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A physiologically based pharmacokinetic model (PBPK) was built for citalopram using Simcyp-based absorption, distribution, metabolism, and excretion simulator. Various physicochemical properties of citalopram were obtained from the published literature. The in vitro-in vivo extrapolation method was used to predict clearance in humans from recombinant enzyme data. Tissue distribution was predicted using parameter estimation function to fit the developed model to the observed concentration-versus-time data using nonlinear mixed-effects modeling approach. The model was verified by comparing the PBPK-based predictions with the observed pharmacokinetic (PK) profiles of citalopram in 26 clinical studies across a dose range of 10 to 60 mg. The predicted PK parameters of citalopram after intravenous dosing were within the -10% to 22% of the corresponding PK parameters obtained from the studies with quantified data sets. Most of the predicted PK parameters of citalopram after single-dose oral administration were within the 70%-130% range of the corresponding PK parameters obtained from observed data from 8 studies. After multidose oral administration, percentage error of C max and AUC was between -21% and 25% and -31% and 21%, respectively. Most of the observed data were within the 5th and 95th percentile interval of the variability around the predicted plasma concentrations. With the established model, the PK profiles in geriatric populations, populations with cytochrome P450 (CYP) 2C19 and/or 2D6 extensive metabolizers or poor metabolizers were predicted, and the predictions were in good agreement with the observed data. The model developed is robust to represent the absorption and disposition of citalopram and can predict the impact of patient covariates, such as age and genetic polymorphism of CYP2C19 and CYP2D6, on exposure of citalopram., (© 2019, The American College of Clinical Pharmacology.)

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., (© 2019 The Authors. Clinical Pharmacology & Therapeutics published by Wiley Periodicals, Inc. on behalf of American Society for Clinical Pharmacology and Therapeutics.)

Purpose: Co-prescription of paroxetine/fluoxetine (a strong CYP2D6 inhibitor) in metoprolol (a CYP2D6 substrate) users is common, but data on the clinical consequences of this drug-drug interaction are limited and inconclusive. Therefore, we assessed the effect of paroxetine/fluoxetine initiation on the existing treatment with metoprolol on the discontinuation and dose adjustment of metoprolol among elderly., Methods: We performed a cohort study using the University of Groningen IADB.nl prescription database (www.IADB.nl). We selected all elderly (≥60 years) who had ever been prescribed metoprolol and had a first co-prescription of paroxetine/fluoxetine, citalopram (weak CYP2D6 inhibitor), or mirtazapine (negative control) from 1994 to 2015. The exposure group was metoprolol and paroxetine/fluoxetine co-prescription, and the other groups acted as controls. The outcomes were early discontinuation and dose adjustment of metoprolol. Logistic regression was applied to estimate adjusted odds ratios (OR) and 95% confidence intervals (CI)., Results: Combinations of metoprolol-paroxetine/fluoxetine, metoprolol-citalopram, and metoprolol-mirtazapine were started in 528, 673, and 625 patients, respectively. Compared with metoprolol-citalopram, metoprolol-paroxetine/fluoxetine was not significantly associated with the early discontinuation and dose adjustment of metoprolol (OR = 1.07, 95% CI:0.77-1.48; OR = 0.87, 95% CI:0.57-1.33, respectively). In comparison with metoprolol-mirtazapine, metoprolol-paroxetine/fluoxetine was associated with a significant 43% relative increase in early discontinuation of metoprolol (OR = 1.43, 95% CI:1.01-2.02) but no difference in the risk of dose adjustment. Stratified analysis by gender showed that women have a significantly high risk of metoprolol early discontinuation (OR = 1.62, 95% CI:1.03-2.53)., Conclusion: Paroxetine/fluoxetine initiation in metoprolol prescriptions, especially for female older patients, is associated with the risk of early discontinuation of metoprolol., (© 2018 The Authors. Pharmacoepidemiology & Drug Safety published by John Wiley & Sons Ltd.)

Selective serotonin reuptake inhibitors (SSRI) and serotonin-norepinephrine reuptake inhibitors (SNRI) might be an effective treatment for hot flushes (HFs) in breast cancer survivors (BCSs). This study aims to compare the efficacy and tolerability of duloxetine (SNRI) versus escitalopram (SSRI) in reducing frequency and severity of HFs in BCSs and to assess the effect on depression. Thirty-four symptomatic BCSs with emotional impairment received randomly duloxetine 60 mg daily or escitalopram 20 mg daily for 12 weeks. Patients were asked to record in a diary HF frequency and severity at baseline and after 4 and 12 weeks of treatment. Depression was evaluated through validated questionnaires (Beck Depression Inventory and Montgomery Asberg Depression Rating Scale) at baseline and after 4 and 12 weeks of treatment. Both drugs showed a significant reduction of HF frequency and severity after 12 weeks of treatment with no significant difference between the two groups. A significant improvement in depression symptoms was observed at the end of the study period within both the groups, without difference between the two drugs. In conclusion, escitalopram and duloxetine are both effective treatment for the relief of HFs in BCSs, with similar beneficial effect. A significant improvement of depression was obtained with no major side effects., (© 2016 John Wiley & Sons Ltd.)

Introduction: To investigate whether early improvement can predict 8-week treatment outcome in generalized anxiety disorder (GAD) patients., Methods: For 8 weeks, 226 GAD patients were randomly treated with escitalopram or venlafaxine. Early improvement was defined as a ≧20% reduction from baseline in Hamilton anxiety rating scale at week 1 or 2. The positive and negative predictive values were calculated., Results: The positive and negative predictive values of early improvement in escitalopram or venlafaxine group at week 1 were (85.19%, 67.53%) vs (84.62%, 65.33%) DISCUSSION: The early improvement achieved within the first week treatment can predict a good 8-week treatment outcome in GAD patients., (© 2016 John Wiley & Sons Australia, Ltd.)

Background and Purpose: It has recently been suggested that 5-HT 3 receptor blockade enhances the efficacy of selective 5-HT (serotonin) reuptake inhibitor (SSRI) antidepressants and may reverse stress-induced deficits in rodents., Experimental Approach: To further explore this hypothesis, we used mice lacking the 5-HT 3 receptor (Htr3a KO) and their wild-type (WT) controls to assess their response in behavioural paradigms relevant to anxiety and depression. Mice were studied under basal, antidepressant treatments and chronic social defeat stress (CSDS) conditions., Key Results: In basal conditions, Htr3a KO mice displayed anxiolytic- and antidepressant-like behaviours in the elevated plus maze, the social interaction and the forced swim tests (FST), but behaved as WT mice in response to acute citalopram in the FST. However, the effects of fluoxetine were blunted in Htr3a KO mice in these same tests. In an in vitro electrophysiological paradigm, a low-dose citalopram treatment triggered 5-HT 1A receptor desensitization only in the dorsal raphe nucleus of Htr3a KO, although a high dose desensitized 5-HT 1A autoreceptor function equally in Htr3a KO and WT mice, suggesting that citalopram may become effective at lower doses when 5-HT 3 receptors are inactivated. In addition, Htr3a deletion blocked CSDS-induced modification in the cortical expression of two genes involved in oxidative stress, CaMKIIa and SOD1., Conclusions and Implications: Taken together, these data show that Htr3a deletion promotes SSRI efficacy and prevents the occurrence of stress-induced deleterious effects, suggesting that the 5-HT 3 receptor may represent an interesting target for the treatment of stress-related disorders., (© 2017 The British Pharmacological Society.)

Background and Purpose: The link between type 2 diabetes mellitus (T2DM) and depression is bidirectional. However, the possibility that metabolic disorders may elicit anxiogenic-like/depressive-like symptoms or alter the efficacy of antidepressant drugs remains poorly documented. This study explored the influence of T2DM on emotionality and proposed a therapeutic strategy that might be used in depressed diabetic patients., Experimental Approach: Mice were fed a high-fat diet (HFD) and subjected to a full comprehensive metabolic and behavioural analysis to establish correlations between metabolic and psychiatric disorders. In vivo intra-hippocampal microdialysis was also applied to propose a mechanism underpinning the phenotype of mice fed the HFD. Finally, we tested whether chronic administration of the selective 5-HT reuptake inhibitor escitalopram or HFD withdrawal could reverse HFD-induced metabolic and behavioural anomalies., Key Results: The increased body weight, hyperglycaemia and impaired glucose tolerance in response to HFD were correlated with anxiogenic-like/depressive-like symptoms. Moreover, this phenotype was associated with decreased extracellular 5-HT levels in the hippocampus which may result from increased sensitivity of the dorsal raphe 5-HT1A autoreceptor. Interestingly, the beneficial effect of prolonged administration of escitalopram was abolished in HFD-fed mice. On the contrary, HFD withdrawal completely reversed metabolic impairments and positively changed symptoms of anxiety, although some behavioural anomalies persisted., Conclusions and Implications: Our data provide clear-cut evidence that both pathologies are finely correlated and associated with impaired 5-HT mediated neurotransmission in the hippocampus. Further experiments are warranted to define the most adequate strategy for the treatment of such co-morbidity., Linked Articles: This article is part of a themed section on Updating Neuropathology and Neuropharmacology of Monoaminergic Systems. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v173.13/issuetoc., (© 2015 The British Pharmacological Society.)

Background: Chronic neuropathic pain can lead to anxiety and depression. Drugs that block reuptake of serotonin, norepinephrine and/or dopamine are widely used to treat depression, and have emerged as useful drugs in the treatment of neuropathic pain. This study compared the acute antinociceptive effects of NS18283, a novel triple monoamine reuptake inhibitor (MRI) with indatraline, venlafaxine and escitalopram in a mouse model of neuropathic pain., Method: Neuropathic pain-like behaviours were induced in mice by repeated injections of oxaliplatin (OXA), and assessed using the von Frey hair test, the cold plate test and the thermal preference plate test. Anxio/depressive phenotype and antidepressant-like properties of compounds were assessed by the novelty suppressed feeding test and the tail suspension test, respectively., Results: In vivo microdialysis experiments showed that each MRI increased extracellular serotonin, norepinephrine and/or dopamine levels in the cingulate cortex, in agreement with their in vitro reuptake inhibitory properties. Indatraline (3 mg/kg) reversed the full repertoire of OXA-induced neuropathic hypersensitivity. NS18283 (10 mg/kg) reversed OXA-induced mechano-hypersensitivity and cold allodynia. Venlafaxine (16 mg/kg) and escitalopram (4 mg/kg) only reversed cold allodynia and mechano-hypersensitivity, respectively. All MRIs produced antidepressant-like activity in anxio/depressive phenotype of OXA mice., Conclusions: Acute administration of drugs that enhance the activity of serotonin, norepinephrine and dopamine neurotransmission within nociceptive pathways may provide a broader spectrum of antinociception than dual or selective reuptake inhibitors in animal models of neuropathic pain. Whether similar observations would occur after repeated administration of such compounds in an attempt to simulate dosing in humans, or be compromised by dopaminergic-mediated adverse effects warrants further investigation., (© 2014 European Pain Federation - EFIC®)

To make an informed benefit-risk evaluation of a drug, a range of doses needs to be evaluated and its dose-response and exposure-response relationships for safety and effectiveness assessed during drug development (International Conference on Harmonisation E4). Once a safe and effective population dose (or doses) has been determined for indicated use(s), the individual patient dose can then be adjusted based on patient-specific factors (e.g., age, race, genetics, organ functions, concomitant medications).

In the three-arm 'gold standard' non-inferiority design, an experimental treatment, an active reference, and a placebo are compared. This design is becoming increasingly popular, and it is, whenever feasible, recommended for use by regulatory guidelines. We provide a general method to calculate the required sample size for clinical trials performed in this design. As special cases, the situations of continuous, binary, and Poisson distributed outcomes are explored. Taking into account the correlation structure of the involved test statistics, the proposed approach leads to considerable savings in sample size as compared with application of ad hoc methods for all three scale levels. Furthermore, optimal sample size allocation ratios are determined that result in markedly smaller total sample sizes as compared with equal assignment. As optimal allocation makes the active treatment groups larger than the placebo group, implementation of the proposed approach is also desirable from an ethical viewpoint., (Copyright © 2012 John Wiley & Sons, Ltd.)

Background: This study aims to explore differences in personal narratives of the experience of illness and treatment in depressed oncologic patients who received either combined treatment for depression (psychotherapy plus antidepressants) or standard treatment (antidepressants alone)., Methods: We employed a qualitative research design based on grounded theory. Data were collected from eight videotaped focus groups and semi-structured interviews with a total of 28 participants. The research team reviewed interview transcripts and categorized the participants' responses using the ATLAS.ti (ATLAS.ti Scientific Software Development GmbH Hardenbergstr. 7 D-10623, Berlin) software package., Results: Compared with patients in the standard treatment group, patients in the combined treatment group were better able to relate their experiences of physical and emotional discomfort and find meaning in the experience of illness by viewing cancer as a transformative experience. In addition, patients in the combined treatment group tended to use more active coping strategies based on acceptance of their situation and emphasized that psychotherapy had been helpful., Conclusions: Qualitative analysis is an efficient method of examining the meaning of quantitative results in depth, particularly patients' perspectives on quality of life. Patients undergoing combined treatment consider psychotherapy to be a helpful tool and exhibit more personal growth than do patients undergoing standard treatment., (Copyright © 2011 John Wiley & Sons, Ltd.)

Background: Depressive disorders are common in young people and are associated with significant negative impacts. Newer generation antidepressants, particularly selective serotonin reuptake inhibitors (SSRIs), are often used, however evidence of their effectiveness in children and adolescents is not clear. Furthermore, there have been warnings against their use in this population due to concerns about increased risk of suicidal ideation and behaviour., Objectives: To determine the efficacy and adverse outcomes, including definitive suicidal behaviour and suicidal ideation, of newer generation antidepressants compared with placebo in the treatment of depressive disorders in children and adolescents., Search Methods: For this update of the review, we searched the Cochrane Depression, Anxiety and Neurosis Review Group's Specialised Register (CCDANCTR) to October 2011. The CCDANCTR includes relevant randomised controlled trials from the following bibliographic databases: CENTRAL (the Cochrane Central Register of Controlled Trials) (all years), EMBASE (1974 -), MEDLINE (1950 -) and PsycINFO (1967 -). We searched clinical trial registries and pharmaceutical company websites. We checked reference lists of included trials and other reviews, and sent letters to key researchers and the pharmaceutical companies of included trials from January to August 2011., Selection Criteria: Published and unpublished randomised controlled trials (RCTs), cross-over trials and cluster trials comparing a newer generation antidepressant with a placebo in children and adolescents aged 6 to 18 years old and diagnosed with a depressive disorder were eligible for inclusion. In this update, we amended the selection criteria to include newer generation antidepressants rather than SSRIs only., Data Collection and Analysis: Two or three review authors selected the trials, assessed their quality, and extracted trial and outcome data. We used a random-effects meta-analysis. We used risk ratio (RR) to summarise dichotomous outcomes and mean difference (MD) to summarise continuous measures., Main Results: Nineteen trials of a range of newer antidepressants compared with placebo, containing 3335 participants, were included. The trials excluded young people at high risk of suicide and many co-morbid conditions and the participants are likely to be less unwell than those seen in clinical practice. We judged none of these trials to be at low risk of bias, with limited information about many aspects of risk of bias, high drop out rates and issues regarding measurement instruments and the clinical usefulness of outcomes, which were often variously defined across trials. Overall, there was evidence that those treated with an antidepressant had lower depression severity scores and higher rates of response/remission than those on placebo. However, the size of these effects was small with a reduction in depression symptoms of 3.51 on a scale from 17 to 113 (14 trials; N = 2490; MD -3.51; 95% confidence interval (CI) -4.55 to -2.47). Remission rates increased from 380 per 1000 to 448 per 1000 for those treated with an antidepressant. There was evidence of an increased risk (58%) of suicide-related outcome for those on antidepressants compared with a placebo (17 trials; N = 3229; RR 1.58; 95% CI 1.02 to 2.45). This equates to an increased risk in a group with a median baseline risk from 25 in 1000 to 40 in 1000. Where rates of adverse events were reported, this was higher for those prescribed an antidepressant. There was no evidence that the magnitude of intervention effects (compared with placebo) were modified by individual drug class., Authors' Conclusions: Caution is required in interpreting the results given the methodological limitations of the included trials in terms of internal and external validity. Further, the size and clinical meaningfulness of statistically significant results are uncertain. However, given the risks of untreated depression in terms of completed suicide and impacts on functioning, if a decision to use medication is agreed, then fluoxetine might be the medication of first choice given guideline recommendations. Clinicians need to keep in mind that there is evidence of an increased risk of suicide-related outcomes in those treated with antidepressant medications.

Treatment with some types of antidepressants has been associated with sudden cardiac death. It is unknown whether the increased risk is due to a class effect or related to specific antidepressants within drug classes. All patients in Denmark with an out-of-hospital cardiac arrest (OHCA) were identified (2001-2007). Association between treatment with specific antidepressants and OHCA was examined by conditional logistic regression in case-time-control models. We identified 19,110 patients with an OHCA; 2,913 (15.2%) were receiving antidepressant treatment at the time of OHCA, with citalopram being the most frequently used type of antidepressant (50.8%). Tricyclic antidepressants (TCAs; odds ratio (OR) = 1.69, confidence interval (CI): 1.14-2.50) and selective serotonin reuptake inhibitors (SSRIs; OR = 1.21, CI: 1.00-1.47) were both associated with comparable increases in risk of OHCA, whereas no association was found for serotonin-norepinephrine reuptake inhibitors/noradrenergic and specific serotonergic antidepressants (SNRIs/NaSSAs; OR = 1.06, CI: 0.81-1.39). The increased risks were primarily driven by: citalopram (OR = 1.29, CI: 1.02-1.63) and nortriptyline (OR = 5.14, CI: 2.17-12.2). An association between cardiac arrest and antidepressant use could be documented in both the SSRI and TCA classes of drugs.

Background: The co-occurrence of substance use disorder (SUD) and major depressive disorder (MDD) is common and is often thought to impair response to antidepressant therapy. These patients are often excluded from clinical trials, resulting in a significant knowledge gap regarding optimal pharmacotherapy for the treatment of MDD with concurrent SUD., Methods: In the Combining Medications to Enhance Depression Outcomes study, 665 adult outpatients with chronic and/or recurrent MDD were prospectively treated with either escitalopram monotherapy (escitalopram and placebo) or an antidepressant combination (venalfaxine-XR and mirtazapine or escitalopram and bupropion-SR). Participants with MDD and concurrent SUD (13.1%) were compared to those without SUD (86.9%) on sociodemographic and clinical characteristics at baseline and treatment response at 12- and 28-week endpoints., Results: The participants with MDD and SUD were more likely to be male and have current suicidal thoughts/plans, and had a greater lifetime severity and number of suicide attempts, and a higher number of concurrent Axis I disorders, particularly concurrent anxiety disorders. There were no significant differences between the MDD with or without SUD groups in terms of dose, time in treatment, response or remission at week 12 and 28. Furthermore, no significant differences in response or remission rates were noted between groups on the basis of the presence or absence of SUD and treatment assignment., Conclusions: Although significant baseline sociodemographic and clinical differences exist, patients with MDD and concurrent SUD are as likely to respond and remit to a single or combination antidepressant treatment as those presenting without SUD., (© 2012 Wiley Periodicals, Inc.)

Arterial spin labeling (ASL) allows noninvasive quantification of cerebral blood flow (CBF), which can be used as a biomarker of drug effects in pharmacological magnetic resonance imaging (phMRI). In a double-blind, placebo-controlled crossover study, we investigated the effects of a single oral dose of citalopram (20 mg) on resting CBF in 12 healthy subjects, using ASL phMRI. Support-vector machine (SVM) analysis detected significant drug-induced reduction in CBF in brain regions including the amygdala, fusiform gyrus, insula, and orbitofrontal cortex. These regions have been shown to have abnormally elevated CBF in patients with major depression, as well as in subjects genetically prone to depression. Mixed-effects analysis on data extracted from selected regions of interest (ROIs) revealed significant drug effect only in serotonergic areas of the brain (z = -4.45, P < 0.005). These results demonstrate the utility of ASL phMRI as a biomarker of pharmacological activity of orally administered drugs in the brain.

Objectives: More than half of older adults with major depressive disorder require extended treatment because of incomplete response during acute treatment. This study characterizes the effect of anxiety on remission during extended treatment for partial responders., Methods: Following 6 weeks of escitalopram 10 mg/day+depression care management (DCM), 124 partial responders (Hamilton Rating Scale for Depression (HRSD) scores of 11-14) were randomly assigned to receive extended treatment with escitalopram 20 mg/day+DCM with or without interpersonal psychotherapy (IPT) for 16 weekly sessions. Remission was defined as three consecutive weekly scores

Tramadol is O-demethylated to the active metabolite (+)-O-desmethyltramadol ((+)-M1) via CYP2D6, an enzyme that is weakly inhibited by escitalopram. We investigated the possibility of a pharmacokinetic (PK) and pharmacodynamic (PD) effect of escitalopram on tramadol metabolism. Fifteen healthy subjects completed this randomized, double-blind, three-phase, crossover trial. Combinations of escitalopram 20 mg/day or placebo together with tramadol 150 mg or placebo were used. Blood samples for pharmacokinetics were drawn at 0-24 h after medication. The analgesic effect of (+)-M was assessed by the cold pressor test (CPT) (area under effect curve, 1-12 h after medication (AUEC(1-12))). The median area under plasma concentration-time curve extrapolated to infinity (AUC(0-infinity)) of (+)-M1 was 2.75 micromol/l.h after placebo pretreatment compared with 1.95 micromol/l.h after escitalopram (P = 0.0027). The mean AUEC(1-12) of CPT were 4,140 and 4,388 cm.s after placebo and escitalopram, respectively (P = 0.71). Although escitalopram is a weak inhibitor of CYP2D6, it does not impair the analgesic effect of tramadol.

The objective of this study was to compare population pharmacokinetic models of escitalopram developed from dosage times recorded by a medication event monitoring system (MEMS) versus the reported times from patients with diagnosed depression. Seventy-three patients were prescribed doses of 10, 15, or 20 mg escitalopram daily. Sparse blood samples were collected at weeks 4, 12, 24, and 36 with 185 blood samples obtained from the 73 patients. NONMEM was used to develop a population pharmacokinetic model based on dosing records obtained from MEMS prior to each blood sample time. A separate population pharmacokinetic analysis using NONMEM was performed for the same population using the patient-reported last dosing time and assuming a steady-state condition as the model input. Objective function values and goodness-of-fit plots were used as model selection criteria. The absolute mean difference in the last dosing time between MEMS and patient-reported times was 4.48 +/- 10.12 hours. A 1-compartment model with first-order absorption and elimination was sufficient for describing the data. Estimated oral clearance (CL/F) to escitalopram was statistically insensitive to reported dosing methods (MEMS vs patient reported: 25.5 [7.0%] vs 26.9 [6.6%] L/h). However, different dosing report methods resulted in significantly different estimates on the volume of distribution (V/F; MEMS vs patient reported: 1000 [17.3%] vs 767 [17.5%] L) and the absorption rate constant K(a) (MEMS vs patient reported: 0.74 [45.7%] vs 0.51 [35.4%] h(-1)) for escitalopram. Furthermore, the parameters estimated from the MEMS method were similar to literature reported values for V/F ( approximately 1100 L) and K(a) ( approximately 0.8-0.9 h(-1)) arising from traditional pharmacokinetic approaches.

Recently, a novel allelic variant of cytochrome P450 2C19 encoding ultrarapid enzyme activity was described (denoted CYP2C19*17). The objective of this study was to evaluate the impact of CYP2C19*17 on serum concentration of escitalopram in psychiatric patients. One hundred and sixty-six patients treated with escitalopram were divided into the following subgroups according to CYP2C19 genotype: CYP2C19*17/*17 (n=7), CYP2C19*1/*17 (n=43), CYP2C19*1/*1 (n=60), CYP2C19*17/def (n=16), CYP2C19*1/def (n=34), and CYP2C19def/def (n=6) (def=defective allele, i.e., CYP2C19*2 or *3). Dose-adjusted serum concentrations of escitalopram were compared using the CYP2C19*1/*1 subgroup as reference. Geometric mean of the escitalopram serum concentration was 42% lower in patients homozygous for CYP2C19*17 (P<0.01) and 5.7-fold higher in subjects homozygous for defective CYP2C19 alleles (P<0.001). Of the heterozygous subgroups, only CYP2C19*1/def was significantly different from CYP2C19*1/*1 (P<0.001). In conclusion, a homozygous CYP2C19*17 genotype is associated with lower serum concentration of escitalopram, which might imply increased risk of therapeutic failure.

Background: Depressive disorders are common in young people and are associated with significant negative impacts. Selective serotonin reuptake inhibitors (SSRIs) are often used, however, evidence of their effectiveness in children and adolescents is not clear. Furthermore, there have been warnings against their use in this population due to concerns about increased risk of suicidal ideation and behaviour., Objectives: To determine the efficacy and adverse outcomes, including definitive suicidal behaviour and suicidal ideation, of SSRIs compared to placebo in the treatment of depressive disorders in children and adolescents., Search Strategy: We searched the CCDAN Trials Register, MEDLINE, PSYCHINFO and CENTRAL. Reference lists were checked, letters were sent to key researchers and internet databases searched., Selection Criteria: We included published and unpublished randomised controlled trials., Data Collection and Analysis: Two or three review authors selected the trials, assessed the quality and extracted trial and outcome data. We used a fixed-effect meta-analysis. The relative risk was used to summarise dichotomous outcomes and the mean difference to summarise continuous measures., Main Results: Twelve trials were eligible for inclusion, with ten providing usable data. At 8-12 weeks, there was evidence that children and adolescents 'responded' to treatment with SSRIs (RR 1.28, 95% CI 1.17 to 1.41). There was also evidence of an increased risk of suicidal ideation and behaviour for those prescribed SSRIs (RR 1.80, 95% CI 1.19 to 2.72). Fluoxetine was the only SSRI where there was consistent evidence from three trials that it was effective in reducing depression symptoms in both children and adolescents (CDRS-R treatment effect -5.63, 95% CI -7.38 to -3.88), and 'response' to treatment (RR 1.86, 95% CI 1.49 to 2.32). Where rates of adverse events were reported, this was higher for those prescribed SSRIs., Authors' Conclusions: Caution is required to interpret the results. First, there were methodological issues, including high attrition, issues regarding measurement instruments and clinical usefulness of outcomes, often variously defined across trials. Second, patients seen in clinical practice are likely to be more unwell, and at greater risk of suicide, compared to those in the trials, and it is unclear how this group would respond to SSRIs. This needs to be considered, along with the evidence of an increased risk of suicide related outcomes in those treated with SSRIs. It is unclear what the effect of SSRIs is on suicide completion. While untreated depression is associated with the risk of completed suicide and impacts on functioning, it is unclear whether SSRIs would modify this risk in a clinically meaningful way.

The pharmacokinetics of escitalopram (S-citalopram) and its principal metabolite, S-demethylcitalopram (S-DCT), were investigated after intravenous and oral administration to healthy subjects. After intravenous infusion of escitalopram, the mean systemic clearance and volume of distribution were 31 L/h and 1,100 L, respectively. After oral administration of single or multiple doses, the absorption was relatively fast, with the maximum observed plasma or serum concentration (C(max)) attained after 3 to 4 hours. The mean half-lives were 27 and 33 hours, respectively; steady state was attained within 10 days. The area under the plasma or serum concentration time curve from time zero to 24 hours and C(max) was both linear and proportional to the dose. The apparent volume of distribution was around 20 L/kg. Comparison of the systemic and oral clearance implied a high absolute bioavailability. There was no evidence of interconversion from S-citalopram to R-citalopram either in plasma or in urine. Concurrent intake of food had no effect on the pharmacokinetics of escitalopram or its metabolite. All treatments were well tolerated.

Objectives: Whether the effect of tricyclic antidepressants on Pain Disorder arises from their noradrenergic or serotonergic actions or both remains unclear. We compared the selective serotonin reuptake inhibitor (SSRI) citalopram and the noradrenergic reuptake inhibitor (NARI) reboxetine in outpatients with Pain Disorder. We also distinguished the drugs' analgesic and antidepressant effects., Methods: In this 8-week, randomized double-blind study, 35 patients with a DSM-IV-TR diagnosis of Pain Disorder were randomly assigned to receive either citalopram 40 mg/day (N=17 patients) or reboxetine 8 mg/day (N=18). The Present Pain Intensity (PPI) scale and the Total Pain Rating Index (tPRI) of the McGill Pain Questionnaire were used to measure the effect on pain symptoms. Changes in the Zung Self-Rating Depression Scale (Zung-D) scores were evaluated to monitor a possible antidepressant effect. For all patients who had at least one assessment, an intent-to-treat analysis was performed., Results: No significant differences were found in the demographic variables or clinical characteristics of the two treatment groups. In the citalopram group, PPI and tPRI scores measured at baseline decreased after treatment (tPRI: 41.9 vs. 30.0, p=.004; PPI: 3.5 vs. 2.8, p=.045) whereas in the reboxetine group differences were not statistically significant (tPRI: 35.2 vs. 31.5; PPI: 3.7 vs. 3.1). The Zung-D showed no significant changes between baseline and endpoint assessment in either group., Conclusions: Our study suggests that the SSRI citalopram may have a moderate analgesic effect in patients with Pain Disorder, and that this analgesic activity appears to be not correlated to changes in depressive scores. If confirmed in a larger sample, this evidence suggests that patients who are intolerant or resistant to tricyclic antidepressants, may be treated with SSRIs.

Results from randomized, placebo-controlled clinical trials have demonstrated that escitalopram is effective and well tolerated in the treatment of depression and anxiety disorders. Such trials typically employ stringent inclusion criteria that may limit the generalizability of findings to the broader population of patients treated in psychiatric and primary care practices. The objective of the current trial was to assess the effect of escitalopram treatment on depressed outpatients in naturalistic settings. This 8-week open-label trial enrolled 5,453 outpatients aged > or = 18 years with nonpsychotic major depressive disorder from primary care (n = 2,591), psychiatric (n = 2,289), and other specialty (n = 573) practices. Escitalopram was initiated at 10 mg/day, and dose could be increased to a maximum of 20 mg/day. Efficacy measures included the Clinical Global Impressions of Improvement (CGI-I) scale, Patient Global Evaluation (PGE) scale, Hospital Anxiety and Depression Scale, Sheehan Disability Scale, and 12-Item Short Form Health Survey. Overall, 76% of patients completed 8 weeks of treatment. The mean dose of escitalopram was 11.6 mg/day. At endpoint, response rates (defined as a score < or = 2 on the CGI-I or PGE) were 68% on the clinician-assessed CGI-I and 66% on the PGE. Improvement was not related to age or response to prior antidepressant treatment. Overall, 9% of patients discontinued due to adverse events. Escitalopram treatment was well tolerated and associated with robust response rates in a broadly representative population of depressed outpatients., (Copyright 2005 Wiley-Liss, Inc)

1 Microdialysis was used to study the acute and chronic effects of escitalopram (S-citalopram; ESCIT) and chronic citalopram (CIT), together with the 5-HT1A receptor antagonist WAY100,635 (N-[2-[methoxyphenyl)-1-piperazinyl]ethyl]-N-(2-pyridinyl) cyclohexane carboxamide trihydrochloride) and the 5-HT1A receptor agonist 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT), on extracellular 5-hydroxytryptamine (5-HT) levels in the rat prefrontal cortex. 2 Extracellular 5-HT rose to 234 and 298% of basal values after subcutaneous (s.c.) acute doses of 0.15 and 0.63 mg kg(-1) ESCIT. No further increase was observed at 2.5 mg kg(-1) ESCIT (290%). 3 The effect of 13-day s.c. infusion of 10 mg kg(-1) day(-1) ESCIT on extracellular 5-HT (422% of baseline) was greater than after 2 days (257% of baseline), whereas exposure to ESCIT was similar. In contrast, the increase in extracellular 5-HT induced by the infusion of CIT for 2 (306%) and 13 days (302%) was similar. However, brain and plasma levels of S-citalopram in rats infused with CIT for 13 days were lower than after 2 days. 4 Acute treatment with 2.5 mg kg(-1) ESCIT or 5 mg kg(-1) CIT raised extracellular 5-HT by 243 and 276%, respectively, in rats given chronic vehicle but had no effect in rats given ESCIT (10 mg kg(-1) day(-1)) or CIT (20 mg kg(-1) day(-1)) for 2 or 13 days, suggesting that the infused doses had maximally increased extracellular 5-HT. WAY100,635 (0.1 mg kg(-1) s.c.) increased extracellular 5-HT levels by 168, 174 and 169% of prechallenge values in rats infused with vehicle or ESCIT for 2 or 13 days, respectively. WAY100,635 enhanced extracellular 5-HT levels to 226, 153 and 164% of prechallenge values in rats infused with vehicle or CIT for 2 and 13 days, respectively. 5 8-OH-DPAT (0.025 mg kg(-1)) reduced extracellular 5-HT by 54% in control rats, but had no effect in those given ESCIT and CIT for 13 days. 6 This series of experiments led to the conclusion that chronic treatment with ESCIT desensitizes the 5-HT1A receptors, regulating the release of 5-HT in the prefrontal cortex and enhances the effect of the drug on extracellular 5-HT. They also indicate that chronic treatment with ESCIT and CIT did not prevent WAY100,635 from raising extracellular 5-HT.

Escitalopram has demonstrated efficacy for the acute treatment of social anxiety disorder (SAD) in two placebo-controlled trials and for long-term treatment in a relapse-prevention study. Social anxiety disorder is a heterogeneous disorder. This study questions whether this new selective serotonin reuptake inhibitor is effective across different subgroups of patients. Data from two randomised, placebo-controlled, 12-week escitalopram SAD trials were pooled. General linear models were used to determine the efficacy of escitalopram in different patient subgroups. Furthermore, a factor analysis of the primary efficacy scale, the Liebowitz Social Anxiety Scale (LSAS), was undertaken, and a determination made of whether treatment effects were similar for the different symptom dimensions. Escitalopram was effective in both younger and older patients, in male and female patients, and in patients with more and less severe social anxiety symptoms. The LSAS factor analysis showed six factors, which were differentially associated with different areas of disability. Escitalopram was significantly superior to placebo for all six symptom dimensions. The treatment effects of escitalopram were independent of gender, symptom severity and chronicity, and comorbid depressive symptoms. A six-factor model of social anxiety symptoms is supported by the distinctive association between these symptom dimensions and different areas of disability, but did not predict differential response to escitalopram., ((c) 2005 Wiley-Liss, Inc.)

Selective serotonin reuptake inhibitors are the pharmacological treatment of choice for the treatment of social anxiety disorder (SAD). The efficacy and tolerability of fixed doses of escitalopram were compared to those of placebo in the long-term treatment of generalised SAD, using paroxetine as an active reference. Patients with a DSM-IV diagnosis of SAD between 18-65 years of age were randomised to 24 weeks of double-blind treatment with placebo (n = 166), 5 mg escitalopram (n = 167), 10 mg escitalopram (n = 167), 20 mg escitalopram (n = 170), or 20 mg paroxetine (n = 169). Based on the primary efficacy parameter, Liebowitz Social Anxiety Scale (LSAS) total score at Week 12 (LOCF), a significantly superior therapeutic effect compared to placebo was seen for 5 and 20 mg escitalopram and for all doses for the OC analyses. Further improvement in LSAS scores was seen at Week 24 (OC and LOCF), with significant superiority over placebo for all doses of escitalopram, and 20 mg escitalopram was significantly superior to 20 mg paroxetine. Response to treatment (assessed by a Clinical Global Impression-Improvement score < or = 2) was significantly higher for all active treatments than for placebo at Week 12. Clinical relevance was supported by a significant decrease in all the Sheehan disability scores, and the good tolerability of escitalopram treatment. It is concluded that doses of 5-20 mg escitalopram are effective and well tolerated in the short- and long-term treatment of generalised SAD.

Escitalopram has been shown in clinical trials to improve anxiety symptoms associated with depression, panic disorder, and social anxiety disorder. This study was designed to evaluate the efficacy and tolerability of escitalopram in the treatment of generalized anxiety disorder (GAD). Outpatients (18 years or older) who met DSM-IV criteria for GAD, with baseline Hamilton Rating Scale for Anxiety (HAMA) scores > or = 18, were randomly assigned to double blind treatment with escitalopram (10 mg/day for the first 4 weeks and then flexibly dosed from 10-20 mg/day) or placebo for 8 weeks, following a 1-week, single-blind, placebo lead-in period. The primary efficacy variable was the mean change from baseline in total HAMA score at Week 8. The escitalopram group (N = 158) showed a statistically significant, and clinically relevant, greater improvement at endpoint compared with placebo (N = 157) in all prospectively defined efficacy parameters. Significant improvement in HAMA total score and HAMA psychic anxiety subscale score for the escitalopram-treated group vs. the placebo-treated group was observed beginning at Week 1 and at each study visit thereafter. Mean changes from baseline to Week 8 on the HAMA total score using a last-observation-carried-forward (LOCF) approach were -11.3 for escitalopram and -7.4 for placebo (P<.001). Response rates at Week 8 were 68% for escitalopram and 41% for placebo (P<.01) for completers, and 58% for escitalopram and 38% for placebo LOCF values (P<.01). Treatment with escitalopram was well tolerated, with low rates of reported adverse events and an incidence of discontinuation due to adverse events not statistically different from placebo (8.9% vs. 5.1%; P=.27). Escitalopram 10-20 mg/day is effective, safe, and well tolerated in the treatment of patients with GAD.

Experimental evidence suggests that panic disorder is characterized by abnormalities in the balance system function and that these abnormalities might be related to the severity of agoraphobic avoidance. Since the balance system can be modulated by the serotonergic system, we investigated the effect of a 6-week treatment with citalopram on the balance system function in patients with panic disorder. Fifteen patients with panic disorder with/without agoraphobia underwent static posturography on days 0 and 42. Static posturography and clinical assessments were carried out by different investigators who were blind to each other. Static posturography showed high percentages of abnormal scores. Patients with no or low agoraphobic avoidance showed less abnormal posturographic measures than those with moderate to severe agoraphobia. After 6 weeks of treatment with citalopram there was a significant decrease of four out of six posturography measures in eyes-closed and neck extension conditions, whereas no significant effect was found in the eyes-open condition. This is the first report that suggests that the modulation of the serotonergic system can improve the balance system function in patients with panic disorder, particularly when visual information is lacking. In addition, our findings confirm the observation that many patients with panic disorder have abnormalities in their balance system function, supporting the idea that these abnormalities are mainly related to agoraphobic avoidance., (Copyright 2003 Wiley-Liss, Inc.)

Background: Although citalopram has gained wide acceptance in the treatment of depression and anxiety disorders, its use during pregnancy and lactation has been poorly characterized. The aim of this study was to examine the efficacy and safety of citalopram in relation to concentrations of citalopram and its metabolites during pregnancy and lactation., Methods: Eleven mothers taking citalopram and their infants were enrolled in the study, and a control group of 10 women who were not taking medication were prospectively matched for confounding obstetric characteristics at the time of delivery. Plasma and breast milk samples were collected from mother/infant pairs during pregnancy, at delivery, and for up to 2 months after delivery. Trough plasma and breast milk concentrations of citalopram, desmethylcitalopram, and didesmethylcitalopram were measured by HPLC. The pregnancy outcome was recorded, and the neurodevelopment of children was monitored for up to 1 year., Results: Although the citalopram dose of 20 mg to 40 mg once daily resulted in low maternal trough plasma concentrations (range, 46-214 nmol/L) and metabolites during pregnancy, only one subject required an increase of daily dose. The mean didesmethylcitalopram-desmethylcitalopram metabolic ratio was significantly higher during pregnancy (54%, P <.001) than at 2 months after delivery, indicating induction of cytochrome P450 (CYP) 2D6 during pregnancy. At delivery, the trough plasma citalopram, desmethylcitalopram, and didesmethylcitalopram concentrations in the infants were 64%, 66%, and 68% of the maternal concentrations, respectively. The citalopram and metabolite concentrations in the milk were 2- to 3-fold higher compared with maternal plasma concentrations, but the infant citalopram and metabolite plasma concentrations were very low or undetectable. The delivery outcome and the neurodevelopment of all infants up to the age of 1 year were normal., Conclusion: Even though the sample size was limited, results from this prospective clinical trial suggest uncomplicated pregnancy outcome in mothers using citalopram during pregnancy and minimal exposure of the infants to citalopram during lactation. However, maternal therapeutic drug monitoring of citalopram should be recommended to minimize fetal exposure.

We assessed the tolerability and antidepressant response to citalopram in a group of patients who could not tolerate a recent trial of paroxetine therapy. Sixty-one outpatients with major depressive disorder and a confirmed history of intolerance to paroxetine (mean final dose: 26.7 mg/day) were switched after at least a 1 week washout to citalopram therapy (20 mg/day). During the 6-week, open label treatment protocol, citalopram could be titrated up to a maximum dose of 40 mg/day. Response was evaluated using the Clinical Global Impressions CGI scale, the 24-item Hamilton Rating Scale for Depression, and several other measures of symptoms and quality of life. Fifty-three patients (87%) completed 6 weeks of citalopram therapy (mean intent-to-treat dose: 23.9 mg/day). The specific side effects that were reported to be intolerable during the earlier paroxetine trial typically recurred only less than 30% of the time during citalopram therapy; only 6 patients (10%) dropped out because of adverse events. The intent-to-treat CGI response rate was 56% at study endpoint; 62% of the completers responded. Significant improvement from pretreatment was observed on various symptom measures after two weeks of citalopram therapy. Citalopram therapy was well tolerated, and more than one half of the patients who began treatment improved significantly. Although further work is necessary to assess the relative merits of this within-class switching strategy (as compared to other options), these data provide further evidence that the various selective serotonin reuptake inhibitors do not have interchangeable tolerability profiles., (Copyright 2002 Wiley-Liss, Inc.)

We studied 15 patients with dysthymic disorder with open-label citalopram. The purpose of this study was to determine the dose range and safety of citalopram necessary for treatment of patients with dysthymic disorder and to attempt to increase doses in order to enhance remission of patients with dysthymic disorder when treated. Citalopram was well tolerated. The mean dose used in this 10-week study was 37.3 mg and the majority of patients responded to treatment. Various criteria for response and remission were employed. These findings are intended to give guidelines for a subsequent treatment study of dysthymic patients with citalopram using a double-blind placebo-controlled strategy., (Copyright 2002 Wiley-Liss, Inc.)

We obtained information on the efficacy and safety of citalopram in settings that resemble actual clinical practice. A total of 1,783 patients participated in this open, uncontrolled, naturalistic Phase IV evaluation of citalopram at 447 U.S. investigative sites. Participants were selected by guidelines in the citalopram package insert using minimal exclusion criteria. Citalopram dosing began at 20 mg/day and could be titrated to 60 mg/day. Outcomes included the Clinical Global Impressions-Improvement scale (CGI-I) and a Patient Global Evaluation. Separate analyses were performed on patients with a primary diagnosis of major depressive disorder (MDD) (76%) who reported intolerance or nonresponse to previous selective serotonin reuptake inhibitors (SSRIs). Patients included tended to have treatment-resistant or intolerant, chronic or recurrent, comorbid depression with a mean duration of illness of 10 years. At study completion, more than 68% of treatment completers were classified as responders (CGI-I score of 1 or 2). Endpoint analyses showed response rates of 54% in all patients, 56% in patients with MDD, 49% in SSRI nonresponsive patients, and 53% in patients with a history of SSRI intolerance. Nausea (9.8%) and headache (7.3%) were the most often reported adverse events. Patients with a history of SSRI intolerance had a discontinuation rate of 21.8%, whereas those without such a history had a discontinuation rate of 13.3%. Citalopram administered at an average dose of 23.6 mg/day was associated with favorable outcomes and was generally well tolerated., (Copyright 2002 Wiley-Liss, Inc.)

The thymoleptic drug citalopram (CIT) belongs to the selective serotonin reuptake inhibitors (SSRIs) and is today extensively used in psychiatry. Further clarification of the enantiomer-selective distribution of racemic CIT in both clinical and toxic doses is highly warranted. By a steady-state in vivo paradigm, rats underwent chronic systemic exposure for 10 days by using osmotic pumps and the total as well as the individual distributions of the S- and R-enantiomers of CIT, and its metabolites in serum and two different brain regions, were analysed. In serum, the S/R ratios in the groups treated with 10, 20, or 100 mg kg(-1) day(-1) were 0.94, 0.83, and 0.34, respectively. The ratios were almost the same in the brain regions. In the group treated with 100 mg kg(-1) day(-1), the serum and brain total CIT levels were found to be 20 times and 6 - 8 times higher than in the rats treated with 10 or 20 mg kg(-1) day(-1), respectively. In all groups, the CIT levels were higher in brain tissue as compared to serum. In a spontaneous open-field behavioural test, a correlation between clinical and toxic drug concentrations was observed. In conclusion, the R-enantiomer was present in an increased proportion compared with the S-enantiomer when higher steady-state CIT concentration was prevailing. This is of particular interest, since the S-enantiomer is responsible for the inhibition of serotonin reuptake in vitro. The present data may be of importance, as full understanding on where different racemic or enantiomeric drug effects of CIT and its main metabolites are unravelled.