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Ugeskrift For Laeger Feb 1994
Topics: Denmark; Fatal Outcome; Female; Forensic Medicine; Humans; Methadone; Middle Aged
PubMed: 8116098
DOI: No ID Found -
Drug and Alcohol Dependence Mar 1978Cerebral spinal fluid (CSF) levels of methadone were measured in nine methadone maintenance patients requiring lumbar punctures for medical or surgical treatment....
Cerebral spinal fluid (CSF) levels of methadone were measured in nine methadone maintenance patients requiring lumbar punctures for medical or surgical treatment. Concurrent serum methadone levels were also determined. The CSF concentration of methadone in all cases was a fraction of the corresponding serum level--ranging from 2 to 73%. The CSF concentrations of methadone ranged from 0.010 to 0.097 ng%. Peak methadone levels in CSF appeared approximately 3 - 8 hours after methadone administration.
Topics: Humans; Methadone; Time Factors
PubMed: 631010
DOI: 10.1016/0376-8716(78)90022-4 -
Annual Review of Medicine 1973
Review
Topics: Dose-Response Relationship, Drug; Humans; Methadone; Substance Withdrawal Syndrome; Substance-Related Disorders
PubMed: 4575849
DOI: 10.1146/annurev.me.24.020173.001101 -
Analytical Methods : Advancing Methods... Nov 2020In the present work, to enhance the properties of a pencil graphite electrode (PGE), highly functionalized carbon quantum dots (CQDs) were synthesized and mixed with...
An innovative highly sensitive electrochemical sensor based on modified electrode with carbon quantum dots and multiwall carbon nanotubes for determination of methadone hydrochloride in real samples.
In the present work, to enhance the properties of a pencil graphite electrode (PGE), highly functionalized carbon quantum dots (CQDs) were synthesized and mixed with multiwall carbon nanotubes (MWCNTs) as novel modifiers for the preparation of working electrodes. These modifiers exhibited unique characteristics owing to the fascinating and well-defined properties of the CQD-MWCNT nanocomposite, including high surface to volume ratio, high conductivity, high stability and excellent electrocatalytic activity. Consequently, a modified pencil graphite electrode based on poly (diallyldimethylammonium chloride) (PDDA)/MWCNT/CQD was used to monitor the oxidation signals of methadone hydrochloride. Notably, field emission scanning electron microscopy (FE-SEM) was used to characterize the morphology and features of the different modifiers on the electrode surface. The proposed sensor was characterized via electrochemical studies including differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS). Under the optimum experimental conditions, the current response and concentration of methadone exhibited a linear relationship in the range of 0.1-225 μM with a detection limit of 0.03 μM. Furthermore, this sensor was successfully applied to determine methadone in human urine and plasma samples.
Topics: Electrochemical Techniques; Electrodes; Humans; Limit of Detection; Methadone; Nanotubes, Carbon; Quantum Dots
PubMed: 33078768
DOI: 10.1039/d0ay01374a -
The Journal of Clinical Psychiatry Dec 2006
Topics: Adult; Aggression; Disruptive, Impulse Control, and Conduct Disorders; Female; Humans; Inpatients; Intellectual Disability; Methadone; Narcotics
PubMed: 17194288
DOI: 10.4088/jcp.v67n1226f -
Journal of Veterinary Pharmacology and... Oct 2009Methadone hydrochloride is a synthetic mu-opioid receptor agonist with potent analgesic properties. Oral methadone has been successfully used in human medicine and may...
Methadone hydrochloride is a synthetic mu-opioid receptor agonist with potent analgesic properties. Oral methadone has been successfully used in human medicine and may overcome some limitations of other analgesics in equine species for producing analgesia with minimal adverse effects. However, there are no studies describing the pharmacokinetics (PK) of oral opioids in horses. The aim of this study was to describe the PK of orally administered methadone (0.1, 0.2 and 0.4 mg/kg) and physical effects in 12 healthy adult horses. Serum methadone concentrations were measured by gas chromatography/mass spectrometry at predetermined time points for 24 h, and PK parameters were estimated using a noncompartmental model. Physical effects were observed and recorded by experienced clinicians. No drug toxicity, behavioural or adverse effects were observed in the horses. The disposition of methadone followed first order elimination and a biphasic serum profile with rapid absorption and elimination phases. The PK profile of methadone was characterized by high clearance (Cl/F), small volume of distribution (V(d)/F) and short elimination half-life (t(1/2)). The mean of the estimated t(1/2) (SD) for each dose (0.1, 0.2 and 0.4 mg/kg) was 2.2 (35.6), 1.3 (46.1) and 1.5 (40.8), and the mean for the estimated C(max) (SD) was 33.9 (6.7), 127.9 (36.0) and 193.5 (65.8) respectively.
Topics: Administration, Oral; Analgesics, Opioid; Animals; Dose-Response Relationship, Drug; Female; Horses; Male; Methadone
PubMed: 19754917
DOI: 10.1111/j.1365-2885.2009.01071.x -
The Journal of Pharmacology and... Apr 1981A radioimmunoassay for the quantitation of methadone in biofluids is described. The antiserum was prepared by using an albumin conjugate of...
A radioimmunoassay for the quantitation of methadone in biofluids is described. The antiserum was prepared by using an albumin conjugate of N-methyl-N-(1-methyl-3,3-diphenyl-4-oxohexyl)aminoethanol succinate. By employing tritium-labeled dl-methadone as the radioligand and a sample volume of 0.05 ml, the method has a lower limit of sensitivity of 3 ng/ml. The ability of the antiserum to detect methadone was not influenced by the presence of the metabolites of methadone or members of the methadol series. Morphine, codeine, levorphanol, meperidine, l, alpha-acetylmethadol and d-propoxyphene do not cross-react. After the i.v. administration of 0.90 or 1.5 mg/kg of methadone to male rats, plasma methadone levels decline biexponentially and elimination is independent of dose. The mean volume of distribution is 7.58 +/- 0.87 liters/kg; the mean elimination T 1/2 is 88.6 +/- 1.9 min and the plasma clearance is 59.3 +/- 1.4 ml/min/kg. These results demonstrate that methadone is eliminated by the rat much more rapidly than previously suspected.
Topics: Animals; Kinetics; Male; Methadone; Radioimmunoassay; Rats
PubMed: 7205649
DOI: No ID Found -
Journal of Veterinary Pharmacology and... Jun 2014Buccal administration of buprenorphine is commonly used to treat pain in cats. It has been argued that absorption of buprenorphine through the buccal mucosa is high, in... (Randomized Controlled Trial)
Randomized Controlled Trial
Buccal administration of buprenorphine is commonly used to treat pain in cats. It has been argued that absorption of buprenorphine through the buccal mucosa is high, in part due to its pKa of 8.24. Morphine, methadone, hydromorphone, and oxymorphone have a pKa between 8 and 9. This study characterized the bioavailability of these drugs following buccal administration to cats. Six healthy adult female spayed cats were used. Buccal pH was measured prior to drug administration. Morphine sulfate, 0.2 mg/kg IV or 0.5 mg/kg buccal; methadone hydrochloride, 0.3 mg/kg IV or 0.75 mg/kg buccal; hydromorphone hydrochloride, 0.1 mg/kg IV or 0.25 mg/kg buccal; or oxymorphone hydrochloride, 0.1 mg/kg IV or 0.25 mg/kg buccal were administered. All cats received all treatments. Arterial blood was sampled immediately prior to drug administration and at various times up to 8 h thereafter. Bioavailability was calculated as the ratio of the area under the time-concentration curve following buccal administration to that following IV administration, each indexed to the administered dose. Mean ± SE (range) bioavailability was 36.6 ± 5.2 (12.7-49.5), 44.2 ± 7.9 (18.7-70.5), 22.4 ± 6.9 (6.4-43.4), and 18.8 ± 2.0 (12.9-23.5)% for buccal administration of morphine, methadone, hydromorphone, and oxymorphone, respectively. Bioavailability of methadone was significantly higher than that of oxymorphone.
Topics: Administration, Buccal; Analgesics, Opioid; Animals; Biological Availability; Cats; Female; Hydromorphone; Methadone; Morphine; Oxymorphone
PubMed: 24236993
DOI: 10.1111/jvp.12090 -
JAMA Internal Medicine Mar 2015Growing methadone use in pain management has raised concerns regarding its safety relative to other long-acting opioids. Methadone hydrochloride may increase the risk... (Comparative Study)
Comparative Study
IMPORTANCE
Growing methadone use in pain management has raised concerns regarding its safety relative to other long-acting opioids. Methadone hydrochloride may increase the risk for lethal respiratory depression related to accidental overdose and life-threatening ventricular arrhythmias.
OBJECTIVE
To compare the risk of out-of-hospital death in patients receiving methadone for noncancer pain with that in comparable patients receiving sustained-release (SR) morphine sulfate.
DESIGN, SETTING, AND PARTICIPANTS
A retrospective cohort study was conducted using Tennessee Medicaid records from 1997 through 2009. The cohort included patients receiving morphine SR or methadone who were aged 30 to 74 years, did not have cancer or another life-threatening illness, and were not in a hospital or nursing home. At cohort entry, 32 742 and 6014 patients had filled a prescription for morphine SR or methadone, respectively. The patients' median age was 48 years, 57.9% were female, and comparable proportions had received cardiovascular, psychotropic, and other musculoskeletal medications. Nearly 90% of the patients received the opioid for back pain or other musculoskeletal pain. The median doses prescribed for morphine SR and methadone were 90 mg/d and 40 mg/d, respectively.
MAIN OUTCOMES AND MEASURES
The primary study end point was out-of-hospital mortality, given that opioid-related deaths typically occur outside the hospital.
RESULTS
There were 477 deaths during 28 699 person-years of follow-up (ie, 166 deaths per 10 000 person-years). After control for study covariates, patients receiving methadone had a 46% increased risk of death during the follow-up period, with an adjusted hazard ratio (HR) of 1.46 (95% CI, 1.17-1.83; P < .001), resulting in 72 (95% CI, 27-130) excess deaths per 10 000 person-years of follow-up. Methadone doses of 20 mg/d or less, the lowest dose quartile, were associated with an increased risk of death (HR, 1.59; 95% CI, 1.01-2.51, P = .046) relative to a comparable dose of morphine SR (<60 mg/d).
CONCLUSIONS AND RELEVANCE
The increased risk of death observed for patients receiving methadone in this retrospective cohort study, even for low doses, supports recommendations that it should not be a drug of first choice for noncancer pain.
Topics: Adult; Aged; Cohort Studies; Death, Sudden; Delayed-Action Preparations; Female; Humans; Male; Methadone; Middle Aged; Morphine; Pain Management; Retrospective Studies
PubMed: 25599329
DOI: 10.1001/jamainternmed.2014.6294 -
Lancet (London, England) May 1993
Topics: Cause of Death; Humans; Methadone; Substance-Related Disorders; Switzerland
PubMed: 8098414
DOI: No ID Found