-
Neuropsychopharmacology : Official... Oct 2023Methylphenidate is a widely used and effective treatment for attention-deficit/hyperactivity disorder (ADHD), yet the underlying neural mechanisms and their relationship... (Randomized Controlled Trial)
Randomized Controlled Trial
Methylphenidate is a widely used and effective treatment for attention-deficit/hyperactivity disorder (ADHD), yet the underlying neural mechanisms and their relationship to changes in behavior are not fully understood. Specifically, it remains unclear how methylphenidate affects brain and behavioral dynamics, and the interplay between these dynamics, in individuals with ADHD. To address this gap, we used a novel Bayesian dynamical system model to investigate the effects of methylphenidate on latent brain states in 27 children with ADHD and 49 typically developing children using a double-blind, placebo-controlled crossover design. Methylphenidate remediated greater behavioral variability on a continuous performance task in children with ADHD. Children with ADHD exhibited aberrant latent brain state dynamics compared to typically developing children, with a single latent state showing particularly abnormal dynamics, which was remediated by methylphenidate. Additionally, children with ADHD showed brain state-dependent hyper-connectivity in the default mode network, which was also remediated by methylphenidate. Finally, we found that methylphenidate-induced changes in latent brain state dynamics, as well as brain state-related functional connectivity between salience and default mode networks, were correlated with improvements in behavioral variability. Taken together, our findings reveal a novel latent brain state dynamical process and circuit mechanism underlying the therapeutic effects of methylphenidate in childhood ADHD. We suggest that Bayesian dynamical system models may be particularly useful for capturing complex nonlinear changes in neural activity and behavioral variability associated with ADHD. Our approach may be of value to clinicians and researchers investigating the neural mechanisms underlying pharmacological treatment of psychiatric disorders.
Topics: Humans; Child; Methylphenidate; Attention Deficit Disorder with Hyperactivity; Bayes Theorem; Brain; Nerve Net; Central Nervous System Stimulants
PubMed: 37491674
DOI: 10.1038/s41386-023-01668-3 -
Molecules (Basel, Switzerland) Dec 20224-Arylhydrazinylidene-5-(polyfluoroalkyl)pyrazol-3-ones (4-AHPs) were found to be obtained by the regiospecific cyclization of...
4-Arylhydrazinylidene-5-(polyfluoroalkyl)pyrazol-3-ones (4-AHPs) were found to be obtained by the regiospecific cyclization of 2-arylhydrazinylidene-3-(polyfluoroalkyl)-3-oxoesters with hydrazines, by the azo coupling of 4-nonsubstituted pyrazol-5-oles with aryldiazonium chlorides or by the firstly discovered acid-promoted self-condensation of 2-arylhydrazinylidene-3-oxoesters. All the 4-AHPs had an acceptable ADME profile. Varying the substituents in 4-AHPs promoted the switching or combining of their biological activity. The polyfluoroalkyl residue in 4-AHPs led to the appearance of an anticarboxylesterase action in the micromolar range. An NH-fragment and/or methyl group instead of the polyfluoroalkyl one in the 4-AHPs promoted antioxidant properties in the ABTS, FRAP and ORAC tests, as well as anti-cancer activity against HeLa that was at the Doxorubicin level coupled with lower cytotoxicity against normal human fibroblasts. Some Ph-N-substituted 4-AHPs could inhibit the growth of bacteria at MIC 0.9 μg/mL. The possibility of using 4-AHPs for cell visualization was shown. Most of the 4-AHPs exhibited a pronounced analgesic effect in a hot plate test in vivo at and above the diclofenac and metamizole levels except for the ones with two chlorine atoms in the aryl group. The methylsulfonyl residue was proved to raise the anti-inflammatory effect also. A mechanism of the antinociceptive action of the 4-AHPs through blocking the TRPV1 receptor was proposed and confirmed using in vitro experiment and molecular docking.
Topics: Humans; Molecular Docking Simulation; Diclofenac; Antioxidants; Pharmaceutical Preparations
PubMed: 36615256
DOI: 10.3390/molecules28010059 -
American Journal of Health-system... Feb 2022To advance the implementation of consciousness-promoting therapies in patients with acute disorders of consciousness, the availability of potential therapeutic agents in...
PURPOSE
To advance the implementation of consciousness-promoting therapies in patients with acute disorders of consciousness, the availability of potential therapeutic agents in formulations suitable for administration in hospitalized patients in the presence of complex comorbid conditions is paramount. The purpose of this study is to evaluate the long-term stability of extemporaneously prepared preservative-free methylphenidate hydrochloride (HCl) 5 mg/mL intravenous solution for experimental use.
METHODS
A methylphenidate 5 mg/mL solution was prepared under proper aseptic techniques with Methylphenidate Hydrochloride, USP, powder mixed in sterile water for solution. Methylphenidate HCl 5 mg/mL solution was sterilized by filtration technique under USP <797>-compliant conditions. Samples were stored refrigerated (2-8°C) and analyzed at approximately days 1, 30, 60, 90, 180, and 365. At each time point, chemical and physical stability were evaluated by visual inspection, pH measurement, membrane filtration procedure, turbidometric or photometric technique, and high-performance liquid chromatography analysis.
RESULTS
Over the 1-year study period, the samples retained 96.76% to 102.04% of the initial methylphenidate concentration. There was no significant change in the visual appearance, pH level, or particulate matter during the study period. The sterility of samples was maintained and endotoxin levels were undetectable throughout the 1-year stability period.
CONCLUSION
Extemporaneously prepared preservative-free methylphenidate 5 mg/mL intravenous solution was physically and chemically stable at 32, 61, 95, 186, and 365 days when stored in amber glass vials at refrigerated temperatures (2-8°C).
Topics: Chromatography, High Pressure Liquid; Drug Compounding; Drug Stability; Drug Storage; Humans; Methylphenidate
PubMed: 34788364
DOI: 10.1093/ajhp/zxab420 -
Translational Psychiatry Sep 2023Stimulants, such as methylphenidate (MPH), are effective in treating attention-deficit/hyperactivity disorder (ADHD), but there is individual variability in response,...
Stimulants, such as methylphenidate (MPH), are effective in treating attention-deficit/hyperactivity disorder (ADHD), but there is individual variability in response, especially in adults. To improve outcomes, we need to understand the factors associated with adult treatment response. This longitudinal study investigated whether pre-treatment anatomy of the fronto-striatal and fronto-parietal attentional networks was associated with MPH treatment response. 60 adults with ADHD underwent diffusion brain imaging before starting MPH treatment, and response was measured at two months. We tested the association between brain anatomy and treatment response by using regression-based approaches; and compared the identified anatomical characteristics with those of 20 matched neurotypical controls in secondary analyses. Finally, we explored whether combining anatomical with clinical and neuropsychological data through machine learning provided a more comprehensive profile of factors associated with treatment response. At a group level, a smaller left dorsal superior longitudinal fasciculus (SLF I), a tract responsible for the voluntary control of attention, was associated with a significantly lower probability of being responders to two-month MPH-treatment. The association between the volume of the left SLF I and treatment response was driven by improvement on both inattentive and hyperactive/impulsive symptoms. Only non-responders significantly differed from controls in this tract metric. Finally, our machine learning approach identified clinico-neuropsychological factors associated with treatment response, such as higher cognitive performance and symptom severity at baseline. These novel findings add to our understanding of the pathophysiological mechanisms underlying response to MPH, pointing to the dorsal attentive network as playing a key role.
Topics: Adult; Humans; Attention Deficit Disorder with Hyperactivity; Longitudinal Studies; Methylphenidate; Central Nervous System Stimulants; Attention
PubMed: 37777529
DOI: 10.1038/s41398-023-02598-w -
International Journal of Molecular... Dec 2022This article describes the synthesis of new chiral 3-(piperidin-3-yl)-1H-indole derivatives and from the corresponding diastereomers: (3R, 2R) and (3S,...
This article describes the synthesis of new chiral 3-(piperidin-3-yl)-1H-indole derivatives and from the corresponding diastereomers: (3R, 2R) and (3S, 2R)-2-[3-(1H-indol-3-yl)-1-piperidyl]-2-phenyl-acetamides and . Diastereomers were obtained by N-alkylation of derivatives of racemic 3-(piperidin-3-yl)-1H-indoles using (S)-2-(4-toluenesulfonyloxy)-phenylacetic amide . The same method was applied to obtain (3R, 2S)-methyl-2-[3-(1H-indole-3-yl)-1-piperidyl]-2-phenylacetate and (3S, 2S)-methyl-2-[3-(1H-indole-3-yl)-1-piperidyl]-2-phenylacetate diastereomers by treating amine with (R)-2-(4-toluenesulfonyloxy)-phenylacetic acid methylester . Systematic studies via single crystal X-ray crystallography were used to determine the molecular structure of the racemates and the absolute configuration of the enantiomers. The solid racemates and were "true racemates" crystallizing in a centrosymmetric space group, while formed a racemic conglomerate of homoenantiomeric crystals. The absolute configuration was determined for the enantiomeric pairs , , and , as well as for . Spectra of H, CNMR, HPLC, and HRMS for diastereomers and enantiomers were consistent with the determined structures.
Topics: Molecular Structure; Stereoisomerism; Crystallography, X-Ray; Magnetic Resonance Spectroscopy; Alkylation
PubMed: 36613958
DOI: 10.3390/ijms24010517 -
PeerJ 2023Amultigenerational study on was carried out by exposing three subsequent generations to pharmaceuticals chlorpromazine (CPZ) and diclofenac (DCF), and two lanthanide...
Amultigenerational study on was carried out by exposing three subsequent generations to pharmaceuticals chlorpromazine (CPZ) and diclofenac (DCF), and two lanthanide chlorides, gadolinium as GdCl and europium as EuCl. As the treatments, environmentally relevant concentrations were chosen (0.001, 0.01 and 0.1 mg/L for CPZ; 0.1, 1 and 10 mg/L for DCF; 0.425, 4.25 and 42.5 µg/L for Gd and 0.41, 4.1 and 41 µg/L for Eu). Survival, population growth and reproduction success were evaluated at 21 and 30 days of exposure, and the whole observation period lasted 40 days. The least sensitive to all selected substances was the first daphnid generation (F1). Within 21-day exposure, no significant effects of the psychotropic drug CPZ on survival were observed in generations F1-F3. The anti-inflammatory drug DCF did not affect survival in the F1 generation; however, it significantly reduced survival in the F3 generation at 1-10 mg/L. Both lanthanides did not affect survival in the F1 and F2 generations of but considerably decreased survival in the F3 at 4-42 µg/L. Both pharmaceuticals stimulated the reproduction of in the F1 generation, while inhibition occurred at the highest tested concentrations in generations F2 and F3. The inhibitory effect on the reproductive success of lanthanides in the F2 generation resembled that for CPZ but not for DCF. The dynamics of adverse effects during the 21-30-day period revealed that despite increased mortality in the controls (up to 30%), concentrations used in the study minified, in most instances, the survival and aggravated population growth and reproduction success of . Our data suggest that as a test organism can be used for 21 days in multigenerational investigations, especially when testing close to environmental concentrations. In this respect, the standard chronic toxicity assay seems limited since prolonged observations and several generations of daphnids are required to obtain reliable information for the risk assessment of potentially aggressive chemicals.
Topics: Animals; Chlorpromazine; Cladocera; Diclofenac; Lanthanoid Series Elements
PubMed: 38025671
DOI: 10.7717/peerj.16472 -
Clinical Pharmacokinetics Apr 2022L-Ornithine phenylacetate is an intravenous formulation of the L-ornithine salt of phenylacetic acid under development for the treatment of hepatic encephalopathy. Very...
BACKGROUND AND OBJECTIVE
L-Ornithine phenylacetate is an intravenous formulation of the L-ornithine salt of phenylacetic acid under development for the treatment of hepatic encephalopathy. Very limited clinical data in patients are available, with a phase II study in target patients not designed for dose finding, to support phase III dose selection in a global development program. The objective of the present population pharmacokinetic modeling and simulation was to evaluate dose selection for target patient populations with a low body weight, ethnicity, and hepatic impairment in a global clinical study.
METHODS
A population pharmacokinetic model was developed based on plasma concentrations of L-ornithine, phenylacetic acid, and phenylacetylglutamine data from four clinical trials in healthy subjects and patients with stable cirrhosis or hospitalized adult patients with liver cirrhosis and hepatic encephalopathy. A covariate analysis was conducted to identify source of variability to support dose selection for global clinical development of L-ornithine phenylacetate. Phenylacetylglutamine formation in the pharmacokinetic model also quantified pharmacodynamic effects measured by ammonia removal.
RESULTS
Body weight and hepatic function were significant covariates determining phenylacetic acid exposure. After accounting for body weight, there was no difference between tested Caucasian and Asian populations in phenylacetic acid exposure. Renal dysfunction significantly reduced phenylacetylglutamine excretion. However, renal impairment had no impact on plasma phenylacetic acid and free ammonia levels. Exploratory modeling suggested that L-ornithine might enhance the removal of ammonia.
CONCLUSIONS
With a flat dosing algorithm, special consideration must be given to patients with a small body size (i.e., body weight ≤ 50 kg) and severe hepatic impairment.
Topics: Adult; Ammonia; Clinical Trials as Topic; Hepatic Encephalopathy; Humans; Ornithine; Phenylacetates
PubMed: 34786649
DOI: 10.1007/s40262-021-01075-1 -
Molecules (Basel, Switzerland) Feb 2022Cochlear implants, like other active implants, rely on precise and effective electrical stimulation of the target tissue but become encapsulated by different amounts of...
Cochlear implants, like other active implants, rely on precise and effective electrical stimulation of the target tissue but become encapsulated by different amounts of fibrous tissue. The current study aimed at the development of a dual drug release from a PLLA coating and from the bulk material to address short-term and long-lasting release of anti-inflammatory drugs. Inner-ear cytocompatibility of drugs was studied in vitro. A PLLA coating (containing diclofenac) of medical-grade silicone (containing 5% dexamethasone) was developed and release profiles were determined. The influence of different coating thicknesses (2.5, 5 and 10 µm) and loadings (10% and 20% diclofenac) on impedances of electrical contacts were measured with and without pulsatile electrical stimulation. Diclofenac can be applied to the inner ear at concentrations of or below 4 × 10 mol/L. Release of dexamethasone from the silicone is diminished by surface coating but not blocked. Addition of 20% diclofenac enhances the dexamethasone release again. All PLLA coatings serve as insulator. This can be overcome by using removable masking on the contacts during the coating process. Dual drug release with different kinetics can be realized by adding drug-loaded coatings to drug-loaded silicone arrays without compromising electrical stimulation.
Topics: Animals; Anti-Inflammatory Agents; Coated Materials, Biocompatible; Cochlear Implants; Dexamethasone; Diclofenac; Drug Delivery Systems; Drug Liberation; Rats; Rats, Sprague-Dawley
PubMed: 35209205
DOI: 10.3390/molecules27041417 -
Scientific Reports Sep 2023The formation of protein aggregates is a hallmark of many neurodegenerative diseases and systemic amyloidoses. These disorders are associated with the fibrillation of a...
The formation of protein aggregates is a hallmark of many neurodegenerative diseases and systemic amyloidoses. These disorders are associated with the fibrillation of a variety of proteins/peptides, which ultimately leads to cell toxicity and tissue damage. Understanding how amyloid aggregation occurs and developing compounds that impair this process is a major challenge in the health science community. Here, we demonstrate that pathogenic proteins associated with Alzheimer's disease, diabetes, AL/AA amyloidosis, and amyotrophic lateral sclerosis can aggregate within stress-inducible physiological amyloid-based structures, termed amyloid bodies (A-bodies). Using a limited collection of small molecule inhibitors, we found that diclofenac could repress amyloid aggregation of the β-amyloid (1-42) in a cellular setting, despite having no effect in the classic Thioflavin T (ThT) in vitro fibrillation assay. Mapping the mechanism of the diclofenac-mediated repression indicated that dysregulation of cyclooxygenases and the prostaglandin synthesis pathway was potentially responsible for this effect. Together, this work suggests that the A-body machinery may be linked to a subset of pathological amyloidosis, and highlights the utility of this model system in the identification of new small molecules that could treat these debilitating diseases.
Topics: Humans; Diclofenac; Amyloidogenic Proteins; Amyloidosis; Prostaglandin-Endoperoxide Synthases; Immunoglobulin Light-chain Amyloidosis
PubMed: 37660155
DOI: 10.1038/s41598-023-41712-2 -
Pharmacology, Biochemistry, and Behavior Jul 2022Prescription psychostimulants, such as methylphenidate (MPH), have served as a first line treatment for ADHD and associated developmental disorders since 1961....
Prescription psychostimulants, such as methylphenidate (MPH), have served as a first line treatment for ADHD and associated developmental disorders since 1961. Psychostimulants has been shown to improve attention, response inhibition, and reduce hyperactivity in patients with ADHD, as well as in non-clinical human populations and animals. While there is a considerable amount of preclinical research investigating the effects of stimulant medications on reward sensitivity and basic learning in male rats, less is understood about their effects in females. Further, there are competing theories on the long-term cognitive impact of MPH, specifically in children who do not have ADHD. To this end, Long-Evans female and male rats were exposed to methylphenidate (0, 2.5, 5 mg/kg, BID, IP) for 20 days during early development (PD10-29). After discontinuation of MPH into adulthood, rats (beginning PD 60) were trained and tested for risk-preference using a 2-choice probabilistic discounting task. For this task, rats were given an option between a 'large-risky' choice (3 sugar pellets delivered on a probabilistic VR schedule) and 'small-certain' choice (1 sugar pellet delivered on a FR schedule). Rats were subsequently tested on an open field conflict test. The results demonstrate that prepubertal exposure to MPH can have lasting effects on decision-making. Specifically, female rats treated with 2.5 mg/kg MPH displayed a decrease in preference for the risky option, whereas male rats treated with the same dose showed an overall increase in preference compared to sex-matched controls. Irrespective of sex, rats treated with 2.5 mg/kg MPH also demonstrated a decrease in anxiety/inhibitory behavior on the modified open field test compared to controls. These results were not due to differences in locomotor behavior. Overall, the study contributes to the growing body of evidence to suggest that MPH exposure early in development can have a sex-dependent impact on decision-making in adulthood.
Topics: Adult; Animals; Central Nervous System Stimulants; Child; Female; Humans; Male; Methylphenidate; Rats; Rats, Long-Evans; Sex Characteristics; Sugars
PubMed: 35780911
DOI: 10.1016/j.pbb.2022.173424