic pain, but individual patient responses vary greatly, especially in older populations. One source of that variability are differences in absorption, metabolism and excretion, i.e. pharmacokinetics. Blood, plasma and serum concentrations of opioids allow that variability to be quantified and may be used to optimise opioid dosing. As an aid to that process, there is an unmet need to rapidly quantify several opioids and their metabolites in a single analytical method.
AIMS
To develop a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for simultaneous quantification of tramadol, oxycodone, fentanyl and their major metabolites in various human matrices.
METHODS
Sample preparation involved adding three deuterated internal standards followed by protein precipitation with 100 % acetonitrile, evaporation and reconstitution. Separation of analytes via LC was achieved on a reversed phase column via binary gradient elution using 0.005 % formic acid in water and 100 % acetonitrile as mobile phases. Analytes were detected via MS/MS with multiple reaction monitoring (MRM).
RESULTS
The method was accurate with the inter-day and intra-day accuracy of quality control samples (QCs) below 15 %. It was also precise with inter-day and intra-day coefficient of variation below 15 %. The lower limit of quantification (LLOQ) was 0.2 ng/mL for all analytes except tramadol and its metabolites, where the LLOQ was 10 ng/mL. Recovery was greater than 88 % for all analytes, except for O-desmethyltramadol (81 %). Analytes were stable over four freeze-thaw cycles, for 24 h on the bench top and for 24 h post-preparation. The inter- and intra-day variability of concentrations determined in blood and plasma were within 84-124%, whereas the inter- and intra-day variability for blood samples prepared using volumetric absorptive micro-sampling (VAMS) compared to those prepared from whole blood ranged between 83-122%.
CONCLUSION
A LC-MS/MS method is described that is able to accurately and precisely quantify a number of commonly prescribed opioids and their major metabolites in plasma and whole blood, including whole blood collected using VAMS.
Topics: Aged; Chromatography, Liquid; Fentanyl; Humans; Morphinans; Oxycodone; Oxymorphone; Reproducibility of Results; Tandem Mass Spectrometry; Tramadol
PubMed: 34087551
DOI: 10.1016/j.jpba.2021.114171 -
The Cochrane Database of Systematic... Sep 2014Osteoarthritis is the most common form of joint disease and the leading cause of pain and physical disability in older people. Opioids may be a viable treatment option... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Osteoarthritis is the most common form of joint disease and the leading cause of pain and physical disability in older people. Opioids may be a viable treatment option if people have severe pain or if other analgesics are contraindicated. However, the evidence about their effectiveness and safety is contradictory. This is an update of a Cochrane review first published in 2009.
OBJECTIVES
To determine the effects on pain, function, safety, and addiction of oral or transdermal opioids compared with placebo or no intervention in people with knee or hip osteoarthritis.
SEARCH METHODS
We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE and CINAHL (up to 28 July 2008, with an update performed on 15 August 2012), checked conference proceedings, reference lists, and contacted authors.
SELECTION CRITERIA
We included randomised or quasi-randomised controlled trials that compared oral or transdermal opioids with placebo or no treatment in people with knee or hip osteoarthritis. We excluded studies of tramadol. We applied no language restrictions.
DATA COLLECTION AND ANALYSIS
We extracted data in duplicate. We calculated standardised mean differences (SMDs) and 95% confidence intervals (CI) for pain and function, and risk ratios for safety outcomes. We combined trials using an inverse-variance random-effects meta-analysis.
MAIN RESULTS
We identified 12 additional trials and included 22 trials with 8275 participants in this update. Oral oxycodone was studied in 10 trials, transdermal buprenorphine and oral tapentadol in four, oral codeine in three, oral morphine and oral oxymorphone in two, and transdermal fentanyl and oral hydromorphone in one trial each. All trials were described as double-blind, but the risk of bias for other domains was unclear in several trials due to incomplete reporting. Opioids were more beneficial in pain reduction than control interventions (SMD -0.28, 95% CI -0.35 to -0.20), which corresponds to a difference in pain scores of 0.7 cm on a 10-cm visual analogue scale (VAS) between opioids and placebo. This corresponds to a difference in improvement of 12% (95% CI 9% to 15%) between opioids (41% mean improvement from baseline) and placebo (29% mean improvement from baseline), which translates into a number needed to treat (NNTB) to cause one additional treatment response on pain of 10 (95% CI 8 to 14). Improvement of function was larger in opioid-treated participants compared with control groups (SMD -0.26, 95% CI -0.35 to -0.17), which corresponds to a difference in function scores of 0.6 units between opioids and placebo on a standardised Western Ontario and McMaster Universities Arthritis Index (WOMAC) disability scale ranging from 0 to 10. This corresponds to a difference in improvement of 11% (95% CI 7% to 14%) between opioids (32% mean improvement from baseline) and placebo (21% mean improvement from baseline), which translates into an NNTB to cause one additional treatment response on function of 11 (95% CI 7 to 14). We did not find substantial differences in effects according to type of opioid, analgesic potency, route of administration, daily dose, methodological quality of trials, and type of funding. Trials with treatment durations of four weeks or less showed larger pain relief than trials with longer treatment duration (P value for interaction = 0.001) and there was evidence for funnel plot asymmetry (P value = 0.054 for pain and P value = 0.011 for function). Adverse events were more frequent in participants receiving opioids compared with control. The pooled risk ratio was 1.49 (95% CI 1.35 to 1.63) for any adverse event (9 trials; 22% of participants in opioid and 15% of participants in control treatment experienced side effects), 3.76 (95% CI 2.93 to 4.82) for drop-outs due to adverse events (19 trials; 6.4% of participants in opioid and 1.7% of participants in control treatment dropped out due to adverse events), and 3.35 (95% CI 0.83 to 13.56) for serious adverse events (2 trials; 1.3% of participants in opioid and 0.4% of participants in control treatment experienced serious adverse events). Withdrawal symptoms occurred more often in opioid compared with control treatment (odds ratio (OR) 2.76, 95% CI 2.02 to 3.77; 3 trials; 2.4% of participants in opioid and 0.9% of participants control treatment experienced withdrawal symptoms).
AUTHORS' CONCLUSIONS
The small mean benefit of non-tramadol opioids are contrasted by significant increases in the risk of adverse events. For the pain outcome in particular, observed effects were of questionable clinical relevance since the 95% CI did not include the minimal clinically important difference of 0.37 SMDs, which corresponds to 0.9 cm on a 10-cm VAS.
Topics: Administration, Cutaneous; Administration, Oral; Analgesics, Opioid; Humans; Osteoarthritis, Hip; Osteoarthritis, Knee; Pain Measurement; Randomized Controlled Trials as Topic
PubMed: 25229835
DOI: 10.1002/14651858.CD003115.pub4 -
Biochemical Pharmacology Apr 2022Opioids, and numerous centrally active drugs, are metabolized by cytochrome P450 2D (CYP2D). There are sex and estrous cycle differences in brain oxycodone analgesia....
Opioids, and numerous centrally active drugs, are metabolized by cytochrome P450 2D (CYP2D). There are sex and estrous cycle differences in brain oxycodone analgesia. Here we investigated the mechanism examining the selective role of CYP2D in the brain on sex, estrous cycle, and hormonal regulation. Propranolol, CYP2D-specific mechanism-based inhibitor, or vehicle was delivered into cerebral ventricles 24 h before administering oxycodone (or oxymorphone, negative control) orally to male and female (in estrus and diestrus) rats. Ovariectomized and sham-operated females received no treatment, estradiol, progesterone or vehicle. Analgesia was measured using tail-flick latency, and brain drug and metabolite concentrations were measured by microdialysis. Data were analyzed by two-way or mixed ANOVA. Following propranolol (versus vehicle) inhibition and oral oxycodone, there were greater increases in brain oxycodone concentrations and analgesia, and greater decreases in brain oxymorphone/oxycodone ratios (an in vivo phenotype of CYP2D in brain) in males and females in estrus, compared to females in diestrus; with no impact on plasma drug concentrations. There was no impact of propranolol pre-treatment, sex, or cycle after oral oxymorphone (non-CYP2D substrate) on brain oxymorphone concentrations or analgesia. There was no impact of propranolol pre-treatment following ovariectomy on brain oxycodone concentrations or analgesia, which was restored in ovariectomized females following estradiol, but not progesterone, treatment. Sex, cycle, and estradiol regulation of CYP2D in brain in turn altered brain oxycodone concentration and response, which may contribute to the large inter-individual variation in response to the numerous centrally acting CYP2D substrate drugs, including opioids.
Topics: Analgesia; Analgesics, Opioid; Animals; Brain; Cytochrome P-450 Enzyme System; Estradiol; Estrous Cycle; Female; Male; Oxycodone; Oxymorphone; Pain; Progesterone; Propranolol; Rats; Rats, Wistar
PubMed: 35143755
DOI: 10.1016/j.bcp.2022.114949 -
American Health & Drug Benefits Mar 2022The opioid epidemic and drug abuse are critical public health challenges in the United States. The number of deaths from exceeding the recommended opioid dose is...
BACKGROUND
The opioid epidemic and drug abuse are critical public health challenges in the United States. The number of deaths from exceeding the recommended opioid dose is increasing.
OBJECTIVE
To describe the recent trends in utilization, spending, and cost of opioid medications in the US Medicaid population between 1991 and 2019.
METHODS
This retrospective, descriptive study was designed to evaluate the utilization of, spending on, and cost of opioids from 1991 to 2019 in the Medicaid population. We extracted data from the Centers for Medicare & Medicaid Services national Medicaid pharmacy files. The opioids received included fentanyl, meperidine, morphine, hydromorphone, oxymorphone, hydrocodone, hydrocodone plus acetaminophen, oxycodone, oxycodone plus acetaminophen, tapentadol, and tramadol. The number of prescriptions and reimbursement spending were calculated for each medication per quarter year. The average per-prescription reimbursement as a proxy of drug price was calculated as the reimbursement amount divided by the number of prescriptions per quarter year. The market shares by spending and utilization were also calculated for each opioid medication.
RESULTS
The number of all opioid prescriptions in Medicaid increased from approximately 2.1 million in 1991 to approximately 41.6 million in 2015, and then reduced to approximately 19.1 million in 2019. During this 29-year study period, the opioid medications that were used as monotherapy were hydrocodone (246.8 million prescriptions), oxycodone (111.9 million prescriptions), and tramadol (75.2 million prescriptions). The total spending in the Medicaid population on opioids was $19.4 billion, including approximately $7.3 billion spending on oxycodone, approximately $3.7 billion on fentanyl, and approximately $3.3 billion on hydrocodone. The majority of opioid prices increased over time, and the highest average costs per opioid prescription in 2019 were $1188 for oxymorphone, $641 for tapentadol, and $198 for fentanyl.
CONCLUSIONS
The utilization of and spending on opioid medications in Medicaid increased over time, peaked in 2015, and then declined with the initiation of nationwide programs to combat the opioid epidemic. Effective cost-containment strategies and programs to combat the abuse of opioids are warranted in Medicaid programs.
PubMed: 35586617
DOI: No ID Found -
Traffic Injury Prevention Nov 2017The objective of this study was to look for dose- and concentration-effect relationships in experimental studies on single-dose administration of morphine on... (Review)
Review
Acute impairing effects of morphine related to driving: A systematic review of experimental studies to define blood morphine concentrations related to impairment in opioid-naïve subjects.
OBJECTIVE
The objective of this study was to look for dose- and concentration-effect relationships in experimental studies on single-dose administration of morphine on traffic-relevant behavioral tests by a systematic literature review and possibly to see whether a dose/concentration could be defined below which few or no tests would be affected.
METHODS
Searches for corresponding literature were conducted using MEDLINE, EMBASE, and PsycINFO, throughout March of 2016. The search strategy consisted of words colligated to cognitive and psychomotor functions of relevance to driving, in relation to morphine administration. The tests were arranged in main groups, and tests showing impairment were categorized by doses as well as calculated plasma concentrations.
RESULTS
Fifteen studies were included in the review. Impairment after the administration of a single intravenously dose of morphine was found in some of the tests on reaction time, attention, and visual functions. No impairment was observed in tests on psychomotor skills and en-/decoding. Tests on reaction time appeared to be less sensitive to the morphine administration, whereas tests on visual functions and attention appeared to be the most sensitive to the morphine administration. Single-dose administration of morphine with dosages up to 5 mg appeared to cause very few effects on traffic-relevant performance tasks. At higher dosages, impairment was found on various tasks but with no clear dose-effect relationship. Plasma morphine concentrations less than 50 nmol/L are most probably accompanied by few effects on traffic-relevant performance tasks.
CONCLUSIONS
A plasma morphine concentration of 50 nmol/L (approximately 14.3 ng/mL) could represent an upper level, under which there is little accompanying road traffic risk. A single dose of 5 mg morphine IV and analgetic equivalence doses of fentanyl, hydromorphone, oxycodone, and oxymorphone are presented with the suggestion that few traffic-relevant effects will appear after such doses.
Topics: Attention; Driving Under the Influence; Humans; Morphine; Psychomotor Performance; Reaction Time; Visual Acuity
PubMed: 28481682
DOI: 10.1080/15389588.2017.1326595