Associations between specialized dementia care, COVID-19 and central nervous system medication use in assisted living: a population-based repeated cross-sectional study.

BACKGROUND: Assisted living (AL) is an increasingly common residential setting for persons with dementia; yet concerns exist about sub-optimal care of this population in AL given its lower levels of staffing and services. Our objectives were to (i) examine associations between AL setting (dementia care vs. other), COVID-19 pandemic waves, and prevalent antipsychotic, antidepressant, anti-dementia, benzodiazepine, and anticonvulsant drug use among residents with dementia/cognitive impairment, and (ii) explore associations between resident and home characteristics and prevalent medication use. METHODS: We conducted a population-based, repeated cross-sectional study using linked clinical and health administrative databases for all publicly funded AL homes in Alberta, Canada, examined between January 2018 - December 2021. The quarterly proportion of residents dispensed a study medication was examined for each setting and period (pandemic vs. comparable historical [2018/2019 combined]) focusing on four pandemic waves (March-May 2020, September 2020-February 2021, March-May 2021, September-December 2021). Log-binomial GEE models estimated prevalence ratios (PR) for period (pandemic vs. historical periods), setting (dementia care vs. other) and period-setting interactions, adjusting for resident (age, sex) and home (COVID-19 cases, health region, ownership) characteristics. RESULTS: On March 1, 2020, there were 2,779 dementia care and 3,013 other AL residents (mean age 83, 69% female) with dementia/cognitive impairment. Antipsychotic use increased during waves 2-4 in both settings, but this was more pronounced in dementia care than other AL during waves 3 and 4 (e.g., adjusted [adj]PR 1.20, 95% CI 1.14-1.27 vs. adjPR 1.09, 95% CI 1.02-1.17, interaction p = 0.023, wave 3). Both settings showed a statistically significant but modest increase in antidepressant use and decrease in benzodiazepine use. For dementia care AL residents only, there was a statistically significant increase in gabapentinoid use during several waves (e.g., adjPR 1.32, 95% CI 1.10-1.59, wave 3). Other than a modest decrease in prevalent anti-dementia drug use for both settings in wave 2, no other significant pandemic effects were observed. CONCLUSIONS: The persistence of the pandemic-associated increase in antipsychotic and antidepressant use in AL residents coupled with a greater increase in antipsychotic and gabapentinoid use for dementia care settings raises concerns about the attendant risks for residents with cognitive impairment.

Reducing Central Nervous System-Active Medications to Prevent Falls and Injuries Among Older Adults: A Cluster Randomized Clinical Trial.

Importance: High-risk medications that contribute to adverse health outcomes are frequently prescribed to older adults. Deprescribing interventions reduce their use, but studies are often not designed to examine effects on patient-relevant health outcomes. Objective: To test the effect of a health system-embedded deprescribing intervention targeting older adults and their primary care clinicians for reducing the use of central nervous system-active drugs and preventing medically treated falls. Design, Setting, and Participants: In this cluster randomized, parallel-group, clinical trial, 18 primary care practices from an integrated health care delivery system in Washington state were recruited from April 1, 2021, to June 16, 2022, to participate, along with their eligible patients. Randomization occurred at the clinic level. Patients were community-dwelling adults aged 60 years or older, prescribed at least 1 medication from any of 5 targeted medication classes (opioids, sedative-hypnotics, skeletal muscle relaxants, tricyclic antidepressants, and first-generation antihistamines) for at least 3 consecutive months. Intervention: Patient education and clinician decision support. Control arm participants received usual care. Main Outcomes and Measures: The primary outcome was medically treated falls. Secondary outcomes included medication discontinuation, sustained medication discontinuation, and dose reduction of any and each target medication. Serious adverse drug withdrawal events involving opioids or sedative-hypnotics were the main safety outcome. Analyses were conducted using intent-to-treat analysis. Results: Among 2367 patient participants (mean [SD] age, 70.6 [7.6] years; 1488 women [63%]), the adjusted cumulative incidence rate of a first medically treated fall at 18 months was 0.33 (95% CI, 0.29-0.37) in the intervention group and 0.30 (95% CI, 0.27-0.34) in the usual care group (estimated adjusted hazard ratio, 1.11 (95% CI, 0.94-1.31) (P = .11). There were significant differences favoring the intervention group in discontinuation, sustained discontinuation, and dose reduction of tricyclic antidepressants at 6 months (discontinuation adjusted rate: intervention group, 0.23 [95% CI, 0.18-0.28] vs usual care group, 0.13 [95% CI, 0.09-0.17]; adjusted relative risk, 1.79 [95% CI, 1.29-2.50]; P = .001) and secondary time points (9, 12, and 15 months). Conclusions and Relevance: In this randomized clinical trial of a health system-embedded deprescribing intervention targeting community-dwelling older adults prescribed central nervous system-active medications and their primary care clinicians, the intervention was no more effective than usual care in reducing medically treated falls. For health systems that attend to deprescribing as part of routine clinical practice, additional interventions may confer modest benefits on prescribing without a measurable effect on clinical outcomes. Trial Registration: ClinicalTrials.gov Identifier: NCT05689554.

Neonatal therapy after maternal central neurotropic drug exposure-a retrospective cohort study.

OBJECTIVE: Evaluation of neonatal morbidity after maternal central neurotropic drug exposure. METHODS: Retrospective single-center level-III neonatology cohort analysis of neonates after CND from 2018 to 2021. Control group of neonates born to mothers without CND cared for at the maternity ward. RESULTS: Significantly more frequent therapy need of neonates with CND [OR 23 (95% CI: 7.8-62); RR 14 (95% CI: 5.4-37); p < 0.01]. Neonates after CND had lower Apgar-scores LM 1 [CND 8.1; CG 8.6; p < 0.05]; LM 5 [CND 9; CG 9.7; p < 0.01]; LM 10 [CND 9.6; CG 9.9; p < 0.05]. The first symptom occurred in 95.35% within 24 h (mean: 3.3 h). CND group showed significantly more often preterm delivery [OR 3.5; RR 3.2; p < 0.05], and especially cumulative multiple symptoms [OR 9.4; RR 6.6; p < 0.01] but no correlation to multiple maternal medication use (p = 0.3). CONCLUSIONS: Neonates exposed to CND are at increased risk for postnatal therapy, often due to multiple symptoms. Neonates should be continuously monitored for at least 24 h.

Factors influencing central nervous system medication deprescribing and behavior change in hospitalized older adults.

BACKGROUND: Central nervous system (CNS) medications are linked to higher morbidity and mortality in older adults. Hospitalization allows for deprescribing opportunities. This qualitative study investigates clinician and patient perspectives on CNS medication deprescribing during hospitalization using a behavioral change framework, aiming to inform interventions and identify recommendations to enhance hospital deprescribing processes. METHODS: This qualitative study focused on hospitalists, primary care providers, pharmacists, and patients aged ≥60 years hospitalized on a general medicine service and prescribed ≥1 CNS medications. Using semi-structured interviews and focus groups, we aimed to evaluate patient medication knowledge, prior deprescribing experiences, and decision-making preferences, as well as provider processes and tools for medication evaluation and deprescribing. Rapid qualitative analysis applying the Capability, Opportunity, Motivation, and Behavior (COM-B) framework revealed themes influencing deprescribing behavior in patients and providers. RESULTS: A total of 52 participants (20 patients and 32 providers) identified facilitators and barriers across deprescribing steps and generated recommended strategies to address them. Clinicians and patients highlighted the opportunity for CNS medication deprescribing during hospitalizations, facilitated by multidisciplinary teams enhancing clinicians' capability to make medication changes. Both groups also stressed the importance of intensive patient engagement, education, and monitoring during hospitalizations, acknowledging challenges in timing and extent of deprescribing, with some patients preferring decisions deferred to outpatient clinicians. Hospitalist and pharmacist recommendations centered on early pharmacist involvement for medication reconciliation, expanding pharmacy consultation and clinician education on deprescribing, whereas patients recommended enhancing shared decision-making through patient education on medication adverse effects, tapering plans, and alternatives. Hospitalists and PCPs also emphasized standardized discharge instructions and transitional care calls to improve medication review and feedback during care transitions. CONCLUSIONS: Clinicians and patients highlighted the potential advantages of hospital interventions for CNS medication deprescribing, emphasizing the necessity of addressing communication, education, and coordination challenges between inpatient and outpatient settings.

Improving drug delivery to the brain: the prodrug approach.

INTRODUCTION: The prodrug approach has been thought to be a simple solution to improve brain drug delivery for decades. Nevertheless, it still comes as a surprise that there is relatively little success in the field. The best example anti-parkinsonian drug levodopa has been serendipitously discovered to be a transporter-utilizing brain-delivered prodrug rather than a rationally developed one. AREAS COVERED: The lack of success can mainly be explained by the insufficient understanding of the role of membrane proteins that can facilitate drug delivery at dynamic barriers, such as the blood-brain barrier (BBB), but also by the sparse knowledge of prodrug bioconverting enzymes in the brain. This review summarizes the current status of the prodrug attempts that have been developed in the past to improve brain drug delivery. EXPERT OPINION: With the expandingly improved analytical and computational technologies, it is anticipated that enhanced brain drug delivery will be eventually achieved for most of the central nervous system (CNS) acting drugs. However, this requires that carrier-mediated (pro)drug delivery methods are implemented in the very early phases of the drug development processes and not as a last step to survive a problematic investigational drug candidate.

Central Nervous System Medications: Pharmacokinetic and Pharmacodynamic Considerations for Older Adults.

Most drugs have not been evaluated in the older population. Recognizing physiological alterations associated with changes in drug disposition and with the ultimate effect, especially in central nervous system-acting drugs, is fundamental. While considering pharmacokinetics, it should be noted that the absorption of most drugs from the gastrointestinal tract does not change in advanced age. There are only few data about the effect of age on the transdermal absorption of medications such as fentanyl. Absorption from an intramuscular injection may be similar in older adults as in younger patients. The distribution of lipophilic drugs (such as diazepam) is increased owing to a relative increase in the percentage of body fat, causing drug accumulation and prolonged drug elimination following cessation. Phase I drug biotransformation is variably decreased in aging, impacting elimination, and hepatic drug clearance has been shown to decrease in older individuals by 10-40% for most drugs studied. Lower doses of phenothiazines, butyrophenones, atypical antipsychotics, antidepressants (citalopram, mirtazapine, and tricyclic antidepressants), and benzodiazepines (such as diazepam) achieve the same extent of exposure. For renally cleared drugs with no prior metabolism (such as gabapentin), the glomerular filtration rate appropriately estimates drug clearance. Important pharmacodynamic changes in older adults include an increased sedative effect of benzodiazepines at a given drug exposure, and a higher sensitivity to mu opiate receptor agonists and to opioid adverse effects. Artificial intelligence, physiologically based pharmacokinetic modeling and simulation, and concentration-effect modeling enabling a differentiation between the pharmacokinetic and the pharmacodynamic effects of aging might help to close some of the gaps in knowledge.

CNSMolGen: A Bidirectional Recurrent Neural Network-Based Generative Model for De Novo Central Nervous System Drug Design.

Central nervous system (CNS) drugs have had a significant impact on treating a wide range of neurodegenerative and psychiatric disorders. In recent years, deep learning-based generative models have shown great potential for accelerating drug discovery and improving efficacy. However, specific applications of these techniques in CNS drug discovery have not been widely reported. In this study, we developed the CNSMolGen model, which uses a framework of bidirectional recurrent neural networks (Bi-RNNs) for de novo molecular design of CNS drugs. Results showed that the pretrained model was able to generate more than 90% of completely new molecular structures, which possessed the properties of CNS drug molecules and were synthesizable. In addition, transfer learning was performed on small data sets with specific biological activities to evaluate the potential application of the model for CNS drug optimization. Here, we used drugs against the classical CNS disease target serotonin transporter (SERT) as a fine-tuned data set and generated a focused database against the target protein. The potential biological activities of the generated molecules were verified by using the physics-based induced-fit docking study. The success of this model demonstrates its potential in CNS drug design and optimization, which provides a new impetus for future CNS drug development.

Central nervous system medication use around hospitalization.

BACKGROUND: Central nervous system (CNS) medication use is common among older adults, yet the impact of hospitalizations on use remains unclear. This study details CNS medication use, discontinuations, and user profiles during hospitalization periods. METHODS: Retrospective cohort study using electronic health records on patients ≥65 years, from three hospitals (2018-2020), and prescribed a CNS medication around hospitalization (90 days prior to 90 days after). Latent class transitions analysis (LCTA) examined profiles of CNS medication class users across four time points (90 days prior, admission, discharge, 90 days after hospitalization). RESULTS: Among 4666 patients (mean age 74.3 ± 9.3 years; 63% female; 70% White; mean length of stay 4.6 ± 5.6 days (median 3.0 [2.0, 6.0]), the most commonly prescribed CNS medications were antidepressants (56%) and opioids (49%). Overall, 74% (n = 3446) of patients were persistent users of a CNS medication across all four time points; 7% (n = 388) had discontinuations during hospitalization, but of these, 64% (216/388) had new starts or restarts within 90 days after hospitalization. LCTA identified three profile groups: (1) low CNS medication users, 54%-60% of patients; (2) mental health medication users, 30%-36%; and (3) acute/chronic pain medication users, 9%-10%. Probability of staying in same group across the four time points was high (0.88-1.00). Transitioning to the low CNS medication use group was highest from admission to discharge (probability of 9% for pain medication users, 5% for mental health medication users). Female gender increased (OR 2.4, 95% CI 1.3-4.3), while chronic kidney disease lowered (OR 0.5, 0.2-0.9) the odds of transitioning to the low CNS medication use profile between admission and discharge. CONCLUSIONS: CNS medication use stays consistent around hospitalization, with discontinuation more likely between admission and discharge, especially among pain medication users. Further research on patient outcomes is needed to understand the benefits and harms of hospital deprescribing, particularly for medications requiring gradual tapering.

Diagnoses and Treatment of Behavioral and Psychological Symptoms of Dementia Among Racially and Ethnically Diverse Persons Living with Dementia.

Background: Behavioral and psychological symptoms of dementia (BPSD) and prescribed central nervous system (CNS) active drugs to treat them are prevalent among persons living with Alzheimer's disease and related dementias (PLWD) and lead to negative outcomes for PLWD and their caregivers. Yet, little is known about racial/ethnic disparities in diagnosis and use of drugs to treat BPSD. Objective: Quantify racial/ethnic disparities in BPSD diagnoses and CNS-active drug use among community-dwelling PLWD. Methods: We used a retrospective cohort of community-dwelling Medicare Fee-for-Service beneficiaries with dementia, continuously enrolled in Parts A, B and D, 2017-2019. Multivariate logistic models estimated rates of BPSD diagnosis and, conditional on diagnosis, CNS-active drug use. Results: Among PLWD, 67.1% had diagnoses of an affective, psychosis or hyperactivity symptom. White (68.3%) and Hispanic (63.9%) PLWD were most likely, Blacks (56.6%) and Asians (52.7%) least likely, to have diagnoses. Among PLWD with BPSD diagnoses, 78.6% took a CNS-active drug. Use was highest among whites (79.3%) and Hispanics (76.2%) and lowest among Blacks (70.8%) and Asians (69.3%). Racial/ethnic differences in affective disorders were pronounced, 56.8% of white PLWD diagnosed; Asians had the lowest rates (37.8%). Similar differences were found in use of antidepressants. Conclusions: BPSD diagnoses and CNS-active drug use were common in our study. Lower rates of BPSD diagnoses in non-white compared to white populations may indicate underdiagnosis in clinical settings of treatable conditions. Clinicians' review of prescriptions in this population to reduce poor outcomes is important as is informing care partners on the risks/benefits of using CNS-active drugs.

Machine Learning Exploration of the Relationship Between Drugs and the Blood-Brain Barrier: Guiding Molecular Modification.

OBJECTIVE: This study aimed to improve the efficiency of pharmacotherapy for CNS diseases by optimizing the ability of drug molecules to penetrate the Blood-Brain Barrier (BBB). METHODS: We established qualitative and quantitative databases of the ADME properties of drugs and derived characteristic features of compounds with efficient BBB penetration. Using these insights, we developed four machine learning models to predict a drug's BBB permeability by assessing ADME properties and molecular topology. We then validated the models using the B3DB database. For acyclovir and ceftriaxone, we modified the Hydrogen Bond Donors and Acceptors, and evaluated the BBB permeability using the predictive model. RESULTS: The machine learning models performed well in predicting BBB permeability on both internal and external validation sets. Reducing the number of Hydrogen Bond Donors and Acceptors generally improves BBB permeability. Modification only enhanced BBB penetration in the case of acyclovir and not ceftriaxone. CONCLUSIONS: The machine learning models developed can accurately predict BBB permeability, and many drug molecules are likely to have increased BBB penetration if the number of Hydrogen Bond Donors and Acceptors are reduced. These findings suggest that molecular modifications can enhance the efficacy of CNS drugs and provide practical strategies for drug design and development. This is particularly relevant for improving drug penetration of the BBB.

Occurrence, ecotoxicity and ecological risks of psychoactive substances in surface waters.

Psychoactive substances (PSs) represent a subset of emerging contaminants. Their widespread production and utilization contribute to a growing ecological burden and risk on a global scale. Conventional wastewater treatment methods have proven insufficient in adequately removing psychoactive substances, leading to their occurrence in surface water ecosystems worldwide. As of present, however, a thorough understanding of their geographical prevalence and distribution patterns remains elusive. Further, in the existing literature, there is a scarcity of comprehensive overviews that systematically summarize the toxicity of various psychoactive substances towards aquatic organisms. Through summarizing almost 140 articles, the present study provides an overview of the sources, pollution status, and biotoxicity of psychoactive substances in surface waters, as well as an assessment of their ecological risks. Concentrations of several psychoactive substances in surface waters were found to be as high as hundreds or even thousands of ng·L-1. In parallel, accumulation of psychoactive substances in the tissues or organs of aquatic organisms was found to potentially cause certain adverse effects, including behavioral disorders, organ damage, and DNA changes. Oxidative stress was found to be a significant factor in the toxic effects of psychoactive substances on organisms. The application of the risk quotient approach indicated that psychoactive substances posed a medium to high risk in certain surface water bodies, as well as the need for sustained long-term attention and management strategies.

NPS-EQA PART II: Four years' experience in external quality assessment program in Italy for classical and new psychoactive substances analysis in hair.

In 2019, the Italian National Institute of Health established an external quality assessment (EQA) program to evaluate the performance of laboratories of collaborative centres participating in the National Early Warning System in hair testing for classical and new psychoactive substances (NPS). The results obtained in the four rounds (2019-2023) and the evolution in hair testing performance for classic drugs of abuse and new psychoactive substances are presented. A total of 11 hair specimens, including 3 blank samples, were prepared by adding different classes of classical and NPS at known concentrations to pre-screened drug-free hair. False negative and false positive results were calculated for the qualitative data evaluation. The quantitative evaluation included the imprecision (as % coefficient of variation, CV%) and the accuracy (as % error, ERR%) of the results with respect to a mean value obtained by reference laboratories and Z-score values were assessed. Over the years, an improvement in false negative results (from 52.4% in the first year to 34.3% in the last one) and false positive results (from 55.0% in the first year to 30.8.% in the last one) was observed. In the first round, the mean ERR% ranged from 6.2% to 112.8% due to NPS determination. However, in the subsequent three rounds, the mean ERR% ranged from 10.4% to 22.4%, The mean CV% in the four rounds was approximately 41.5% (ranging from 44.3% to 53.3%). Between 12.0% and 56.6% of the reported results in all rounds should be considered satisfactory. EQA programs help laboratories to identify and correct problems within their processes by highlighting errors and variations. This ensures that the results produced are accurate and reproducible.

NPS-EQA PART I: Four years' experience in external quality assessment program in Italy for classical and new psychoactive substances analysis in oral fluid.

In 2019, Italian National Institute of Health established an external quality assessment program (EQA) to evaluate the performance of oral fluid testing for classical and new psychoactive substances by laboratories participating in the National Early Warning System collaborative centres. This report presents the results of four rounds between 2019 and 2023. Eleven oral fluid specimens, including 3 blank samples, were prepared by adding different classes of and new psychoactive drugs at known concentrations to pre-screened drug-free oral fluid. False-negative and false-positive results were calculated for the qualitative data evaluation. The quantitative evaluation measured the imprecision and accuracy of the results, in terms of coefficient of variation (CV%) and percent error (ERR%), respectively, with respect to a mean value obtained by reference laboratories. Z-score values were then calculated. Over the years, there has been a significant improvement in false-negative results (from 42.7% in the first year to 19.4% in the last year), but not in false-positive results (from 33.3% in the first year to 22.2% in the last one). In addition to the classic drugs of abuse (e.g. cocaine, amphetamine, methadone), the substances found in false positive samples belonged to the class of synthetic cannabinoids (e.g 5-fluoro CUMYL-PINACA and 5-fluoro-EDMB-PICA), synthetic opioids (e.g butyrylfentanyl) and tryptamines (e.g. 5-methoxy-N-methyl-N-isopropyltryptamine). The four rounds yielded a mean ERR% of approximately 22.1% and a mean CV% of around 41.5%. The participating laboratories demonstrated variable performances in relation to the class of analysed psychoactive substances, as evidenced by the calculated Z-scores. Between 25% and 60% of the reported results in all rounds should be considered satisfactory. EQA is a crucial element of laboratory quality management systems. It promotes continuous improvement and maintains high standards in the field of forensic and clinical drug testing.

Development of a multidisciplinary medication management program in nursing homes: protocol for a randomized controlled trial : Multidisciplinary medication management in nursing homes.

BACKGROUND: Polypharmacy and the use of potentially inappropriate medications are common among nursing home residents and are associated with negative outcomes. Although deprescribing has been proposed as a way to curtail these problems, the best way to implement multidisciplinary comprehensive medication review and deprescribing and its real impact in specific high-risk populations, such as nursing home residents, is still unclear. This multicenter randomized controlled clinical trial aims to assess the effects of a multidisciplinary mediation management program on medication use and health problems. METHODS: A total of 1,672 residents aged ≥ 65 years from 22 nursing homes in South Korea who meet the targeted criteria, such as the use of ≥ 10 medications, are eligible to participate. The experimental group will receive a comprehensive medication review, deprescription, and multidisciplinary case conference with the help of platform. Outcomes will be measured at baseline, at the end of the intervention, as well as at 3, 6, 9, and 12 months after the end of the intervention. The primary endpoints will be the rate of adverse drug events, number of potentially inappropriate medications/potentially inappropriate medication users/two or more central nervous system drug/ central nervous system drug users, delirium, emergency department visits, hospitalization, and falls. The secondary endpoint will be the number of medications taken and polypharmacy users. DISCUSSION: Our trial design is unique in that it aims to introduce a structured operationalized clinical program focused on reducing polypharmacy and potentially inappropriate medications in a nursing home setting with large samples. TRIAL REGISTRATION: Ethical approval was granted by the public institutional review board of the Ministry of Health and Welfare (2022-1092-009). The study is also registered with the Clinical Research Information Service (Identifier: KCT0008157, Development and evaluation of a multidisciplinary medication management program in long-term care facility residents Status: Approved First Submitted Date: 2023/01/18 Registered Date: 2023/02/03 Last Updated Date: 2023/01/18 (nih.go.kr) https://cris.nih.go.kr/ ), which includes all items from the World Health Organization Trial Registration Dataset.

2-Phenylcyclopropylmethylamine (PCPMA) as a privileged scaffold for central nervous system drug design.

The use of privileged scaffolds in medicinal chemistry is an effective way to accelerate the drug discovery process, especially at the hit/lead optimization stage. 2-Phenylcyclopropylmethylamine (PCPMA) is a less commonly used chemical scaffold in medicinal chemistry, but many PCPMA-containing compounds exert therapeutic effects for various diseases, in particular central nervous system (CNS) diseases such as depression, schizophrenia, sleep disorder, and Parkinson's disease. The backbone of the PCPMA scaffold enables a unique structure of an amino group linked to a benzene ring through an alkyl linker, making it a useful template for the design of bioactive compounds especially for CNS drug targets including aminergic GPCRs and transporters. This review summarizes the medicinal chemistry studies of PCPMA-containing drugs and drug-like molecules, their mechanisms of action, and biological activities. We conclude that PCPMA is a unique and useful privileged scaffold for CNS drug design.

Blood-brain barrier transporters: a translational consideration for CNS delivery of neurotherapeutics.

INTRODUCTION: Successful neuropharmacology requires optimization of CNS drug delivery and, by extension, free drug concentrations at brain molecular targets. Detailed assessment of blood-brain barrier (BBB) physiological characteristics is necessary to achieve this goal. The 'next frontier' in CNS drug delivery is targeting BBB uptake transporters, an approach that requires evaluation of brain endothelial cell transport processes so that effective drug accumulation and improved therapeutic efficacy can occur. AREAS COVERED: BBB permeability of drugs is governed by tight junction protein complexes (i.e., physical barrier) and transporters/enzymes (i.e., biochemical barrier). For most therapeutics, a component of blood-to-brain transport involves passive transcellular diffusion. Small molecule drugs that do not possess acceptable physicochemical characteristics for passive permeability may utilize putative membrane transporters for CNS uptake. While both uptake and efflux transport mechanisms are expressed at the brain microvascular endothelium, uptake transporters can be targeted for optimization of brain drug delivery and improved treatment of neurological disease states. EXPERT OPINION: Uptake transporters represent a unique opportunity to optimize brain drug delivery by leveraging the endogenous biology of the BBB. A rigorous understanding of these transporters is required to improve translation from the bench to clinical trials and stimulate the development of new treatment paradigms for neurological diseases.

Trial of N-Acetyl-l-Leucine in Niemann-Pick Disease Type C.

BACKGROUND: Niemann-Pick disease type C is a rare lysosomal storage disorder. We evaluated the safety and efficacy of N-acetyl-l-leucine (NALL), an agent that potentially ameliorates lysosomal and metabolic dysfunction, for the treatment of Niemann-Pick disease type C. METHODS: In this double-blind, placebo-controlled, crossover trial, we randomly assigned patients 4 years of age or older with genetically confirmed Niemann-Pick disease type C in a 1:1 ratio to receive NALL for 12 weeks, followed by placebo for 12 weeks, or to receive placebo for 12 weeks, followed by NALL for 12 weeks. NALL or matching placebo was administered orally two to three times per day, with patients 4 to 12 years of age receiving weight-based doses (2 to 4 g per day) and those 13 years of age or older receiving a dose of 4 g per day. The primary end point was the total score on the Scale for the Assessment and Rating of Ataxia (SARA; range, 0 to 40, with lower scores indicating better neurologic status). Secondary end points included scores on the Clinical Global Impression of Improvement, the Spinocerebellar Ataxia Functional Index, and the Modified Disability Rating Scale. Crossover data from the two 12-week periods in each group were included in the comparisons of NALL with placebo. RESULTS: A total of 60 patients 5 to 67 years of age were enrolled. The mean baseline SARA total scores used in the primary analysis were 15.88 before receipt of the first dose of NALL (60 patients) and 15.68 before receipt of the first dose of placebo (59 patients; 1 patient never received placebo). The mean (±SD) change from baseline in the SARA total score was -1.97±2.43 points after 12 weeks of receiving NALL and -0.60±2.39 points after 12 weeks of receiving placebo (least-squares mean difference, -1.28 points; 95% confidence interval, -1.91 to -0.65; P<0.001). The results for the secondary end points were generally supportive of the findings in the primary analysis, but these were not adjusted for multiple comparisons. The incidence of adverse events was similar with NALL and placebo, and no treatment-related serious adverse events occurred. CONCLUSIONS: Among patients with Niemann-Pick disease type C, treatment with NALL for 12 weeks led to better neurologic status than placebo. A longer period is needed to determine the long-term effects of this agent in patients with Niemann-Pick disease type C. (Funded by IntraBio; ClinicalTrials.gov number, NCT05163288; EudraCT number, 2021-005356-10.).