Fluvoxamine. An updated review of its use in the management of adults with anxiety disorders

The role of the methoxy group in approved drugs

The methoxy substituent is prevalent in natural products and, consequently, is present in many natural product-derived drugs. It has also been installed in modern drug molecules with no remnant of natural product features because medicinal chemists have been taking advantage of the benefits that this small functional group can bestow on ligand-target binding, physicochemical properties, and ADME parameters. Herein, over 230 methoxy-containing small-molecule drugs, as well as several fluoromethoxy-containing drugs, are presented from the vantage point of the methoxy group. Biochemical mechanisms of action, medicinal chemistry SAR studies, and numerous X-ray cocrystal structures are analyzed to identify the precise role of the methoxy group for many of the drugs and drug classes. Although the methoxy substituent can be considered as the hybridization of a hydroxy and a methyl group, the combination of these functionalities often results in unique effects that can amount to more than the sum of the individual parts.

An autopsy case of BRONTM overdose with multiple drug ingestion

A man in his forties was found dead in his friend's home, with moderate putrefaction. Quantitative toxicological analysis showed that concentrations of caffeine, chlorpheniramine, dihydrocodeine, and methylephedrine were 183.3 µg/mL, 0.533 µg/mL, 2.469 µg/mL and 8.336 µg/mL, respectively. Ephedrine, amitriptyline, nortriptyline, etizolam, fluvoxamine and 7-aminoflunitrazepam were detected in an aortic blood sample. Caffeine, chlorpheniramine, dihydrocodeine and methylephedrine are the main components of BRON^TM, an over-the-counter antitussive sold in Japan. Those concentrations in blood were within fatal ranges. Caffeine is classified as a methylxanthine and is mainly metabolized by cytochrome P450 (CYP)1A2. Fluvoxamine is a potent CYP1A2 inhibitor. Blood fluvoxamine concentration was within the therapeutic range, but would have increased blood caffeine level by the inhibition of caffeine metabolism. The conclusion was that his death was caused by BRON^TM overdose. Inhibition of caffeine metabolism may increase blood caffeine concentrations. This suggests that more attention should be paid to potential interactions between multiple drugs.

Effects of CYP2C19 inhibitors on mavacamten pharmacokinetics in rats based on UPLC-MS/MS

CONTEXT

CYP2C19 is an important member of the human cytochrome P450 2C (CYP2C) family. Mavacamten is a novel treatment of patients with symptomatic obstructive hypertrophic cardiomyopathy (HCM) which was metabolized mainly by CYP2C19.

OBJECTIVE

In this study, we firstly reported and validated a quantitative analysis method of mavacamten in rat plasma based on ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS), which was applied to the drug-drug interaction (DDI) study between mavacamten and CYP2C19 inhibitors (fluvoxamine, fluoxetine and fluconazole) in rats.

MATERIALS AND METHODS

Vericiguat was used as the internal standard (IS), and the analyte and IS were measured with electrospray ion (ESI) source in positive ion mode on a XEVO TQ-S triple quadrupole tandem mass spectrometer in multiple reaction monitoring (MRM) mode.

RESULTS

In the scope of 1.0-100 ng/mL, this assay had excellent linearity. Both intra-day and inter-day accuracy of the analyte ranged from -2.4% to 9.1%, while the precision was ≤4.2%. Matrix effect, recovery, and stability were evaluated and validated to meet the requirements for the guidelines of bioanalytical assay. When compared with the control group, AUC_0→∞ of mavacamten in fluconazole, fluoxetine and fluvoxamine were increased by 125.5%, 110.7% and 43.6%, respectively, which demonstrated that CYP2C19 inhibitors could inhibit mavacamten metabolism.

CONCLUSIONS

The results showed that CYP2C19 inhibitors could significantly improve the bioavailability of mavacamten in rats, which indicated that we should pay more attention to the patient's condition to prevent the occurrence of side effects when used mavacamten in combination with CYP2C19 inhibitors.

Fluvoxamine alleviates bleomycin-induced lung fibrosis via regulating the cGAS-STING pathway

Idiopathic pulmonary fibrosis (IPF) is a fatal disease with high mortality and limited effective therapy. Herein, we reported that fluvoxamine, a selective serotonin reuptake inhibitor (SSRI), used in depression and anxiety treatment, also exhibited therapeutic activities in IPF. Fluvoxamine inhibited cyclic GMP-AMP synthase (cGAS) and stimulator of interferon genes (STING), restrained the activation of their downstream targets, including PERK/ eIF2α/ c-Myc/ miR-9-5p/ TBPL1 and TBK1/ YAP/ JNK1/2/ Bnip3/ CaMKII/ cofilin signaling, thus attenuated the activation and migration of fibroblasts upon TGF-β1 challenge. Fluvoxamine dose-dependently improved pulmonary function, decreased the expression of inflammatory factors, reduced excessive production of extracellular matrix, and thus alleviated bleomycin (BLM)-induced lung fibrosis in mice. Moreover, fluvoxamine at a dose of 10 mg/ kg showed similar efficacy as pirfenidone (PFD) at a dose of 30 mg/kg in a mice model of lung fibrosis. In summary, our results suggest that fluvoxamine is an effective anti-fibrotic agent for IPF.

Deep brain stimulation for refractory obsessive-compulsive disorder: A review and analysis of the FDA MAUDE database

Background:

Deep brain stimulation (DBS) is used as a treatment option for patients diagnosed with a form of obsessive-compulsive disorder (OCD) that is highly resistant to conventional treatment methods. In 2009, DBS was granted a humanitarian device exemption-approval by the Food and Drug Administration after promising preliminary data. Monitoring of long-term safety data through post market surveillance of adverse events has not yet been conducted for DBS in OCD patients. This study aims to address this critical knowledge gap.

Methods:

All patient- and device-related (PR; DR) reports from January 1, 2012, to December 31, 2021, were downloaded and compiled from the manufacturer and user facility device experience (MAUDE) database pertaining to DBS for OCD using the product class name “Deep Brain Stimulator For OCD.” Data in this study were examined using descriptive statistics to evaluate for frequency of reporting.

Results:

The most frequently reported PR adverse event categories included psychiatric (40%), neurological (19%), other (14%), decreased therapeutic response (10%), and infections (10%). The most frequent DR reports were high impedance (14%), energy output problem (7%), battery problem (7%), malposition of device (7%), and improper/incorrect procedure or method (7%).

Conclusion:

The PR and DR adverse events in our study align with the previous findings of adverse events. They also further solidify that DBS for refractory OCD may be a viable option for the right patient population. However, further studies are essential given the limitations of the MAUDE database.

Stealth oxime ether lipid vesicles promote delivery of functional DsiRNA in human lung cancer A549 tumor bearing mouse xenografts

We previously reported that hydroxylated oxime ether lipids (OELs) efficiently deliver functional Dicer substrate siRNAs (DsiRNAs) in cells. Here, we explored in vivo utility of these OELs, using OEL4 as a prototype and report that surface modification of the OEL4 formulations was essential for their in vivo applications. These surface-modified OEL4 formulations were developed by inclusion of various PEGylated lipids. The vesicle stability and gene knock-down were dependent on the PEG chain length. OEL4 containing DSPE-PEG350 and DSPE-PEG1000 (surprisingly not DSPE2000) promoted gene silencing in cells. In vivo studies demonstrated that OEL4 vesicles formulated using 3 mol% DSPE-PEG350 accumulate in human lung cancer (A549-luc2) xenografts in mice and exhibit a significant increase in tumor to liver ratios. These vesicles also showed a statistically significant reduction of luciferase signal in tumors compared to untreated mice. Taken together, the scalable OEL4:DSPE-PEG350 formulation serves as a novel candidate for delivery of RNAi therapeutics.

Sigma non-opioid receptor 1 is a potential therapeutic target for long QT syndrome

Some missense gain-of-function mutations in CACNA1C gene, encoding calcium channel Ca_V1.2, cause a life-threatening form of long QT syndrome named Timothy syndrome, with currently no clinically-effective therapeutics. Here we report that pharmacological targeting of sigma non-opioid intracellular receptor 1 (SIGMAR1) can restore electrophysiological function in iPSC-derived cardiomyocytes generated from patients with Timothy syndrome and two common forms of long QT syndrome, type 1 (LQTS1) and 2 (LQTS2), caused by missense trafficking mutations in potassium channels. Electrophysiological recordings demonstrate that an FDA-approved cough suppressant, dextromethorphan, can be used as an agonist of SIGMAR1, to shorten the prolonged action potential in Timothy syndrome cardiomyocytes and human cellular models of LQTS1 and LQTS2. When tested in vivo, dextromethorphan also normalized the prolonged QT intervals in Timothy syndrome model mice. Overall, our study demonstrates that SIGMAR1 is a potential therapeutic target for Timothy syndrome and possibly other inherited arrhythmias such as LQTS1 and LQTS2.

The Place of Fluvoxamine in the Treatment of Non-critically ill Patients with COVID-19: A Living Systematic Review and Meta-analysis.. [DOI: 10.1101/2021.12.19.21268044]

Background

Fluvoxamine is a selective serotonin reuptake inhibitor that is known to be used as antidepressant. Repurposing of Fluvoxamine for the treatment of COVID-19 is theorized to help in the prevention of the clinical deterioration of SARS CoV-2 patients. In our systematic review and meta-analysis, we aim to assess the safety and efficacy of the drug under study in terms of its effect on the mortality and the risk of hospitalization and mechanical ventilation in non-critically ill COVID-19 patients.

Methods

We performed a systematic search of seven electronic databases. The search results were screened based on the previously determined inclusion and exclusion criteria. We determined the data related to our objectives. The mortality rates, rates of hospitalization, risk of mechanical ventilation and serious side effects were extracted from the studies that successfully met our inclusion and exclusion criteria. Then, the extracted data from the included studies was included in the meta-analysis.

Results

Three studies, two randomized clinical trials and one observational cohort study, with 1762 patients, were the final outcome of our search and screening processes. Among all participants, 886 patients received Fluvoxamine while 876 were controls. Follow up periods ranged from 7 days to 28 days. There was no significant difference in the intention-to-treat mortality rates between the two groups (RR = 0.66; 95% CI: 0.36 - 1.21, p-value = 0.18; I2 = 0%). However, Fluvoxamine decreased the per-protocol mortality compared to both placebo alone or placebo/standard care (RR = 0.09; 95% CI: 0.01 - 0.64, p-value = 0.02; I2 = 0% and RR = 0.09; 95% CI: 0.01 - 0.72, respectively). As compared to placebo or standard care, the all-cause hospitalization was significantly reduced in the fluvoxamine group (RR = 0.71; 95% CI: 0.54 - 0.93, p-value = 0.01; I2 = 61%). This risk reduction was not significant when compared to placebo alone (RR = 0.76; 95% CI: 0.57 - 1.00; p-value = 0.051; I2 = 48%). Furthermore, the risk of mechanical ventilation was not improved in the fluvoxamine group as compared to placebo (RR = 0.71; 95% CI: 0.43 - 1.16, p-value = 0.17; I2 = 0%). The serious adverse effects were almost the same in the treatment group and the control (13% and 12% respectively).

Conclusion

Fluvoxamine does not significantly reduce the mortality rates or the risk of mechanical ventilation in SARS CoV-2 patients. Nonetheless, it was found to have a good impact on reducing all cause hospitalization among patients with COVID-19 disease. Therefore, further clinical studies are needed to determine the effectiveness of the drug and its mechanisms of action.

Iridium-Catalyzed Acid-Assisted Hydrogenation of Oximes to Hydroxylamines

We found that cyclometalated cyclopentadienyl iridium(III) complexes are uniquely efficient catalysts in homogeneous hydrogenation of oximes to hydroxylamine products. A stable iridium C,N-chelation is crucial, with alkoxy-substituted aryl ketimine ligands providing the best catalytic performance. Several Ir-complexes were mapped by X-ray crystal analysis in order to collect steric parameters that might guide a rational design of even more active catalysts. A broad range of oximes and oxime ethers were activated with stoichiometric amounts of methanesulfonic acid and reduced at room temperature, remarkably without cleavage of the fragile N-O bond. The exquisite functional group compatibility of our hydrogenation system was further demonstrated by additive tests. Experimental mechanistic investigations support an ionic hydrogenation platform, and suggest a role for the Brønsted acid beyond a proton source. Our studies provide deep understanding of this novel acidic hydrogenation and may facilitate its improvement and application to other challenging substrates.

Drug repurposing of selective serotonin reuptake inhibitors: Could these drugs help fight COVID-19 and save lives?

The current 2019 novel coronavirus disease (COVID-19), an emerging infectious disease, is undoubtedly the most challenging pandemic in the 21st century. A total of 92,977,768 confirmed cases of COVID-19 and 1,991,289 deaths were reported globally up to January 14, 2021. COVID-19 also affects people's mental health and quality of life. At present, there is no effective therapeutic strategy for the management of this disease. Therefore, in the absence of a specific vaccine or curative treatment, it is an urgent need to identify safe, effective and globally available drugs for reducing COVID-19 morbidity and fatalities. In this review, we focus on selective serotonin reuptake inhibitors (SSRIs: a class of antidepressant drugs with widespread availability and an optimal tolerability profile) that can potentially be repurposed for COVID-19 and are currently being tested in clinical trials. We also summarize the existing literature on what is known about the link between serotonin (5-HT) and the immune system. From the evidence reviewed here, we propose fluoxetine as an adjuvant therapeutic agent for COVID-19 based on its known immunomodulatory, anti-inflammatory and antiviral properties. Fluoxetine may potentially reduce pro-inflammatory chemokine/cytokines levels (such as CCL-2, IL-6, and TNF-α) in COVID-19 patients. Furthermore, fluoxetine may help to attenuate neurological complications of COVID-19.

[Failed back surgery syndrome: the role of central sensitization and treatment approaches]

OBJECTIVE

To study a role of central sensitization (CS) in patients with Failed Back Surgery Syndrome (FBSS) after decompression of the lumbar and/or sacral roots.

MATERIAL AND METHODS

The study included three groups of patients: 1) early FBSS (e-FBSS, n=23), pain after surgery decreased, but continued to significantly bother the patient, or recurred in the first 6 months after surgery; 2) middle FBSS (m-FBSS, n=42), pain after surgery completely stopped, but recurred within 6-12 months; 3) late FBSS (l-FBSS, n=31), if pain relapse occurred more than 12 months later. Neurological status assessment, study of muscle trigger zones (MTZ), postoperative scar trigger zones (TZS), pain assessment according to the Visual Analogue Scale (VAS), CS assessment according to the Russian version of the Central Sensitization Inventory (CSI) were performed. Treatment included the following stages: stage 1 (non-steroidal anti-inflammatory drug (NSAID) meloxicam 15 mg 7 days); stage 2 (aminophenylbutyric acid hydrochloride (APAH) 250 mg 3 times a day 14 days); stage 3 (fluvoxamine 50 mg daily 8 weeks); stage 4 (MTZ and TZS treatment, fitness program). In addition to the previously described 96 patients, 15 patients (4 men and 11 women, aged 36-47 years) with FBSS and widespread pain, corresponding to the criteria for fibromyalgia ACTTION-APS Pain Taxonomy, who took only milnacipran 25-50 mg daily for two months (WSP-FBSS group), were studied.

RESULTS

At baseline, CSI and VAS are as follows: CSI=72.2±6.5; VAS=58.5±8.8 in the e-FBSS group; CSI=49.2±9.0; VAS=39.5±5.3 in the m-FBSS group; CSI=18.1±5.9; VAS=18.1±5.4 in the l-FBSS group. All patients have active MTZ and TZS. The differences between MTZ and TZS subgroups were in the reproduction of pain - the appearance of pain characteristic of the patient during stimulation (pressure) of the MTZ or TZS. In the e-FBSS group, there is the low efficacy of NSAIDs, the moderate efficacy of APAH, the high efficacy of fluvoxamine. In the m-FBSS group, the moderate efficacy of NSAIDs and APAH and the high efficacy of fluvoxamine are observed. In the l-FBSS group, there is the high efficacy of NSAIDs. In the WSP-FBSS group, VAS and CSI are 58.8±9.2 mm and 75.1±8.04, respectively, before treatment, 15.51±5.1 mm (p=0.00032) and 25.6±8.2 (p=0.0002), respectively, after 2 months of treatment.

CONCLUSIONS

In patients with FBSS, MTZ and TZS should be treated taking into account CS. The study shows the efficacy of APAH, fluvoxamine and milnacipran in the presence of CS.

Important Pharmacogenetic Information for Drugs Prescribed During the SARS-CoV-2 Infection (COVID-19)

In December 2019, the severe acute respiratory syndrome virus-2 pandemic began, causing the coronavirus disease 2019. A vast variety of drugs is being used off-label as potential therapies. Many of the repurposed drugs have clinical pharmacogenetic guidelines available with therapeutic recommendations when prescribed as indicated on the drug label. The aim of this review is to provide a comprehensive summary of pharmacogenetic biomarkers available for these drugs, which may help to prescribe them more safely.

Molecularly Imprinted Polymer Nanoparticles for Selective Solid Phase Extraction of Fluvoxamine in Human Urine and Plasma

In this work, the molecularly imprinted polymer nanoparticles (MIP-NPs) for the selective determination of fluvoxamine have been described. The polymer nanoparticles were synthesized by the polymerization of methacrylic acid as a functional monomer, ethylene glycol dimethacrylate as a cross-linker, 2,2-azobisisobutyronitrile as an initiator and fluvoxamine as a template molecule. The MIP-NPs were characterized using techniques that included Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM). Imprinted fluvoxamine molecules were removed from the polymeric structure using acetonitrile in methanol (2:8; v/v) as the eluting solvent. The linear dynamic range for fluvoxamine was 10-1200 μg L-1. The developed method was successfully applied to the extraction of fluvoxamine in complex biological samples.

Alopecia Scoring: The Quantitative Assessment of Hair Loss in Captive Macaques

Many captive animals show forms of pelage loss that are absent in wild or free-living con-specifics, which result from grooming or plucking behaviours directed at themselves or at other individuals. For instance, dorsal hair loss in primates such as rhesus macaques ( Macaca mulatta) in research facilities, results from excessive hair-pulling or over-grooming by cage-mates. This behaviour appears to be associated with stress, and is controllable to some extent with environmental enrichment. Quantifying alopecia in primates (as in many species) is therefore potentially useful for welfare assessment. A simple system for scoring alopecia was developed and its reliability was tested. Study 1 showed high interobserver reliability between two independent scorers in assessing the state of monkeys’ coats from photographs. Study 2 showed that there were no significant differences between the scores derived from photographs and from direct observations. Thus, where hair loss due to hair pulling exists in captive primates, this scoring system provides an easy, rapid, and validated quantitative method, for use in assessing the success of attempts to reduce it via improved husbandry. In the future, such scoring systems might also prove useful for quantifying barbering in laboratory rodents.

Yokukansan, a traditional Japanese herbal medicine, enhances the anxiolytic effect of fluvoxamine and reduces cortical 5-HT2A receptor expression in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Yokukansan is a traditional Japanese herbal medicine that has been approved in Japan as a remedy for neurosis, insomnia, and irritability in children. It has also been reported to improve behavioral and psychological symptoms in patients with various forms of dementia.

AIM OF THE STUDY

To evaluate the usefulness of co-treatment with an antidepressant and an herbal medicine in the psychiatric field, the current study examined the effect of yokukansan on the anxiolytic-like effect of fluvoxamine in mice.

MATERIALS AND METHODS

The anxiolytic-like effect in mice was estimated by the contextual fear conditioning paradigm. Contextual fear conditioning consisted of two sessions, i.e., day 1 for the conditioning session and day 2 for the test session. The expression levels of 5-HT_1A and 5-HT_2A receptor in the mouse brain regions were quantified by western blot analysis.

RESULTS

A single administration of fluvoxamine (5-20 mg/kg, i.p.) before the test session dose-dependently and significantly suppressed freezing behavior in mice. In the combination study, a sub-effective dose of fluvoxamine (5 mg/kg, i.p.) significantly suppressed freezing behavior in mice that had been repeatedly pretreated with yokukansan (0.3 and 1 g/kg, p.o.) once a day for 6 days after the conditioning session. Western blot analysis revealed that the expression level of 5-HT_2A receptor was specifically decreased in the prefrontal cortex of mice that had been administered yokukansan and fluvoxamine. Furthermore, microinjection of the 5-HT_2A receptor antagonist ketanserin (5 nmol/mouse) into the prefrontal cortex significantly suppressed freezing behavior.

CONCLUSION

The present findings indicate that repeated treatment with yokukansan synergistically enhances the anxiolytic-like effect of fluvoxamine in the contextual fear conditioning paradigm in mice in conjunction with a decrease in 5-HT_2A receptor-mediated signaling in the prefrontal cortex. Therefore, combination therapy with fluvoxamine and yokukansan may be beneficial for the treatment of anxiety disorders.

Early Life Stress, Depression And Parkinson's Disease: A New Approach

This review aims to shed light on the relationship that involves exposure to early life stress, depression and Parkinson's disease (PD). A systematic literature search was conducted in Pubmed, MEDLINE, EBSCOHost and Google Scholar and relevant data were submitted to a meta-analysis . Early life stress may contribute to the development of depression and patients with depression are at risk of developing PD later in life. Depression is a common non-motor symptom preceding motor symptoms in PD. Stimulation of regions contiguous to the substantia nigra as well as dopamine (DA) agonists have been shown to be able to attenuate depression. Therefore, since PD causes depletion of dopaminergic neurons in the substantia nigra, depression, rather than being just a simple mood disorder, may be part of the pathophysiological process that leads to PD. It is plausible that the mesocortical and mesolimbic dopaminergic pathways that mediate mood, emotion, and/or cognitive function may also play a key role in depression associated with PD. Here, we propose that a medication designed to address a deficiency in serotonin is more likely to influence motor symptoms of PD associated with depression. This review highlights the effects of an antidepressant, Fluvoxamine maleate, in an animal model that combines depressive-like symptoms and Parkinsonism.

The Effects of Fluvoxamine on the Steady-State Plasma Concentrations of Escitalopram and Desmethylescitalopram in Depressed Japanese Patients

BACKGROUND

The aim of this study was to determine the impact of fluvoxamine, an inhibitor of Cytochrome P450 (CYP) 2C19 (CYP2C19), on the pharmacokinetics of escitalopram, a substrate of CYP2C19.

METHODS

Thirteen depressed patients initially received a 20-mg/d dose of escitalopram alone. Subsequently, a 50-mg/d dose of fluvoxamine was administered because of the insufficient efficacy of escitalopram. Plasma concentrations of escitalopram and desmethylescitalopram were quantified using high-performance liquid chromatography before and after fluvoxamine coadministration. The QT and corrected QT (QTc) intervals were measured before and after fluvoxamine coadministration.

RESULTS

Fluvoxamine significantly increased the plasma concentrations of escitalopram (72.3 ± 36.9 ng/mL versus 135.2 ± 79.7 ng/mL, P < 0.01) but not those of desmethylescitalopram (21.5 ± 7.0 ng/mL versus 24.9 ± 12.0 ng/mL, no significance [ns]). The ratios of desmethylescitalopram to escitalopram were significantly decreased during fluvoxamine coadministration (0.37 ± 0.21 versus 0.21 ± 0.10, P < 0.01). The CYP2C19 genotype did not fully explain the degree of the change. Fluvoxamine coadministration did not change the QT or QTc intervals.

CONCLUSIONS

The results of this study suggest that adjunctive treatment with fluvoxamine increases the concentration of escitalopram. The QTc interval did not change in this condition.

Oxime Ether Lipids as Transfection Agents: Assembly and Complexation with siRNA

RNAi-based therapeutic approaches to combat cancer and other diseases are currently an area of great interest. However, practical applications of this approach rely on optimal tools to carry and deliver siRNA to the desired site. Oxime ether lipids (OELs) are a class of molecules among other various carriers being examined for siRNA delivery. OELs, relatively new candidates, belong to a class of non-glycerol based lipids and have begun to claim their place as an siRNA delivery carrier in the field of RNAi therapy. Chemical synthesis steps of OELs are considered relatively simple with the ability to modify the functionalities as desired. OEL-siRNA complexes can be assembled in the presence of serum-containing buffers (or cell culture media) and recent data from our and other groups have demonstrated that OELs are viable carriers for siRNA delivery in the cell culture systems. In this chapter, we provide the details of experimental protocols routinely used in our laboratory to examine OEL-siRNA complexes including their assembly, stability, and transfection efficiencies.

Oxime ether lipids containing hydroxylated head groups are more superior siRNA delivery agents than their nonhydroxylated counterparts

AIM

To evaluate the structure-activity relationship of oxime ether lipids (OELs) containing modifications in the hydrophobic domains (chain length, degree of unsaturation) and hydrophilic head groups (polar domain hydroxyl groups) toward complex formation with siRNA molecules and siRNA delivery efficiency of resulting complexes to a human breast cancer cell line (MDA-MB-231).

MATERIALS & METHODS

Ability of lipoplex formation between oxime ether lipids with nucleic acids were examined using biophysical techniques. The potential of OELs to deliver nucleic acids and silence green fluorescent protein (GFP) gene was analyzed using MDA-MB-231 and MDA-MB-231/GFP cells, respectively.

RESULTS & CONCLUSION

Introduction of hydroxyl groups to the polar domain of the OELs and unsaturation into the hydrophobic domain favor higher transfection and gene silencing in a cell culture system.

Quantitative assessment of photostability and photostabilisation of Fluvoxamine and its design for actinometry

Wavelength-dependent forwardand reverseFluvo quantum yields have been reported.

Involvement of the sigma1 receptor in the antidepressant-like effects of fluvoxamine in the forced swimming test in comparison with the effects elicited by paroxetine

We studied the involvement of the sigma(1) receptor in the antidepressant-like effects of the selective serotonin reuptake inhibitor (SSRI) fluvoxamine in DBA/2 mice using the forced swimming test. The effects of the selective sigma(1) receptor antagonist N-[2-(3,4-dichlorophenyl)ethyl]-N-methyl-2-(dimethylamino) ethylamine (BD1047) at 1mg/kg significantly antagonized the anti-immobility elicited by fluvoxamine (10mg/kg). However, the anti-immobility effects elicited by another SSRI, paroxetine (5m/kg), were not altered by BD1047. The selective sigma(1) receptor agonist 2S-(2α,6α,11R(*))-1,2,3,4,5,6-hexahydro-6,11-dimethyl-3-(2-propenyl)-2,6-methano-3-benzazocin-8-ol ((+)SKF-10047) elicited dose-dependent anti-immobility effects in DBA/2 mice. BD1047 significantly blocked the anti-immobility effects induced by (+)SKF-10047 at 10mg/kg. These results suggested that the sigma(1) receptor was associated with fluvoxamine-induced antidepressant-like effects but not with paroxetine-induced antidepressant-like effects.

Anxiolytic and Antidepressant-Like Effects of the Aqueous Extract of Alafia multiflora Stem Barks in Rodents

The present study examined the anxiolytic and antidepressant effects of the aqueous extract of Alafia multiflora Stapf (AM) stem barks (150 and 300 mg/kg, 7 days administration) on rats and mice, using experimental paradigms of anxiety and depression. In the open field, the aqueous extract increased significantly the number of center square crossed and the time spent at the center of the field as well as the rearing time, while the grooming time was reduced significantly. In the elevated plus maze, the aqueous extract increased the time spent and the number of entries in the open arms. All these effects were also completely reversed by flumazenil, an antagonist of benzodiazepine receptors and pindolol a β-adrenoceptors blocker/5-HT 1A/1B receptor antagonist. The time spent in the light compartment, the latency time, and the number of the light-dark transitions increased significantly in the light/dark exploration test after the treatment with AM. The extract was able to reduce significantly the immobility time and increase swimming as well as climbing duration. Taken together, the present work evidenced anxiolytic effects of the aqueous extract of AM that might involve an action on benzodiazepine-type receptors and an antidepressant effect where noradrenergic mechanisms will probably play a role.

Acute treatment with fluvoxamine elevates rat brain serotonin synthesis in some terminal regions: an autoradiographic study

INTRODUCTION

A considerable body of evidence indicates the involvement of the neurotransmitter serotonin (5-HT) in the pathogenesis and treatment of depression.

METHODS

The acute effect of fluvoxamine, on 5-HT synthesis rates was investigated in rat brain regions, using α-(14)C-methyl-L-tryptophan as a tracer. Fluvoxamine (25 mg/kg) and saline (control) were injected intraperitoneally, one hour before the injection of the tracer (30 μCi).

RESULTS

There was no significant effect of fluvoxamine on plasma free tryptophan. After Benjamini-Hochberg False Discovery Rate correction, a significant decrease in the 5-HT synthesis rate in the fluvoxamine treated rats, was found in the raphe magnus (-32%), but not in the median (-14%) and dorsal (-3%) raphe nuclei. In the regions with serotonergic axon terminals, significant increases in synthesis rates were observed in the dorsal (+41%) and ventral (+43%) hippocampus, visual (+38%), auditory (+65%) and parietal (+37%) cortex, and the substantia nigra pars compacta (+56%). There were no significant changes in the 5-HT synthesis rates in the median (+11%) and lateral (+24%) part of the caudate-putamen, nucleus accumbens (+5%), VTA (+16%) or frontal cortex (+ 6%).

CONCLUSIONS

The data show that the acute administration of fluvoxamine affects 5-HT synthesis rates in a regionally specific pattern, with a general elevation of the synthesis in the terminal regions and a reduction in some cell body structures. The reasons for the regional specific effect of fluvoxamine on 5-HT synthesis are unclear, but may be mediated by the presynaptic serotonergic autoreceptors.

Hydrophobic oxime ethers: a versatile class of pDNA and siRNA transfection lipids

The manipulation of the cationic lipid structures to increase polynucleotide binding and delivery properties, while also minimizing associated cytotoxicity, has been a principal strategy for developing next-generation transfection agents. The polar (DNA binding) and hydrophobic domains of transfection lipids have been extensively studied; however, the linking domain comprising the substructure used to tether the polar and hydrophobic domains has attracted considerably less attention as an optimization variable. Here, we examine the use of an oxime ether as the linking domain. Hydrophobic oxime ethers were readily assembled via click chemistry by oximation of hydrophobic aldehydes using an aminooxy salt. A facile ligation reaction delivered the desired compounds with hydrophobic domain asymmetry. Using the MCF-7 breast cancer, H1792 lung cancer and PAR C10 salivary epithelial cell lines, our findings show that lipoplexes derived from oxime ether lipids transfect in the presence of serum at higher levels than commonly used liposome formulations, based on both luciferase and green fluorescent protein (GFP) assays. Given the biological compatibility of oxime ethers and their ease of formation, this functional group should find significant application as a linking domain in future designs of transfection vectors.

Clinical usefulness of limited sampling strategies for estimating AUC of proton pump inhibitors

Cytochrome P450 (CYP) 2C19 (CYP2C19) genotype is regarded as a useful tool to predict area under the blood concentration-time curve (AUC) of proton pump inhibitors (PPIs). In our results, however, CYP2C19 genotypes had no influence on AUC of all PPIs during fluvoxamine treatment. These findings suggest that CYP2C19 genotyping is not always a good indicator for estimating AUC of PPIs. Limited sampling strategies (LSS) were developed to estimate AUC simply and accurately. It is important to minimize the number of blood samples because of patient's acceptance. This article reviewed the usefulness of LSS for estimating AUC of three PPIs (omeprazole: OPZ, lansoprazole: LPZ and rabeprazole: RPZ). The best prediction formulas in each PPI were AUC(OPZ)=9.24 x C(6h)+2638.03, AUC(LPZ)=12.32 x C(6h)+3276.09 and AUC(RPZ)=1.39 x C(3h)+7.17 x C(6h)+344.14, respectively. In order to optimize the sampling strategy of LPZ, we tried to establish LSS for LPZ using a time point within 3 hours through the property of pharmacokinetics of its enantiomers. The best prediction formula using the fewest sampling points (one point) was AUC(racemic LPZ)=6.5 x C(3h) of (R)-LPZ+13.7 x C(3h) of (S)-LPZ-9917.3 x G1-14387.2×G2+7103.6 (G1: homozygous extensive metabolizer is 1 and the other genotypes are 0; G2: heterozygous extensive metabolizer is 1 and the other genotypes are 0). Those strategies, plasma concentration monitoring at one or two time-points, might be more suitable for AUC estimation than reference to CYP2C19 genotypes, particularly in the case of coadministration of CYP mediators.

Fluvoxamine pharmacokinetics in healthy elderly subjects and elderly patients with chronic heart failure

AIMS

To investigate the effects of age and chronic heart failure (CHF) on the oral disposition kinetics of fluvoxamine.

METHODS

A single fluvoxamine dose (50 mg) was administered orally to 10 healthy young adults, 10 healthy elderly subjects and 10 elderly patients with CHF. Fluvoxamine concentration in plasma was measured for up to 96 h.

RESULTS

With the exception of apparent distribution volume, ageing modified all main pharmacokinetic parameters of fluvoxamine. Thus, peak concentration was about doubled {31 +/- 19 vs. 15 +/- 9 ng ml(-1); difference [95% confidence interval (CI)] 16 (3, 29), P < 0.05}, and area under the concentration-time curve was almost three times higher [885 +/- 560 vs. 304 +/- 84 ng h ml(-1); difference (95% CI) 581 (205, 957), P < 0.05]; half-life was prolonged by 63% [21.1 +/- 6.2 vs. 12.9 +/- 6.4 h; difference (95% CI) 8.2 (2.3, 14.1), P < 0.01], and oral clearance was halved (1.12 +/- 0.77 vs. 2.25 +/- 0.66 l h(-1) kg(-1); difference (95% CI) -1.13 (-1.80, -0.46), P < 0.001]. A significant inverse correlation was consistently observed between age and oral clearance (r=-0.67; P < 0.001). The coexistence of CHF had no significant effect on any pharmacokinetic parameters in elderly subjects.

CONCLUSIONS

Ageing results in considerable impairment of fluvoxamine disposition, whereas CHF causes no significant modifications. Therefore, adjustment of initial dose and subsequent dose titrations may be required in elderly subjects, whereas no further dose reduction is necessary in elderly patients with CHF.

Coprescription of tamoxifen and medications that inhibit CYP2D6

Evidence has emerged that the clinical benefit of tamoxifen is related to the functional status of the hepatic metabolizing enzyme cytochrome P450 2D6 (CYP2D6). CYP2D6 is the key enzyme responsible for the generation of the potent tamoxifen metabolite, endoxifen. Multiple studies have examined the relationship of CYP2D6 status to breast cancer outcomes in tamoxifen-treated women; the majority of studies demonstrated that women with impaired CYP2D6 metabolism have lower endoxifen concentrations and a greater risk of breast cancer recurrence. As a result, practitioners must be aware that some of the most commonly prescribed medications coadministered with tamoxifen interfere with CYP2D6 function, thereby reducing endoxifen concentrations and potentially increasing the risk of breast cancer recurrence. After reviewing the published data regarding tamoxifen metabolism and the evidence relating CYP2D6 status to breast cancer outcomes in tamoxifen-treated patients, we are providing a guide for the use of medications that inhibit CYP2D6 in patients administered tamoxifen.

Antidepressant-like effects of neferine in the forced swimming test involve the serotonin1A (5-HT1A) receptor in mice

The effects of neferine, an alkaloid of Nelumbo nucifera Gaertner embryos, on immobility in the forced swimming test, which is used to evaluate antidepressants, were investigated in mice. The administration of neferine from 25 to 100 mg/kg i.p. elicited anti-immobility effects in mice. The molecular dose effects of neferine in the forced swimming test were almost equal to those of the typical antidepressants maprotiline and imipramine. The involvement of the 5-HT receptor subtypes was also studied using 5-HT receptor antagonists. Anti-immobility effects of neferine are antagonized by the serotonin1A (5-HT1A) receptor antagonist, N-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]-N-(2-pyridinyl)cyclohexanecarboxamide (WAY 100635). However, the 5-HT1B receptor antagonist, 3-[3-(dimethylamino)propyl]-4-hydroxy-N-[4-(4-pyridinyl)phenyl] benzamide dihydrochloride (GR 55562), the 5-HT2 receptor antagonist, 6-methyl-1-(methylethyl)-ergoline-8beta-carboxylic acid 2-hydroxy-1-methylpropyl ester (LY 53857), the 5-HT3 receptor antagonist, ondansetron and the 5-HT4 receptor antagonist, 4-amino-5-chloro-2-methoxy-benzoic acid 2-(diethylamino)ethyl ester (SDZ 205,557) did not affect the anti-immobility effects of neferine. The anti-immobility effect of the selective 5-HT1A receptor agonist, 8-hydroxy-2-(di-n-propylamino)tetaralin (8-OH-DPAT) was also antagonized by WAY 100635. Furthermore, co-administration of subactive doses of neferine (10 mg/kg) and 8-OH-DPAT (0.1 mg/kg) produced synergistic antidepressant-like effects. These results suggest that neferine shows antidepressant-like effects in mice similar to typical antidepressants and that these effects are mediated by the 5-HT1A receptor. Therefore, the central effects of neferine are likely to be linked to serotonergic neurotransmission.

Involvement of the 5-HT(1A) receptor in the anti-immobility effects of fluvoxamine in the forced swimming test and mouse strain differences in 5-HT(1A) receptor binding

We previously demonstrated the presence of strain differences in baseline immobility time and sensitivity to the selective serotonin reuptake inhibitor (SSRI) fluvoxamine in five strains of mice (ICR, ddY, C57BL, DBA/2 and BALB/c mice). Furthermore, variations in serotonin (5-HT) transporter binding in the brain were strongly related to strain differences in baseline immobility and sensitivity to fluvoxamine. In the present study, we examined the involvement of the 5-HT(1A) receptor in anti-immobility effects in DBA/2 mice, which show high sensitivity to fluvoxamine. The anti-immobility effects of fluvoxamine in DBA/2 mice were inhibited by the 5-HT(1A) receptor antagonist N-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]-N-(2-pyridinyl)cyclohexanecarboxamide (WAY 100635). However, the 5-HT(1B) receptor antagonist 3-[3-(dimethylamino)propyl]-4-hydroxy-N-[4-(4-pyridinyl)phenyl]benzamide (GR55562), the 5-HT(2) receptor antagonist 6-methyl-1-(methylethyl)-ergoline-8beta-carboxylic acid 2-hydroxy-1-methylpropyl ester (LY 53857), the 5-HT(3) receptor antagonist ondansetron and the 5-HT(4) receptor antagonist 4-amino-5-chloro-2-methoxy-benzoic acid 2-(diethylamino)ethyl ester (SDZ 205,557) did not influence the anti-immobility effects of fluvoxamine in DBA/2 mice. These results suggest that fluvoxamine-induced antidepressant-like effects in DBA/2 mice are mediated by the 5-HT(1A) receptor. We analyzed 5-HT(1A) receptor binding in the brains of five strains of mice. Strain differences in 5-HT(1A) receptor binding were observed. 5-HT(1A) receptor binding in brain was not correlated with baseline immobility time in the five strains of mice examined. These results suggest that, although the anti-immobility effects of fluvoxamine in DBA/2 mice are mediated by the 5-HT(1A) receptor, strain differences in 5-HT(1A) receptor binding are not related to variation in immobility time and responses to fluvoxamine.

Suppression of dynamin GTPase activity by sertraline leads to inhibition of dynamin-dependent endocytosis

Dynamin (Dyn) 1 plays a role in recycling of synaptic vesicles, and thus in nervous system function. We previously showed that sertraline, a selective serotonin reuptake inhibitor (SSRI), is a mixed-type inhibitor of Dyn 1 with respect to both GTP and L-alpha-phosphatidyl-L-serine (PS) in vitro, and we suggested that it may regulate the neurotransmitter transport by modulating synaptic vesicle endocytosis via inhibition of Dyn 1 GTPase. Here, we investigated the effect of sertraline on endocytosis of marker proteins in human neuroblastoma SH-Sy5Y cells and HeLa cells. Sertraline inhibited endocytosis in both cell lines. Western blotting showed that SH-Sy5Y expresses Dyn 1 and Dyn 2, while HeLa expresses only Dyn 2. GTPase assay showed that sertraline inhibited Dyn 2 as well as Dyn 1. Therefore, the effect of sertraline on endocytosis was mediated by Dyn 2, at least in HeLa cells, as well as by Dyn 1 in cell lines that express it. Moreover, the inhibition mechanism of transferrin (Tf) uptake by sertraline differed from that in cells expressing Dyn 1 K44A, a GTP binding-defective variant, and sertraline did not interfere with the interaction between Dyn 1 and PS-liposomes.

Reversal of trichotillomania with aripiprazole

Trichotillomania (TTM) is a common psychiatric illness with marked chronicity and comorbidity that significantly impacts on psychosocial functioning and physical features of the sufferer. Treatment studies, to date, using behavioral and pharmacological interventions alone or simultaneously, are equivocal with few showing a sustained cessation of hair-plucking. In this report of a single patient with treatment resistant TTM, the sole use of the atypical neuroleptic Aripiprazole resulted in a cessation of hair-plucking maintained, at the time of reporting, for a period of 24 months. This finding, a first with Aripiprazole, warrants further investigation of this drug in the treatment of TTM.

Different effects of fluvoxamine on rabeprazole pharmacokinetics in relation to CYP2C19 genotype status

AIMS

Rabeprazole is known to be a substrate of CYP2C19. Our objective was to evaluate the possible effect of an inhibitor of CYP2C19, fluvoxamine, and compare the inhibitory effect of fluvoxamine on the metabolism of rabeprazole between CYP2C19 genotypes.

METHODS

A two-way randomized double-blind, placebo-controlled crossover study was performed. Twenty-one volunteers, of whom seven were homozygous extensive metabolizers (EMs), eight were heterozygous EMs and six were poor metabolizers (PMs) for CYP2C19, received two 6-day courses of either fluvoxamine 50 mg or placebo daily in a randomized fashion with a single oral dose of rabeprazole 20 mg on day 6 in all cases. Plasma concentrations of rabeprazole and its metabolite rabeprazole thioether were monitored up to 24 h after dosing.

RESULTS

During placebo administration, the mean AUCs(0,infinity) of rabeprazole in homozygous EMs, heterozygous EMs and PMs were 882 (95% CI, 602, 1162) ng ml-1h , 1214 (975, 1453) ng ml-1 h and 2762 (2482, 3042) ng ml-1 h (P<0.001), respectively. Fluvoxamine treatment increased AUC(0,infinity) of rabeprazole and rabeprazole thioether by 2.8-fold (P<0.001) and 5.1-fold (P<0.01) in homozygous EMs, and by 1.7-fold (P<0.01) and 2.6-fold (P<0.01) in heterozygous EMs, and significantly prolonged the elimination half-life of rabeprazole and rabeprazole thioether in homozygous EMs and in heterozygous EMs, whereas no difference in any pharmacokinetic parameters was found in PMs. There was a significant difference in fluvoxamine-mediated percentage increase in AUC(0,infinity) of rabeprazole and rabeprazole thioether between CYP2C19 genotypes.

CONCLUSIONS

The present study indicates that there are significant drug interactions between rabeprazole and fluvoxamine in EMs of CYP2C19. It is predominantly involved in rabeprazole and rabeprazole thioether metabolism in EMs. Therefore, CYP2C19 is the key determinant of rabeprazole disposition in EMs.

Identification of the time-point which gives a plasma rabeprazole concentration that adequately reflects the area under the concentration-time curve

OBJECTIVE

The purpose of this study is to evaluate whether a simple formula using limited blood samples can predict the area under the plasma rabeprazole concentration-time curve (AUC) in co-administration with CYP inhibitors.

METHODS

A randomized double-blind placebo-controlled crossover study design in three phases was conducted at intervals of 2 weeks. Twenty-one healthy Japanese volunteers, including three CYP2C19 genotype groups, took a single oral 20-mg dose of rabeprazole after three 6-day pretreatments, i.e., clarithromycin 800 mg/day, fluvoxamine 50 mg/day, and placebo. Prediction formulas of the AUC were derived from pharmacokinetics data of 21 subjects in three phases using multiple linear regression analysis. Ten blood samples were collected over 24 h to calculate AUC. Plasma concentrations of rabeprazole was measured by an HPLC-assay (l.l.q.=1 ng/ml).

RESULTS

The AUC was based on all the data sets (n=63). The linear regression using two points (C3 and C6) could predict AUC(0-infinity) precisely, irrespective of CYP2C19 genotypes and CYP inhibitors (AUC(0-infinity)=1.39xC3+7.17xC6+344.14, r (2)=0.825, p<0.001).

CONCLUSION

The present study demonstrated that the AUC of rabeprazole can be estimated by the simple formula using two-point concentrations. This formula can be more accurate for the prediction of AUC estimation than that reflected by CYP2C19 genotypes without any determination, even if there are significant differences for the CYP2C19 genotypes. Therefore, this prediction formula might be useful to evaluate whether CYP2C19 genotypes really reflects the curative effect of rabeprazole.

Comparison of efficacy and tolerability of reboxetine and venlafaxine XR in major depression and major depression with anxiety features: an open label study

OBJECTIVE

The aim of this study was to compare the efficacy and tolerability of reboxetine in the treatment of major depressive disorder (MDD) and MDD with anxiety features to venlafaxine XR.

METHOD

Patients with MDD, aging 18 between 65 years, were randomly allocated to two groups receiving either open-label venlafaxine XR capsules (n = 50) or reboxetine tablets (n = 43). Subjects were administered Hamilton Depression Rating Scale (HAM-D) and Hamilton Anxiety Scale (HAM-A) at baseline and 2, 4, 7, 10 weeks after the baseline visit.

RESULTS

Response rates to antidepressant treatment were significantly higher in the venlafaxine XR group at 10th week. When patients having anxious depression were analysed separately; response rate for anxiety of reboxetine group was significantly higher at 7th week only. Mean number of side effects were significantly higher in reboxetine group. Only one subject in each group was dropped out due to side effect.

CONCLUSION

We may suggest that reboxetine is as effective and tolerable as venlafaxine XR in the treatment of MDD and MDD with anxiety features, and it may be considered a treatment option to venlafaxine XR.

Identification of a Single Time-point for Plasma Lansoprazole Measurement That Adequately Reflects Area Under the Concentration-Time Curve

The objective of this study was to identify a single time-point for plasma lansoprazole measurement that adequately reflects area under the plasma lansoprazole concentration-time curve (AUC) after administration of lansoprazole alone or together with coadministration with CYP mediators. A randomized double-blind placebo-controlled crossover study design in 3 phases was conducted at intervals of 2 weeks. Eighteen healthy Japanese volunteers, comprising 3 CYP2C19 genotype groups, took a single oral 60-mg dose of lansoprazole after three 6-day pretreatments, that is, clarithromycin 800 mg/d, fluvoxamine 50 mg/d, and placebo. Blood samplings (10 mL each) for determination of lansoprazole were taken up to 24 hours after the administration of lansoprazole. Correlation between plasma lansoprazole concentrations at various time points and AUC0-24 were analyzed. Although there were significant differences in the pharmacokinetic parameters of lansoprazole during clarithromycin and placebo among CYP2C19 genotypes, the differences were not found during fluvoxamine. The plasma concentrations 3, 4, 6, and 8 hours after administration (C3, C4, C6, and C8, respectively) were highly correlated with AUC0-24 in coadministration with placebo, clarithromycin, and fluvoxamine (r>0.8, P<0.001). In particular, C6 showed a correlation coefficient of 0.940, 0.992, and 0.953 in coadministration with placebo, clarithromycin, and fluvoxamine, respectively, and was the most appropriate for estimating AUC0-24. The present study demonstrates that AUC of lansoprazole can be estimated by using a single time-point at C6. This method of plasma concentration monitoring at one time-point might be more suitable for AUC estimation than reference to CYP2C19 genotypes, particularly in coadministration of CYP mediators.

The effects of cannabinoids on contextual conditioned fear in CB1 knockout and CD1 mice

We studied the effects of cannabinoids on contextual conditioned fear responses. CB1 knockout and wild-type (CD1) mice were exposed to a brief session of electric shocks, and their behavior was studied in the same context 24 h later. In wild-type mice, shock exposure increased freezing and resting, and decreased locomotion and exploration. The genetic disruption of the CB1 receptor abolished the conditioned fear response. The CB1 antagonist AM-251 reduced the peak of the conditioned fear response when applied 30 min before behavioral testing (i.e. 24 h after shocks) in CD1 (wild-type) mice. The cannabinoid agonist WIN-55,212-2 markedly increased the conditioned fear response in CD1 mice, the effect of which was potently antagonized by AM-251. Thus, cannabinoid receptor activation appears to strongly promote the expression of contextual conditioned fear. In earlier experiments, cannabinoids did not interfere with the expression of cue-induced conditioned fear but strongly promoted its extinction. Considering the primordial role of the amygdala in simple associative learning (e.g. in cue-induced fear) and the role of the hippocampus in learning more complex stimulus relationships (e.g. in contextual fear), the present and earlier findings are not necessarily contradictory, but suggest that cannabinoid signaling plays different roles in the two structures. Data are interpreted in terms of the potential involvement of cannabinoids in trauma-induced behavioral changes.