Head-to-Head Comparison of Sedation and Somnolence Among 37 Antipsychotics in Schizophrenia, Bipolar Disorder, Major Depression, Autism Spectrum Disorders, Delirium, and Repurposed in COVID-19, Infectious Diseases, and Oncology From the FAERS, 2004-2020.

Objective: Antipsychotic compounds are known to induce sedation somnolence and have expanded clinical indications beyond schizophrenia to regulatory approval in bipolar disorder, treatment-resistant depression, and is being repurposed in infectious diseases and oncology. However, the medical sciences literature lacks a comprehensive association between sedation and somnolence among a wide-range of antipsychotic compounds. The objective of this study is to assess the disproportionality of sedation and somnolence among thirty-seven typical and atypical antipsychotics. Materials and Methods: Patient adverse drug reactions (ADR) cases were obtained from the United States Food and Drug Administration Adverse Events Reporting System (FAERS) between January 01, 2004 and September 30, 2020 for a wide-array of clinical indications and off-label use of antipsychotics. An assessment of disproportionality were based on cases of sedation and somnolence and calculated using the case/non-case methodology. Statistical analysis resulting in the reporting odds-ratio (ROR) with corresponding 95% confidence intervals (95% CI) were conducted using the R statistical programming language. Results: Throughout the reporting period, there were a total of 9,373,236 cases with 99,251 specific ADRs reporting sedation and somnolence. Zuclopenthixol (n = 224) ROR = 13.3 (95% CI, 11.6-15.3) was most strongly associated of sedation and somnolence and haloperidol decanoate long-acting injection (LAI) was not statistically associated sedation and somnolence. Further, among atypical antipsychotic compounds, tiapride and asenapine were the top two compounds most strongly associated with sedation and somnolence. Comprehensively, the typical antipsychotics ROR = 5.05 (95%CI, 4.97-5.12) had a stronger association with sedation and somnolence when compared to atypical antipsychotics ROR = 4.65 (95%CI, 4.47-4.84). Conclusion: We conducted a head-to-head comparison of thirty-seven antipsychotics and ranked the compounds based on the association of sedation and somnolence from ADR data collected throughout 16 years from the FAERS. The results are informative and with recent interests in repurposing phenothiazine antipsychotics in infectious disease and oncology provides an informative assessment of the compounds during repurposing and in psychopharmacology.

Fluoxetine pharmacokinetics and tissue distribution quantitatively supports a therapeutic role in COVID-19 at a minimum dose of 20 mg per day.

Background.  Recent in vitro studies have shown fluoxetine inhibits the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pathogen, including variants B.1.1.7 and B.1.351, SARS-CoV-2 spike mutations (E484K, K417N, N501Y), and one retrospective clinical study reported fluoxetine exposure at a median dose of 20 mg in patients with the SARS-CoV-2 coronavirus disease 2019 (COVID-19) had a significantly lower risk of intubation and death. The aim of this study is to conduct in silico population pharmacokinetic dosing simulations to quantify the percentage of patients achieving a trough level for the effective concentration resulting in 90% inhibition (EC90) of SARS-CoV-2 as reported in Calu-3 human lung cells.  Methods.  Population pharmacokinetic parameter estimates for a structural one-compartment model with first-order absorption were used to simulate fluoxetine pharmacokinetic data. A population of 1,000 individuals were simulated at standard fluoxetine doses (20 mg/day, 40 mg/day, and 60 mg/day) to estimate the percentage of the patients achieving a trough plasma level for the EC90 SARS-CoV-2 inhibitory concentration for a 10 day treatment period. All analyses were conducted via statistical programming in R.  Results.  Standard fluoxetine antidepressant doses resulted in a range of 81% to 97% of the patient population achieving a trough target plasma concentration of 23.2 ng/ml at day 10 and translates to a lung-tissue distribution coefficient of 60-times higher (EC90 of 4.02 mM). At a dose of 40 mg per day, at least 87% of patients will reach the trough target EC90 concentration within three days.   Conclusion. Overall, the findings of this population pharmacokinetic dosing study corroborates in vitro and observational clinical studies reporting the first selective serotonin reuptake inhibitor fluoxetine inhibits the SARS-CoV-2 pathogen at commonly treated doses in the practice of psychiatry.

Association of sleep among 30 antidepressants: a population-wide adverse drug reaction study, 2004-2019.

BACKGROUND: Sleep is one of the most essential processes required to maintain a healthy human life, and patients experiencing psychiatric illness often experience an inability to sleep. The aim of this study is to test the hypothesis that antidepressant compounds with strong binding affinities for the serotonin 5-HT2C receptor, histamine H1 receptors, or norepinephrine transporter (NET) will be associated with the highest odds of somnolence. METHODS: Post-marketing cases of patient adverse drug reactions were obtained from the United States Food and Drug Administration Adverse Events Reporting System (FAERS) during the reporting window of January 2004 to September 2019. Disproportionality analyses of antidepressants reporting somnolence were calculated using the case/non-case method. The reporting odds-ratios (ROR) and corresponding 95% confidence interval (95% CI) were computed and all computations and graphing conducted in R. RESULTS: There were a total of 69,196 reported cases of somnolence out of a total of 7,366,864 cases reported from January 2004 to September 2019. Among the 30 antidepressants assessed, amoxapine (n = 16) reporting odds-ratio (ROR) = 7.1 (95% confidence interval [CI] [4.3-11.7]), atomoxetine (n = 1,079) ROR = 6.6 (95% CI [6.2-7.1]), a compound generally approved for attention deficit hyperactivity disorder (ADHD), and maprotiline (n = 18) ROR = 6.3 (95% CI, 3.9-10.1) were the top three compounds ranked with the highest reporting odds of somnolence. In contrast, vortioxetine (n = 52) ROR = 1.3 (95% CI [1.0-1.8]), milnacipran (n = 58) ROR = 2.1 (95% CI [1.7-2.8]), and bupropion (n = 1,048) ROR = 2.2 (95% CI [2.1-2.4]) are least significantly associated with somnolence. Moreover, levomilnacipran (n = 1) ROR = 0.4 (95% CI [0.1-2.9]) was not associated with somnolence. CONCLUSION: Among the thirty tested antidepressants, consistent with the original hypothesis, amoxepine has strongest 5-HT2C receptor binding affinity and has the highest reporting odds of somnolence. Atomoxetine, ranked second in reporting odds of somnolence overall, binds to the NET with with the strongest binding affinity among the thirty compounds. Mirtazapine, a tetracyclic antidepressant, was ranked 11th in reporting odds of somnolence and had the strongest H1 receptor binding affinity. This study provides an informative ranking of somnolence among thirty antidepressant compounds with an already wide array of clinical indications as well as provides insight into potential drug repurposing in psychopharmacology.

Dual Roles for the TSPYL Family in Mediating Serotonin Transport and the Metabolism of Selective Serotonin Reuptake Inhibitors in Patients with Major Depressive Disorder.

We previously reported that testis-specific Y-encoded-like protein (TSPYLs) are transcription regulators for CYP3A4, CYP2C9, and CYP2C19. Here, we observed dual roles for TSPYLs in mediating serotonin transport and the metabolism of selective serotonin reuptake inhibitors (SSRIs) in patients with major depressive disorder (MDD). The widely prescribed SSRIs, citalopram, and escitalopram are metabolized mainly by CYP2C19. The TSPYL1 rs3828743 single nucleotide polymorphism (SNP), which decreases its suppression of CYP2C19 expression, was associated with rapid escitalopram metabolism and worse treatment response in the Mayo PGRN-AMPS clinical trial. We also found that TSPYLs can regulate expression of the serotonin transporter protein, SLC6A4, and, in turn, serotonin transport into cells. The SNPs in tight linkage disequilibrium with the TSPYL1 rs10223646 SNP were significantly correlated with baseline severity of depression in patients with MDD in the Sequenced Treatment Alternatives to Relieve Depression and International SSRI Pharmacogenomics Consortium clinical trials. Our findings suggest that genetic variation in TSPYL genes may be novel indicators for baseline severity of depression and SSRI poor response.

Optimizing drug selection in psychopharmacology based on 40 significant CYP2C19- and CYP2D6-biased adverse drug reactions of selective serotonin reuptake inhibitors.

BACKGROUND: Selective serotonin reuptake inhibitors (SSRIs) are among the most widely prescribed class of drugs in the practice of psychiatry. Cytochrome P450 (CYP) 2C19 and CYP2D6 are established as clinically relevant drug metabolizing enzymes (DMEs) that influence the pharmacokinetics of SSRIs and may either be grouped as being primarily metabolized by CYP2C19 or CYP2D6. The aim of this study is to test the hypothesis that the primary drug metabolizing pathway for SSRI antidepressants are associated with adverse drug reactions (ADRs) related to physiological modulation of organs with the highest gene tissue expression. METHODS: Post-marketing ADR cases were obtained from the United States Food and Drug Administration's Adverse Events Reporting System from each of the four quarters for the years 2016 and 2017. Cases were grouped based on one of two primary pharmacokinetic pharmacogenomic pathway biomarkers CYP2C19 and CYP2D6. Citalopram, escitalopram, and sertraline were grouped as CYP2C19 substrates and fluvoxamine, fluoxetine, and paroxetine as CYP2D6 substrates. Logistic regression was computed for the reported SSRI ADRs associated with one of two aforementioned DMEs. All data homogenization and computations were performed in R for statistical programming. RESULTS: The most commonly reported ADR among the SSRIs was anxiety (n = 3,332). The top two ADRs associated with SSRIs metabolized by CYP2D6 are: nightmare (n = 983) reporting odds-ratio (OR) = 4.37 (95% confidence interval (CI) [3.67-5.20]) and panic attack (n = 1,243) OR = 2.43 (95% CI [2.11-2.79]). Contrastingly, the top two ADRs for CYP2C19 metabolized SSRIs are: electrocardiogram QT prolonged (n = 351) OR = 0.18 (95% CI [0.13-0.24]) and small for dates baby (n = 306) OR = 0.19 (95% CI [0.14-0.26]). The study tested and produced 40 statistically significant CYP2C19- and CYP2D6-biased ADRs. In overall context, the results suggest that CYPC19 SSRI substrates are associated with ADRs related to modulation of the autonomic nervous system, seizure, pain, erectile-dysfunction, and absorption. Contrastingly, CYP2D6 SSRI substrates are associated with ADRs related to nightmares, withdrawal syndrome, and de-realization of cognitive processes. The results of this study may aid as guidance to optimize drug selection in psychopharmacology.

Influence of CYP450 Enzymes, CES1, PON1, ABCB1, and P2RY12 Polymorphisms on Clopidogrel Response in Patients Subjected to a Percutaneous Neurointervention.

PURPOSE: Clopidogrel is a thienopyridine prodrug that inhibits platelet aggregation. It is prescribed to prevent atherothrombotic and thromboembolic events in patients receiving a stent implant in carotid, vertebral, or cranial arteries. The influence of cytochrome P-450 (CYP) 2C19 on the response to clopidogrel has been widely studied; however, the effect of other genes involved in clopidogrel absorption and metabolism has not been established in this cohort of patients. METHODS: This observational retrospective study assessed the antiplatelet response and the prevalence of hemorrhagic or ischemic events after percutaneous neurointervention in clopidogrel-treated patients, related to 35 polymorphisms in the genes encoding the clopidogrel-metabolizing enzymes (CYP2C19, CYP1A2, CYP2B6, CYP2C9, CYP2C9, CYP3A4, CYP3A5, carboxylesterase-1 [CES1], and paraoxonase-1 [PON1]), P-glycoprotein transporter (ABCB1), and platelet receptor P2Y12. Polymorphisms were analyzed by quantitative real-time polymerase chain reaction and matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry. Antiplatelet response was documented with the VerifyNow system (Accriva, San Diego, California). FINDINGS: We confirmed that CYP2C19 is the most important enzyme involved in clopidogrel response. The carriage of the CYP2C19*2 allele was strongly associated with hyporesponse to clopidogrel, while the CYP2C19*17 allele was a protective factor for the development of ischemic events (odds ratio = 0.149; P = 0.002) but a risk factor for bleeding (odds ratio = 3.60; P = 0.038). Patients carrying ABCB1 mutated alleles showed lower aggregation values, suggesting that clopidogrel absorption is influenced by P-glycoprotein. In fact, the percentage of responders was significantly higher in the group carrying the mutated haplotype compared to the wild type (80.8% vs 43.3%; P = 0.009). Patients with the CES1 G143E C/T genotype showed a considerably lower, aggregation value versus wild-type patients, although the difference was not significant likely due to the small sample size (59.0 [21.2] vs 165.2 [86.0] PRU; P = 0.084), which suggests an increased active metabolite formation. No relationship was found between polymorphisms in other CYP genes, PON1, or P2RY12 and response to clopidogrel in patients subjected to neurointervention procedures. IMPLICATIONS: Therapeutic guidelines recommend that CYP2C19 intermediate and poor metabolizers with acute coronary syndromes undergoing percutaneous coronary intervention receive an alternative antiplatelet therapy; however, genotype-guided therapy is not a standard recommendation for neurovascular conditions. This is the first study to carry out a joint analysis of CYP2C19 and other genes involved in clopidogrel treatment in patients receiving percutaneous neurointervention. Our findings support routine genotyping in clopidogrel-treated patients. Moreover, we encourage considering an alternative antiplatelet therapy in CYP2C19 intermediate, poor and ultrarapid metabolizers. Additionally, ABCB1 polymorphisms could be considered for a better pharmacogenetic approach.

An opportunity for clinical pharmacology trained physicians to improve patient drug safety: A retrospective analysis of adverse drug reactions in teenagers.

Background: Adverse drug reactions (ADRs) are a major cause of hospital admissions, prolonged hospital stays, morbidity, and drug-related mortality. In this study, we sought to identify the most frequently reported medications and associated side effects in adolescent-aged patients in an effort to prioritize clinical pharmacology consultation efforts for hospitals seeking to improve patient safety.   Methods: Quarterly reported data were obtained from the United States Food and Drug Administration Adverse Events Reporting System (FAERS) from the third quarter of 2014 and ending in the third quarter of 2017. We then used the GeneCards database to map the pharmacogenomic biomarkers associated with the most reported FAERS drugs. Data homogenization and statistics analysis were all conducted in R for statistical programming. Results: We identified risperidone (10.64%) as the compound with the most reported ADRs from all reported cases. Males represented 90.1% of reported risperidone cases with gynecomastia being the most reported ADR. Ibuprofen OR=188 (95% CI, 105.0000 - 335.000) and quetiapine fumarate OR=116 (95% CI, 48.4000 - 278.000) were associated with the highest odds of completed suicide in teenagers. Ondansetron hydrochloride OR=7.12 (95% CI, 1.59 - 31.9) resulted in the highest odds of pneumothorax. Lastly, olanzapine (8.96%) represented the compound with the most reported drug-drug interactions cases, while valproic acid OR=221 (95% CI, 93.9000 - 522.000) was associated with the highest odds of drug-drug interactions. Conclusion: Despite any data limitations, physicians prescribing risperidone in males should be aware of the high rates of adverse drug events and an alternative psychotropic should be considered in male patients. Further, patients with a history of pneumothorax or genetically predisposed to pneumothorax should be considered for an alternative antiemetic to ondansetron hydrochloride, due to increased odds associated with the drug and adverse event.

Predicting lithium treatment response in bipolar patients using gender-specific gene expression biomarkers and machine learning.

Background: We sought to test the hypothesis that transcriptiome-level genes signatures are differentially expressed between male and female bipolar patients, prior to lithium treatment, in a patient cohort who later were clinically classified as lithium treatment responders. Methods: Gene expression study data was obtained from the Lithium Treatment-Moderate dose Use Study data accessed from the National Center for Biotechnology Information's Gene Expression Omnibus via accession number GSE4548. Differential gene expression analysis was conducted using the Linear Models for Microarray and RNA-Seq (limma) package and the Random Forests machine learning algorithm in R. Results: In pre-treatment lithium responders, the following genes were found having a greater than 0.5 fold-change, and differentially expressed indicating a male bias: RBPMS2, SIDT2, CDH23, LILRA5, and KIR2DS5; while the female-biased genes were: HLA-H, RPS23, FHL3, RPL10A, NBPF14, PSTPIP2, FAM117B, CHST7, and ABRACL. Conclusions: Using machine learning, we developed a pre-treatment gender- and gene-expression-based predictive model selective for lithium responders with an ROC AUC of 0.92 for men and an ROC AUC of 1 for women.

Comparison of the vasodilatory effects of sodium nitroprusside vs. nitroglycerin.

The vasodilatory mechanism of Nntroglycerin (NTG) is similar to sodium nitroprusside (SNP) in regard to action on guanosine 3'5'-monophosphate (cyclic GMP) via nitric oxide. However, it is unknown whether NTG can achieve the same magnitude of vasodilation in the forearm as SNP. Therefore, the purpose of the study was to evaluate the differences in forearm blood flow (FBF) and forearm vascular conductance (FVC) during escalating infusions of NTG vs. SNP at similar concentration doses and rates. We measured FBF using venous occlusion plethysmography (VOP) and Doppler ultrasound in eight young, healthy participants (mean age = 28 ± 2 yr) during four forearm volume (FAV)-specific doses (0.25, 0.5, 1, and 2 µg·100 ml FAV-1·min-1) of SNP and NTG infused via a brachial artery catheter. There was a significant difference in FVC of SNP vs. NTG only at the higher doses, as measured by VOP (14.9 ± 1.4 and 18.3 ± 1.5 vs. 11.6 ± 1.2 and 12.5 ± 1.2 ml/dl FAV-1·min-1·100 mmHg-1). FVC as measured by Doppler ultrasound unadjusted for FAV was significantly different at the lowest and the higher two doses of SNP compared with NTG (202.1 ± 25.8, 329.4 ± 46.7, and 408 ± 63.5 vs. 142.9 ± 22.4, 217.2 ± 18.8, and 247.5 ± 18.2 ml·min-1·100 mmHg-1). SNP induces significantly higher vasodilatory actions compared with NTG. However, NTG is comparable in eliciting equivalent vasodilator effects to SNP during low concentration doses when measured by VOP. Importantly, for forearm pharmacology studies, NTG can elicit marked endothelium-independent forearm vasodilation.NEW & NOTEWORTHY We compared the vasodilatory capacities of NTG vs. SNP at similar concentration doses and rates into the forearm. Based on the results of the study, it may be feasible to use intra-arterial NTG as a measure of endothelial-independent vasodilator in research studies. However, NTG dosing may need to be higher if used as an endothelial-independent vasodilator due to significant differences in the vasodilatory effects during higher doses of SNP compared with NTG.

A pharmacodynamic modelling and simulation study identifying gender differences of daily olanzapine dose and dopamine D2-receptor occupancy.

BACKGROUND: Gender differences in treatment response rates for patients treated with antipsychotics are known. However, the literature lacks a pharmacodynamic model to allow for gender-based clinical trial simulations from modelling parameters for Olanzapine and dopamine D2 receptor occupancy. Thus, the primary aim of this analysis is to test and quantify the effect of gender on the pharmacodynamics of Olanzapine. METHODS: Population pharmacodynamic modelling was performed using non-linear mixed effects modelling in MONOLIX, while the Clinical Trial Simulations were performed using R for statistical programming. The pharmacometric analysis is based on a pooled data approach from three clinical studies where patients were diagnosed with schizophrenia and one clinical study where the patients were diagnosed with bipolar disorder. RESULTS: Olanzapine D2RO was modelled using an Emax model in a study population of 70 patients. Population pharmacodynamic parameters were estimated to be: Emax = 85.6% (RSE = 3%), ED50-Men = 5.15 mg/day (RSE = 14) and ED50-Women = 2.38 mg/day (RSE = 34%), with the p-value = 0.037 for the gender-stratified ED50 results. CONCLUSION: The pharmacometrics analysis and model-based dosing simulations suggest that, in order to achieve 70% D2RO, women require a 10 mg/day dose and men require approximately a 20 mg/day dose of Olanzapine. Further, clinical implications exist suggesting that clinicians should factor patient gender when considering both a starting dose, as well a, a maintenance dose for patients prescribed Olanzapine due to quantifiable gender-differences of striatal dopamine D2 receptor occupancy.

CYP2B6 Genotype Guided Dosing of Propofol Anesthesia in the Elderly based on Nonparametric Population Pharmacokinetic Modeling and Simulations.

OBJECTIVE: The primary aim of this article is to test the hypothesis that nonparametric pharmacometric modeling will accurately identify CYP2B6 genotype subgroups based on data from a study that reported results based on parametric pharmacokinetics (PK). METHODS: Propofol concentration-time data were originally reported in the Kansaku et al. 2011 publication. Nonparametric Nonlinear Mixed Effects Modeling (NLME) was conducted using the PMETRICS R package while population pharmacokinetic model parameters were estimated using a FORTRAN compiler. Finally, model-based dosing simulations were conducted in the MATLAB Simbiology. RESULTS: A total of 51 patients were included in the final PK analysis. A two-compartment gamma multiplicative error model adequately described the propofol concentration-time data. The precision of the goodness-of-fit plots resulted in an R2 of 0.927 and an R2 of 0.992 for the population prediction and individual predictions, respectively. Neither the UGT1A9 nor the CYP2B6 G516T gene variants resulted in statistically significant PK parameter differences while the CYP2B6 A785G gene variants resulted in statistically significant differences for the elimination rate. Model-based dosing-simulations comparing patients with the CYP2B6 AA & AG genotypes to both GG genotypes and patients from a multicenter trial suggest a 50% decrease in propofol infusion dose, to 25mg/kg/min, be made to result in approximately equivalent drug exposures. CONCLUSION: Based on the pharmacometric modeling and simulation, if no dosage adjustments are made for the elderly CYP2B6 AA and AG genotypes, a 250% higher propofol blood exposure will be evident within 1-hour from the start of the infusion. Thus, based on the pharmacokinetic model, genotyping elderly patients for the CYP2B6 AA and AG gene variants will decrease the total propofol blood exposure during anesthesia and sedation when an infusion dose adjustment is made to 25mg/kg/min.

Impact of sleep disordered breathing on carotid body size.

We tested the hypotheses that: (1) carotid body size can be measured by computed tomographic angiography (CTA) with high inter-observer agreement, and (2) patients with sleep apnea exhibit larger carotid bodies than those without sleep apnea. A chart review was conducted from patients who underwent neck CTA and polysomnography at the Mayo Clinic between January 2000 and February 2015. Widest axial measurements of the carotid bodies, performed independently by two radiologists, were possible in 81% of patients. Intra-class correlation coefficients ranged from 0.93 to 0.95 (Right carotid body: 0.93; Left: 0.94; Average: 0.95). Widest axial measurements of the carotid bodies were greater in patients with sleep apnea (n=32) compared to controls (n=46, P-value range 0.02-0.04). After adjusting for age, no differences in carotid body size were observed between the patient groups (P-value range 0.45-0.59). We conclude carotid body size can be detected by CTA with high inter-observer agreement; however, carotid body size is not increased in patients with sleep apnea.

Metoprolol Dose Equivalence in Adult Men and Women Based on Gender Differences: Pharmacokinetic Modeling and Simulations.

Recent meta-analyses and publications over the past 15 years have provided evidence showing there are considerable gender differences in the pharmacokinetics of metoprolol. Throughout this time, there have not been any research articles proposing a gender stratified dose-adjustment resulting in an equivalent total drug exposure. Metoprolol pharmacokinetic data was obtained from a previous publication. Data was modeled using nonlinear mixed effect modeling using the MONOLIX software package to quantify metoprolol concentration-time data. Gender-stratified dosing simulations were conducted to identify equivalent total drug exposure based on a 100 mg dose in adults. Based on the pharmacokinetic modeling and simulations, a 50 mg dose in adult women provides an approximately similar metoprolol drug exposure to a 100 mg dose in adult men.

Gender based Dosing of Metoprolol in the Elderly using Population Pharmacokinetic Modeling and Simulations.

INTRODUCTION: This article seeks to clarify if gender-based differences occur in the pharmacokinetics of metoprolol in the elderly patients. There are a series of physiologic changes that occur in the elderly ranging from decreased hepatic blood flow to increased adiposity causing higher plasma concentrations at therapeutic doses as compared to the healthy young population. METHODS: Population pharmacokinetic modeling were performed using MONOLIX and Monte-Carlo simulations were conducted using MATLAB. The data was based from a previously published dataset where elderly patients, having multiple comorbidities, were administered a 50mg dose of metoprolol. RESULTS: Metoprolol was modeled using a one-compartment model and resulted in the following population pharmacokinetic parameters: volume of distribution, V=38L (CV=155%), clearance rates, CL-Men=105L/hour and CL-Women=59.1L/hour (38%), time lag, Tlag=0.469 hour (CV=17%), and the absorption rate constant, Ka=0.235 hr-1 (CV=23%). CONCLUSION: Gender stratified doses resulting in an equivalent systemic metoprolol exposure in geriatric patients have been identified. Metoprolol doses resulting a similar AUC in a healthy young male administered 50mg tablet were 15mg for geriatric women and 25mg for geriatric men. Further, Metoprolol doses of 25mg for geriatric women and 50mg for geriatric men resulted in an equivalent AUC to a healthy young males dosed with a 100mg tablet. A 15mg Metoprolol tablet may need to be compounded to account for the gender differences in Metoprolol pharmacokinetics.

Identifying Treatment Response of Sertraline in a Teenager with Selective Mutism using Electrophysiological Neuroimaging.

BACKGROUND: Selective Mutism is described as the inability to verbally express oneself in anxiety provoking social situations and may result in awkward social interactions in school-aged children. In this case-report we present the baseline electrophysiological neuroimaging results and after treatment with Sertraline for 6-weeks. METHODS: A 20-channel EEG event-related potential recording was acquired during an internal voice task at baseline prior to the initiation of 50mg of Sertraline and then repeated 6-weeks after treatment with Sertraline. EEG signals were processed for movement, eye-blink, and muscle artifacts and ERP signal averaging was completed. ERPs were analyzed using Standard Low Resolution Brain Electromagnetic Tomography (sLORETA). RESULTS: At baseline, Sertraline increased the neuronal activation in the middle temporal gyrus and the anterior cingulate gyrus from baseline in the patient following 6-weeks of treatment. CONCLUSION: Our findings suggest that electrophysiological neuroimaging may provide a creative approach for personalizing medicine by providing insight to the pharmacodynamics of antidepressants.

The influences of nitric oxide, epinephrine, and dopamine on vascular tone: dose-response modeling and simulations.

INTRODUCTION: Sodium Nitroprusside has successfully been an excellent choice when considering a decrease in systemic vascular resistance in the critical care setting. However, reflex tachycardia and ventilation-perfusion mismatch are possible side effects of this agent. To maintaining cardiac output, cerebral perfusion pressure, and concurrently drop SVR, low-dose epinephrine or dopamine are viable options. The aim of this paper is to conduct dose-response simulations to identify the equivalent dopamine, epinephrine, and nitroprusside infusion doses to decrease the systemic vascular resistance by 20% and by 40% from baseline resting values. METHODS: Three studies were identified in the literature with reported epinephrine, dopamine, and sodium nitroprusside infusion doses with corresponding systemic vascular resistance responses. Infusion doses were normalized to mcg/kg/min and SVR values were normalized and scaled to the percent decrease (%SVR) in SVR from baseline resting values. The original published studies were mathematically modeled and the Hill equation parameters used for further dose-response simulations of a virtual population. One-hundred patients were simulated various doses resulting in corresponding %SVR responses for each of the three drugs. RESULTS: Equivalent infusion doses achieving in an approximate 20-25% decrease in SVR, from baseline, were identified for epinephrine, dopamine, and sodium nitroprusside. Moreover, equivalent infusion doses were identified for epinephrine and nitroprusside to decrease the SVR by 40% from baseline. CONCLUSION: Even though sodium nitroprusside is traditionally used in decreasing SVR, low doses of dopamine or epinephrine are viable alternatives to patients with contraindications to nitroprusside infusions or who will require prolonged infusions to avoid toxicity. The multiple comparisons procedure-modeling approach is an excellent methodology for dose-finding exercises and has enabled identification of equivalent pharmacodynamic responses for epinephrine, dopamine, and sodium nitroprusside through mathematic simulations.

A Model-Based Meta-Analysis Evaluating Gender Differences on Blood Flow Responses to Brachial Artery Infusions of Acetylcholine, Albuterol, ATP, Bradykinin, Estradiol, Glyceryl Trinitrate, L-NMMA, Nevibolol, Norepinephrine, Sodium Nitroprusside, Substance P, and Verapamil.

INTRODUCTION: Numerous studies have emerged over the course of several decades describing the properties of drugs eliciting vasodilatory or vasoconstrictor responses in the human vasculature. During drug development, decisions to move forward with testing with a new chemical entity are very costly. To fund or not to fund development, go or no-go, decisions are often limited by efficacy comparisons with the current products on the market. The primary aim of this paper is to use dose-response modeling and simulations to quantify differences in blood flow to Acetylcholine, Albuterol, ATP, Bradykinin, 17ß-Estradiol, Glyceryl Trinitrate, L-NMMA, Nevibolol, Norepinephrine, Sodium Nitroprusside, Substance P, and Verapamil. METHODS: Five studies were identified in the literature that included a total of 12 compounds. Infusion doses were normalized to nmol/min and forearm blood flow values were normalized and scaled to the percent increase or decrease in forearm blood flow from baseline resting values. The original published studies were mathematically modeled using the Emax model or Sigmoid Emax model equation parameters. Lastly, dose-response simulations of higher doses using a virtual population were produced to account for population variability. RESULTS: The gender difference between the Emax estimates, interpreted as the %Change from Baseline resting forearm blood flow, were found to be: Albuterol 253%, Acetylcholine 231%, Substance P 159%, Verapamil 145%, Bradykinin 42%, Sodium Nitroprusside 41%, and Glyceryl Trinitrate 26%. Contrastingly, Norepinephrine and L-NMMA Emax gender difference resulted in a 6% and 7% difference, respectively. CONCLUSION: These results provide insight into the differences in men and women seen in anti-hypertensive patient management. Further, the modeling estimates provide pharmacometricians evaluating new compounds with mathematical parameters for comparative efficacy studies through the various phases of drug development.

A Clinical Trial Simulation Evaluating Epinephrine Pharmacokinetics at various Dosing Frequencies during Cardiopulmonary Resuscitation.

OBJECTIVE: This article seeks to test the hypothesis that repeated 1mg intravenous epinephrine dosing intervals of 3-minutes and 5-minutes results in differences in the total drug exposure and the maximum epinephrine concentration using simulated cardiopulmonary resuscitation (CPR) dosing. METHODS: Published population pharmacokinetic parameters were identified in the literature and pharmacokinetic dosing simulations were conducted according to the 2015 American Heart Association guidelines for CPR in adults. The stochastic pharmacokinetic simulations were conducted in MATLAB and R for statistical programming. RESULTS: A total of 5000 simulations were conducted in MATLAB while 90,000 data points for the 3-minute dosing interval and 150,000 data points for the 5-minute epinephrine dosing interval resulted from pharmacokinetic simulations in R. The difference between the 3-minute and 5-minute dosing intervals for patients with a SAP score of 30, were found to be: Male ΔAUC=2416 and ΔCmax=71, Female ΔAUC=1422 and ΔCmax=41, and for a 70kg patient ΔAUC=2968 and ΔCmax=90. While in virtual healthy participants, the differences were calculated to be ΔAUC=2658 and ΔCmax=81 for 3-minute and 5-minute dosing frequencies. CONCLUSIONS: Epinephrine plasma levels during a simulated CPR scenario in a virtual patient population are dependent upon intravenous dosing intervals of either 3-minutes or 5-minutes. Based on the results of this clinical trial simulation, implications may exist that may require clinical studies investigating the influence of the 1mg epinephrine dosing frequency on the return of spontaneous circulation.

Electrophysiological Neuroimaging using sLORETA Comparing 22 Age Matched Male and Female Schizophrenia Patients.

INTRODUCTION: The purpose of this electrophysiological neuroimaging study was to provide a deeper mechanistic understanding of both olanzapine and risperidone pharmacodynamics relative to gender. In doing so, we age-matched 22 men and women and evaluated their resting-state EEG recordings and later used standard low resolution brain Electrotomography to visualize the differences in brain activity amongst the two patient groups. METHODS: In this investigation, electroencephalogram (EEG) data were analyzed from male and female schizophrenia patients treated with either olanzapine or risperidone, both atypical antipsychotics, during their in-patient stay at the Department of Psychiatry. Twenty-two males and females were age-matched and EEG recordings were analyzed from 19 Ag/AgCl electrodes. Thirty-seconds of resting EEG were spectrally transformed in standardized low resolution electromagnetic tomography (sLORETA). 3D statistical non-paramentric maps for the sLORETA Global Field Power within each band were finally computed. RESULTS: The results indicated that, relative to males patients, females schizophrenia patients had increased neuronal synchronization in delta frequency, slow-wave, EEG band located in the dorsolateral prefrontal cortex, within the middle frontal gyrus (t= -2.881, p < 0.03580). These findings suggest that females experience greater dopamine (D2) receptor and serotonin (5-HT2) receptor neuronal blockade relative to age-matched males. Further, our finding provided insight to the pharmacodynamics of second-generation antipsychotics olanzapine and risperidone. CONCLUSION: When compared to male patients, female patients, suffering from schizophrenia, have D2 and 5-HT2 receptors that are blocked more readily than age-matched male schizophrenia patients. Clinically, this may translate into a quicker time to treatment-response in females as compared to male patients.

The Neuroprotective Aspects of Sleep.

Sleep is an important component of human life, yet many people do not understand the relationship between the brain and the process of sleeping. Sleep has been proven to improve memory recall, regulate metabolism, and reduce mental fatigue. A minimum of 7 hours of daily sleep seems to be necessary for proper cognitive and behavioral function. The emotional and mental handicaps associated with chronic sleep loss as well as the highly hazardous situations which can be contributed to the lack of sleep is a serious concern that people need to be aware of. When one sleeps, the brain reorganizes and recharges itself, and removes toxic waste byproducts which have accumulated throughout the day. This evidence demonstrates that sleeping can clear the brain and help maintain its normal functioning. Multiple studies have been done to determine the effects of total sleep deprivation; more recently some have been conducted to show the effects of sleep restriction, which is a much more common occurrence, have the same effects as total sleep deprivation. Each phase of the sleep cycle restores and rejuvenates the brain for optimal function. When sleep is deprived, the active process of the glymphatic system does not have time to perform that function, so toxins can build up, and the effects will become apparent in cognitive abilities, behavior, and judgment. As a background for this paper we have reviewed literature and research of sleep phases, effects of sleep deprivation, and the glymphatic system of the brain and its restorative effect during the sleep cycle.