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Journal of Analytical Toxicology Sep 2021Methylphenidate (MPH) is a medication used to combat attention-deficit/hyperactivity disorder by speeding up brain activity. MPH has two chiral centers; however,...
Methylphenidate (MPH) is a medication used to combat attention-deficit/hyperactivity disorder by speeding up brain activity. MPH has two chiral centers; however, d-threo-MPH is responsible for its effects. Few studies have analyzed MPH and its metabolites, ritalinic acid (RA) and ethylphenidate (EPH), in blood. Stability studies are crucial in a forensic setting to provide insight on ideal storage conditions and analysis time. In this study, d,l-MPH, d,l-EPH and RA were analyzed at two concentrations (15 and 150 ng/mL) over 5 months at room temperature (∼25°C), refrigerated (4°C), frozen (-20°C) and elevated (35°C) temperatures. Analytes were analyzed using a validated liquid chromatography--mass spectrometry method. RA concentrations increased 53% at 25°C after 24 h, while d- and l-MPH concentrations dropped 18.1 and 20.6%, respectively. Additionally, d- and l-EPH concentrations decreased 22.3 and 28.8%, respectively. All analytes were stable at 4°C for 1 week (±17% change). At -20°C, all analytes were stable for 5 months. At 35°C, l-EPH remained stable for 24 h (14.4% loss) at the high concentration, while RA increased 244%. Losses of 64.1, 68.7 and 27.2% were observed for d- MPH, l-MPH and d-EPH, respectively. Due to this, a follow-up study was designed to assess the breakdown of MPH. The short-term experiment assessed d,l-MPH at two concentrations for 1 month in the same conditions. As MPH decreased, RA concentrations rose. At 25°C, it took 2 weeks for MPH to metabolize completely into RA. In refrigerated and frozen temperatures, MPH did not completely metabolize to RA. In elevated temperatures, MPH broke down to RA within 2 weeks. Due to this, it was concluded that d,l-MPH breaks down in the blood to its metabolite RA and may make data interpretation difficult if samples are not properly stored. The optimal storage for these analytes is recommended at -20°C.
Topics: Chromatography, Liquid; Follow-Up Studies; Mass Spectrometry; Methylphenidate
PubMed: 34086899
DOI: 10.1093/jat/bkab063 -
Journal of Veterinary Pharmacology and... Jul 2022Robenacoxib is a veterinary-approved non-steroidal anti-inflammatory drug (NSAID) of the coxib group. It possesses anti-hyperalgesic, anti-inflammatory and anti-pyretic... (Review)
Review
Robenacoxib is a veterinary-approved non-steroidal anti-inflammatory drug (NSAID) of the coxib group. It possesses anti-hyperalgesic, anti-inflammatory and anti-pyretic properties. Robenacoxib inhibits the cyclooxygenase (COX)-2 isoform of COX selectively (in vitro IC ratios COX-1:COX-2, 129:1 in dogs, 32:1 in cats). At registered dosages (2 mg/kg subcutaneously in dogs and cats, 1-4 mg/kg orally in dogs and 1-2.4 mg/kg orally in cats), robenacoxib produces significant inhibition of COX-2 whilst sparing COX-1. The pharmacokinetic (PK) profile of robenacoxib is characterized by a high degree of binding to plasma proteins (>98%) and moderate volume of distribution (at steady state, 240 ml/kg in dogs and 190 ml/kg in cats). In consequence, the terminal half-life in blood (<2 h) is short, despite moderate body clearance (0.81 L/kg/h) in dogs and low clearance (0.44 L/kg/h) in cats. Excretion is principally in the bile (65% in dogs and 72% in cats). Robenacoxib concentrates in inflamed tissues, and clinical efficacy is achieved with once-daily dosing, despite the short blood terminal half-life. In dogs, no relevant breed differences in robenacoxib PK have been detected. Robenacoxib has a wide safety margin; in healthy laboratory animals daily oral doses 20-fold (dog, 1 month), eight-fold (cat, 6 weeks) and five-fold (dog, 6 months) higher than recommended clinical doses were well tolerated. Clinical efficacy and safety have been demonstrated in orthopaedic and soft tissue surgery, and in musculoskeletal disorders in dogs and cats.
Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Cat Diseases; Cats; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Diphenylamine; Dog Diseases; Dogs; Phenylacetates
PubMed: 35460083
DOI: 10.1111/jvp.13052 -
Journal of the American Academy of... May 2022The first paper indicating that a central nervous system stimulant (amphetamine) could be beneficial for children with attention-deficit/hyperactivity disorder... (Meta-Analysis)
Meta-Analysis
The first paper indicating that a central nervous system stimulant (amphetamine) could be beneficial for children with attention-deficit/hyperactivity disorder (ADHD)-like behavioral symptoms appeared in 1937. Over the subsequent 80 years, a range of additional stimulant (methylphenidate) and nonstimulant (atomoxetine, clonidine, guanfacine, and, most recently, viloxazine) drugs have been approved to treat children and adolescents with ADHD. These drug treatments have been the subject of a large number of randomized controlled trails (RCTs). A network meta-analysis found that using clinician ratings, amphetamine, methylphenidate, and atomoxetine were all significantly superior to a placebo. These findings suggest that in the short-term at least, these treatments are effective-data are sparse on the efficacy of longer-term drug treatment. However, there are longstanding worries about the use of such drug treatments with children. In particular there are concerns over possible adverse impact on growth. There are also less tangible, but important, concerns of parents as the whether it is appropriate to subject their children to the modification of behavior by drugs. For these reasons, there is an urgent need to develop nonpharmacological treatments for children and adolescents with ADHD. One such nonpharmacological treatment is dietary supplementation with micronutrients. In this issue of the Journal, Johnstone et al. present a study of micronutrients showing that, under the stringent conditions of an RCT, micronutrients substantially benefit the well-being of young people with ADHD and irritability (risk ratio [RR] = 2.97; 97.5% CI = 1.50-5.90).
Topics: Adolescent; Amphetamines; Atomoxetine Hydrochloride; Attention Deficit Disorder with Hyperactivity; Central Nervous System Stimulants; Child; Humans; Methylphenidate; Micronutrients
PubMed: 34416292
DOI: 10.1016/j.jaac.2021.08.008 -
Atherosclerosis Nov 2023Since plasma metabolites can modulate blood pressure (BP) and vary between men and women, we examined sex differences in plasma metabolite profiles associated with BP...
BACKGROUND AND AIMS
Since plasma metabolites can modulate blood pressure (BP) and vary between men and women, we examined sex differences in plasma metabolite profiles associated with BP and sympathicovagal balance. Our secondary aim was to investigate associations between gut microbiota composition and plasma metabolites predictive of BP and heart rate variability (HRV).
METHODS
From the HELIUS cohort, we included 196 women and 173 men. Office systolic BP and diastolic BP were recorded, and heart rate variability (HRV) and baroreceptor sensitivity (BRS) were calculated using finger photoplethysmography. Plasma metabolomics was measured using untargeted LC-MS/MS. Gut microbiota composition was determined using 16S sequencing. We used machine learning models to predict BP and HRV from metabolite profiles, and to predict metabolite levels from gut microbiota composition.
RESULTS
In women, best predicting metabolites for systolic BP included dihomo-lineoylcarnitine, 4-hydroxyphenylacetateglutamine and vanillactate. In men, top predictors included sphingomyelins, N-formylmethionine and conjugated bile acids. Best predictors for HRV in men included phenylacetate and gentisate, which were associated with lower HRV in men but not in women. Several of these metabolites were associated with gut microbiota composition, including phenylacetate, multiple sphingomyelins and gentisate.
CONCLUSIONS
Plasma metabolite profiles are associated with BP in a sex-specific manner. Catecholamine derivatives were more important predictors for BP in women, while sphingomyelins were more important in men. Several metabolites were associated with gut microbiota composition, providing potential targets for intervention.
Topics: Humans; Male; Female; Blood Pressure; Heart Rate; Sphingomyelins; Sex Characteristics; Chromatography, Liquid; Gentisates; Tandem Mass Spectrometry; Phenylacetates
PubMed: 37286456
DOI: 10.1016/j.atherosclerosis.2023.05.016 -
The Science of the Total Environment Oct 2021The presence of the non-steroidal anti-inflammatory drugs (NSAIDs) in the environment is a fact, and aquatic and soil organisms are chronically exposed to trace levels... (Review)
Review
The presence of the non-steroidal anti-inflammatory drugs (NSAIDs) in the environment is a fact, and aquatic and soil organisms are chronically exposed to trace levels of these emerging pollutants. This review presents the current state of knowledge on the metabolic pathways of NSAIDs in organisms at various levels of biological organisation. More than 150 publications dealing with target or non-target analysis of selected NSAIDs (mainly diclofenac, ibuprofen, and naproxen) were collected. The metabolites of phase I and phase II are presented. The similarity of NSAIDs metabolism to that in mammals was observed in bacteria, microalgae, fungi, higher plants, invertebrates, and vertebrates. The differences, such as newly detected metabolites, the extracellular metabolism observed in bacteria and fungi, or phase III metabolism in plants, are highlighted. Metabolites detected in plants (conjugates with sugars and amino acids) but not found in any other organisms are described. Selected, in-depth studies with isolated bacterial strains showed the possibility of transforming NSAIDs into assimilable carbon sources. It has been found that some of the metabolites show higher toxicity than their parent forms. The presence of metabolites of NSAIDs in the environment is the cumulative effect of their introduction with wastewaters, their formation in wastewater treatment plants, and their transformation by non-target wild-living organisms.
Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Diclofenac; Ibuprofen; Naproxen; Pharmaceutical Preparations
PubMed: 34139498
DOI: 10.1016/j.scitotenv.2021.148251 -
AAPS PharmSciTech Feb 2021Poor physicomechanical properties and limited aqueous solubility restrict the bioavailability of aceclofenac when given orally. To improve its above properties,...
Poor physicomechanical properties and limited aqueous solubility restrict the bioavailability of aceclofenac when given orally. To improve its above properties, aceclofenac (ACE) was cocrystallized with dimethyl urea (DMU) in 1:2 molar ratio by dry and solvent assisted grinding. The cocrystals were characterized by ATR-FTIR, DSC, and PXRD, and their surface morphology was studied by SEM. There was enhancement in intrinsic dissolution rate (IDR) (~eight- and ~fivefold in cocrystals prepared by solvent assisted grinding (SAG) and solid state grinding (SSG), respectively, in 0.1 N HCl, pH 1.2) and similarly (~3.42-fold and ~1.20-fold in phosphate buffer, pH 7.4) as compared to pure drug. Additionally, mechanical properties were assessed by tabletability curves. The tensile strength of ACE was < 1 MPa in contrast to the cocrystal tensile strength (3.5 MPa) which was ~1.98 times higher at 6000 psi. The tablet formulation of cocrystal by direct compression displayed enhanced dissolution profile (~36% in 0.1 N HCl, pH 1.2, and ~100% in phosphate buffer, pH 7.4) in comparison to physical mixture (~ 30% and ~ 80%) and ACE (~18% and ~50%) after 60 min, respectively. Stability studies of cocrystal tablets for 3 months indicated a stable formulation. Pharmacokinetic studies were performed by using rabbit model. The AUC (37.87±1.3 μgh/ml) and C (6.94±2.94 μg/ml) of the selected cocrystal C1 prepared by SAG were significantly enhanced (p < 0.05) and were ~3.43 and ~1.63-fold higher than that of ACE. In conclusion, new cocrystal of ACE-DMU was successfully prepared with improved tabletability, in vitro and in vivo properties.
Topics: Animals; Crystallization; Diclofenac; Drug Liberation; Drug Stability; Female; Male; Rabbits; Tablets; Urea
PubMed: 33564940
DOI: 10.1208/s12249-021-01938-7 -
The Medical Letter on Drugs and... Aug 2019
Review
Topics: Adult; Attention Deficit Disorder with Hyperactivity; Central Nervous System Stimulants; Child; Delayed-Action Preparations; Drug Administration Schedule; Drug Compounding; Drug Interactions; Female; Humans; Male; Methylphenidate; Pregnancy
PubMed: 31386648
DOI: No ID Found -
Journal of Labelled Compounds &... May 2024Fast and straightforward incorporation of radionuclides into pharmaceutically relevant molecules is one of the main barriers to preclinical and clinical tracer research....
Fast and straightforward incorporation of radionuclides into pharmaceutically relevant molecules is one of the main barriers to preclinical and clinical tracer research. Late-stage direct incorporation of cyclotron-produced [C]CO to afford carbon-11-labeled radiopharmaceuticals has the potential to provide ready-to-inject positron emission tomography agents in less than an hour. The present work describes photocatalyzed carboxylation of alkylbenzene derivatives to afford C-phenylacetic acids. Reaction conditions and scope are investigated followed by application of this methodology to the preparative radiosynthesis of [C]fenoprofen, a nonsteroidal anti-inflammatory drug.
Topics: Carbon Radioisotopes; Phenylacetates; Catalysis; Radiopharmaceuticals; Radiochemistry; Photochemical Processes; Chemistry Techniques, Synthetic
PubMed: 37941130
DOI: 10.1002/jlcr.4073 -
Expert Opinion on Pharmacotherapy 2023Attention deficit/hyperactivity disorder (ADHD) is a common behavioral disorder which is best treated through a combination of medication and behavioral therapy, with... (Review)
Review
INTRODUCTION
Attention deficit/hyperactivity disorder (ADHD) is a common behavioral disorder which is best treated through a combination of medication and behavioral therapy, with stimulant medications serving as a first-line treatment approach. Serdexmethylphenidate (SDX), a prodrug of dexmethylphenidate (d-MPH), a commonly utilized stimulant medication, has recently received approval and is marketed in the U.S.A.
AREAS COVERED
This review summarizes peer-reviewed literature on SDX published between 2021-2023 and a review of data available from ClinicalTrials.gov.
EXPERT OPINION
SDX represents a new option for treatment for ADHD. It is unique in its prodrug design and achieves a relatively extended duration of action in comparison to other stimulant formulations. Although the research is relatively limited thus far, early data suggests it to be a safe medication to consider with side effects being similar to other stimulant medications. Its prodrug design is useful in potentially serving as a deterrent to intentional parenteral abuse and its ability to be opened and sprinkled makes it an option for those individuals with ADHD who might be unable to swallow pills.
Topics: Humans; Attention Deficit Disorder with Hyperactivity; Central Nervous System Stimulants; Dexmethylphenidate Hydrochloride; Prodrugs; Methylphenidate
PubMed: 37226489
DOI: 10.1080/14656566.2023.2218544 -
Journal of Child and Adolescent... Jun 2022The study was designed to determine (1) the pharmacokinetic (PK) profile of dexmethylphenidate (d-MPH) after oral administration of three dosage strengths of a new...
Dose Proportionality and Steady-State Pharmacokinetics of Serdexmethylphenidate/Dexmethylphenidate, a Novel Prodrug Combination to Treat Attention-Deficit/Hyperactivity Disorder.
The study was designed to determine (1) the pharmacokinetic (PK) profile of dexmethylphenidate (d-MPH) after oral administration of three dosage strengths of a new treatment containing d-MPH and a novel prodrug, serdexmethylphenidate (SDX); (2) the dose proportionality of the different SDX/d-MPH dosages; and (3) the steady-state PK profile of d-MPH and SDX after multiple dosing of SDX/d-MPH. Twenty-three healthy volunteers (aged 18-55 years) under fasted conditions received in a crossover design SDX/d-MPH 26.1/5.2 mg (Treatment A), 39.2/7.8 mg (Treatment B), and 52.3/10.4 mg (Treatment C) for a total d-MPH hydrochloride equivalent dose of 20, 30, and 40 mg, respectively. After a 96-hour washout period, all participants received four consecutive daily doses of SDX/d-MPH 52.3/10.4 mg. Blood samples were collected for measurement of plasma d-MPH and SDX and for PK analysis. Administration of all three doses of SDX/d-MPH resulted in a rapid rise and slow decline in the plasma concentration of d-MPH. For Treatments A, B, and C, mean (± standard deviation) maximum concentrations () were 7.1 ± 2.1, 9.8 ± 2.8, and 13.8 ± 3.8 ng/mL, and overall exposures (AUC) were 97.2 ± 28.8, 142.5 ± 41.2, and 199.8 ± 57.2 h*ng/mL, respectively. Dose-normalized , AUC, and AUC for d-MPH were similar when comparing the high and low doses versus the middle dose. Power model regression analysis revealed that and AUC proportionally increased with an increase in SDX/d-MPH dose. In the multiple-dose study, d-MPH reached steady state before the third dose, and SDX after the first dose. The PK profile of SDX/d-MPH is characterized by a rapid rise and a gradual decline in d-MPH concentration, with proportional and AUC across doses. The PK attributes of SDX/d-MPH may optimize symptom control from early morning to early evening, while the demonstrated dose proportionality may facilitate initial dose titration and ongoing dose adjustment.
Topics: Area Under Curve; Attention Deficit Disorder with Hyperactivity; Biological Availability; Central Nervous System Stimulants; Cross-Over Studies; Delayed-Action Preparations; Dexmethylphenidate Hydrochloride; Humans; Methylphenidate; Prodrugs
PubMed: 35666231
DOI: 10.1089/cap.2022.0015