Efficacy of intravenous citalopram compared with oral citalopram for severe depression. Safety and efficacy data from a double-blind, double-dummy trial

Association between antidepressant use and delirium in older adults: an analysis of the World Health Organization's global pharmacovigilance database

BACKGROUND

Psychoactive drugs frequently cause delirium adverse events in older adults. However, few data on the relationship between antidepressants and delirium are available. Here, we investigated the association between antidepressant prescription and pharmacovigilance reports of delirium in older adults.

METHODS

Using the World Health Organization's VigiBase® global pharmacovigilance database from 1967 to 2022, we performed a disproportionality analysis in order to probe the putative associations between each antidepressant class (non-selective monoamine reuptake inhibitors (NSMRIs), selective serotonin reuptake inhibitors (SSRIs), serotonin-norepinephrine reuptake inhibitors (SNRIs), monoamine oxidase inhibitors (MAOIs), alpha-2-adrenergic receptor antagonists, and other antidepressants) and reports of delirium in people aged 65 or over. We calculated the reporting odds ratios (r-OR) and their 95% confidence interval ([95%CI]) with logistic regression models before and after adjustment for confounding factors. Secondary analyses were performed for each drug and within each class by age group (65-74, and 75 and over). We also studied the reports of concomitant delirium and hyponatremia.

RESULTS

Our main analysis included 87,524 cases of delirium. After adjustment for confounders, a significant association was found between delirium and all antidepressant classes other than SNRIs. Intraclass disparities were found for the association between the most frequently prescribed antidepressants and reports of delirium. An elevated risk of reports of concomitant delirium and hyponatremia was found for SSRIs (4.46 [4.01-4.96]), SNRIs (1.25 [1.07-1.46]), MAOIs (1.72 [1.41-2.09]), and the "other antidepressants" class (1.47 [1.30-1.65]).

CONCLUSIONS

There was a significant association between reports of delirium and antidepressant classes (other than SNRIs). However, this association varied from one drug to another within a given antidepressant class. Moreover, this association could not always be explained by antidepressant-induced hyponatremia.

Intranasal administration of sertraline ensures sustained brain delivery and antidepressant effect in a mouse model of depression

The pursuit of more potent and efficacious antidepressant therapies is of utmost significance. Herein, the intranasal (IN) route was investigated for sertraline brain delivery, encompassing a comparative pharmacokinetic study after a single-dose administration to mice by IN, intravenous (IV) (4.87 mg/kg) and oral (10 mg/kg) routes, and an efficacy/toxicity study to explore the therapeutic effect in mice subjected to the unpredictable chronic mild stress (UCMS) protocol. Neurotransmitters and melatonin were quantified in prefrontal cortex and plasma, respectively. A different drug biodistribution behavior was unveiled for a CNS-acting drug administered by means of the IN route. For the first time, IN administration of sertraline exhibited heightened systemic exposure (bioavailability = 166 %), and a sustained drug release into the brain, in opposition to IV and oral routes, avoiding drug fluctuation. The lower lung exposition (given by normalized area under the curve) observed after IN instillation envisions the reduction of sertraline pulmonary side effects and similarly other peripheral side effects. IN sertraline treatment displayed significant efficacy in ameliorating anhedonia after one week of administration while the 14-day IN treatment regimen translated into decreased immobility time and increased swimming time in the forced swimming test, suggesting an improvement of the depressive-like behavior displayed by the animal depressive-model. Remarkably, these effects were absent with oral sertraline, despite the higher used dose. Noteworthy neurotransmitter alterations were observed, with IN sertraline markedly reducing adrenaline in the prefrontal cortex, while serotonin and melatonin increased following both administration routes. With its sustained brain delivery and serotonin- and melatonin-enhancing potential, the innovative strategy of IN sertraline holds the potential not only to effectively address depressive symptoms but also to mitigate challenges inherent to classic treatments.

Intravenous vortioxetine to accelerate onset of effect in major depressive disorder: a 2-week, randomized, double-blind, placebo-controlled study

This 2-week randomized, double-blind, placebo-controlled fixed-dose study (NCT02919501) explored the potential of accelerating onset of antidepressant efficacy and plasma exposure with single-dose intravenous vortioxetine at oral vortioxetine treatment initiation. Outpatients (ages 18-65 years) with major depressive disorder and a current depressive episode (Montgomery Åsberg Depression Rating Scale total score ≥30) were randomized to an initial single dose of either intravenous vortioxetine 17 mg (n = 27) or intravenous placebo (n = 28), both treatments followed by 2 weeks of oral vortioxetine (10 mg/day). From baseline to day 7, both groups exhibited fast and substantial improvements by approximately 14 Montgomery Åsberg Depression Rating Scale points, with no statistically significant treatment difference for this primary endpoint. Improvements were substantial already within 24 hours, with numerical treatment differences of 1.3 and 1.6 points at days 1 and 3, respectively, in favour of intravenous vortioxetine + oral vortioxetine. Pharmacokinetic data confirmed that intravenous vortioxetine facilitated reaching steady-state plasma concentration within 24 hours. Intravenous vortioxetine + oral vortioxetine was safe and well-tolerated, with nausea as the most common adverse event. This study supported intravenous vortioxetine as a means of rapidly reaching therapeutic vortioxetine blood levels.

Is trazodone more effective than clomipramine in major depressed outpatients? A single-blind study with intravenous and oral administration

OBJECTIVE

Some antidepressants, such as trazodone or clomipramine, can be administered intravenously in patients with major depressive disorder (MDD), with potential benefits compared to the standard oral treatment, but available data about their efficacy are limited. The present study was aimed to compare the effectiveness of trazodone and clomipramine (intravenous [i.v.] followed by oral administration).

METHODS

Some 42 patients with a diagnosis of MDD according to the DSM-5 were selected and treated with i.v. trazodone or clomipramine according to clinical judgment. The Hamilton Depression Rating Scale, the Hamilton Anxiety Rating Scale, and the Montgomery-Åsberg Depression Rating Scale were administered at baseline, after 2 weeks, and after 6 weeks, as well as after 1 week of intravenous antidepressant administration. Raters were blinded to type of treatment.

RESULTS

No significant differences were found between treatment groups in terms of effectiveness at endpoint. Borderline statistical significance was found in terms of number of responders in favor of trazodone. In addition, patients treated with trazodone reported fewer total side effects than those treated with clomipramine.

CONCLUSION

Both i.v. trazodone and clomipramine are rapid and effective options for improving depressive symptoms, although trazodone appears to be tolerated better. Further studies with larger samples and double-blind conditions are warranted to confirm our results.

Can we increase speed and efficacy of antidepressant treatments? Part I: General aspects and monoamine-based strategies

Major depressive disorder (MDD) is a severe psychiatric syndrome with high prevalence and socioeconomic impact. Current antidepressant treatments are based on the blockade of serotonin (5-hydroxytryptamine, 5-HT) and/or noradrenaline transporters. These drugs show slow onset of clinical action and limited efficacy, partly due to the activation of physiological negative feed-back mechanisms operating through autoreceptors (5-HT_1A, 5-HT_1B, α₂-adrenoceptors) and postsynaptic receptors (e.g., 5-HT₃). As a result, clinically-relevant doses of reuptake inhibitors increase extracellular (active) 5-HT concentrations in the midbrain raphe nuclei but not in forebrain, as indicated by rodent microdialysis studies and by PET-scan studies in primate/human brain. The prevention of these self-inhibitory mechanisms by antagonists of the above receptors augments preclinical and clinical antidepressant effects. Hence, the mixed ß-adrenoceptor/5-HT_1A antagonist pindolol accelerated, and in some cases enhanced, the clinical action of selective serotonin reuptake inhibitors (SSRI). This strategy has been incorporated into two new multi-target antidepressant drugs, vilazodone and vortioxetine, which combine 5-HT reuptake inhibition and partial agonism at 5-HT_1A receptors. Vortioxetine shows also high affinity for other 5-HT receptors, including excitatory 5-HT₃ receptors located in cortical and hippocampal GABA interneurons. 5-HT₃ receptor blockade by vortioxetine enhances pyramidal neuron activity in prefrontal cortex as well as cortical and hippocampal 5-HT release. It is still too soon to know whether these new antidepressants will represent a real advance over existing drugs in the real world. However, their development opened the way to future antidepressant drugs based on the prevention of local and distal self-inhibitory mechanisms attenuating monoamine activity.

The effects of Psychotropic drugs On Developing brain (ePOD) study: methods and design

BACKGROUND

Animal studies have shown that methylphenidate (MPH) and fluoxetine (FLX) have different effects on dopaminergic and serotonergic system in the developing brain compared to the developed brain. The effects of Psychotropic drugs On the Developing brain (ePOD) study is a combination of different approaches to determine whether there are related findings in humans.

METHODS/DESIGN

Animal studies were carried out to investigate age-related effects of psychotropic drugs and to validate new neuroimaging techniques. In addition, we set up two double-blind placebo controlled clinical trials with MPH in 50 boys (10-12 years) and 50 young men (23-40 years) suffering from ADHD (ePOD-MPH) and with FLX in 40 girls (12-14 years) and 40 young women (23-40 years) suffering from depression and anxiety disorders (ePOD-SSRI). Trial registration numbers are: Nederlands Trial Register NTR3103 and NTR2111. A cross-sectional cohort study on age-related effects of these psychotropic medications in patients who have been treated previously with MPH or FLX (ePOD-Pharmo) is also ongoing. The effects of psychotropic drugs on the developing brain are studied using neuroimaging techniques together with neuropsychological and psychiatric assessments of cognition, behavior and emotion. All assessments take place before, during (only in case of MPH) and after chronic treatment.

DISCUSSION

The combined results of these approaches will provide new insight into the modulating effect of MPH and FLX on brain development.

Citalopram versus other anti-depressive agents for depression

BACKGROUND

Recent US and UK clinical practice guidelines recommend that second-generation antidepressants should be considered amongst the best first-line options when drug therapy is indicated for a depressive episode. Systematic reviews have already highlighted some differences in efficacy between second-generation antidepressants. Citalopram, one of the first selective serotonin reuptake inhibitors (SSRI) introduced in the market, is one of these antidepressant drugs that clinicians use for routine depression care.

OBJECTIVES

To assess the evidence for the efficacy, acceptability and tolerability of citalopram in comparison with tricyclics, heterocyclics, other SSRIs and other conventional and non-conventional antidepressants in the acute-phase treatment of major depression.

SEARCH METHODS

We searched The Cochrane Collaboration Depression, Anxiety and Neurosis Controlled Trials Register and the Cochrane Central Register of Controlled Trials up to February 2012. No language restriction was applied. We contacted pharmaceutical companies and experts in this field for supplemental data.

SELECTION CRITERIA

Randomised controlled trials allocating patients with major depression to citalopram versus any other antidepressants.

DATA COLLECTION AND ANALYSIS

Two reviewers independently extracted data. Information extracted included study characteristics, participant characteristics, intervention details and outcome measures in terms of efficacy (the number of patients who responded or remitted), patient acceptability (the number of patients who failed to complete the study) and tolerability (side-effects).

MAIN RESULTS

Thirty-seven trials compared citalopram with other antidepressants (such as tricyclics, heterocyclics, SSRIs and other antidepressants, either conventional ones, such as mirtazapine, venlafaxine and reboxetine, or non-conventional, like hypericum). Citalopram was shown to be significantly less effective than escitalopram in achieving acute response (odds ratio (OR) 1.47, 95% confidence interval (CI) 1.08 to 2.02), but more effective than paroxetine (OR 0.65, 95% CI 0.44 to 0.96) and reboxetine (OR 0.63, 95% CI 0.43 to 0.91). Significantly fewer patients allocated to citalopram withdrew from trials due to adverse events compared with patients allocated to tricyclics (OR 0.54, 95% CI 0.38 to 0.78) and fewer patients allocated to citalopram reported at least one side effect than reboxetine or venlafaxine (OR 0.64, 95% CI 0.42 to 0.97 and OR 0.46, 95% CI 0.24 to 0.88, respectively).

AUTHORS' CONCLUSIONS

Some statistically significant differences between citalopram and other antidepressants for the acute phase treatment of major depression were found in terms of efficacy, tolerability and acceptability. Citalopram was more efficacious than paroxetine and reboxetine and more acceptable than tricyclics, reboxetine and venlafaxine, however, it seemed to be less efficacious than escitalopram. As with most systematic reviews in psychopharmacology, the potential for overestimation of treatment effect due to sponsorship bias and publication bias should be borne in mind when interpreting review findings. Economic analyses were not reported in the included studies, however, cost effectiveness information is needed in the field of antidepressant trials.

Eco-friendly synthesis and antimicrobial activities of some 1-phenyl-3(5-bromothiophen-2-yl)-5-(substituted phenyl)-2-pyrazolines

Background

Green catalyst fly ash: H₂SO₄ was prepared by mixing fly ash and sulphuric acid. Microwave irradiations are applied for solid phase cyclization of 5-bromo-2-thienyl chalcones and phenyl hydrazine hydrate in the presence of fly ash: H₂SO₄ yields, 1-phenyl-3(5-bromothiophen-2-yl)-5-(substituted phenyl)-2-pyrazolines. These pyrazolines were characterized by their physical constants and spectral data. The antimicrobial activities of all synthesized pyrazolines have been studied.

Results

Scanning electron microscopy (SEM) analysis shows the morphology changes between fly ash and the catalyst fly ash: H₂SO₄. The SEM photographs with the scale of 1 and 50 μm show the fly-ash particle is corroded by H₂SO₄ (indicated by arrow mark), and this may be due to dissolution of fly ash by H₂SO₄. The yields of 1-phenyl-3(5-bromothiophen-2-yl)-5-(substituted phenyl)-2-pyrazolines is more than 75% using this catalyst under microwave heating. All pyrazolines showed moderate activities against antimicrobial strains.

Conclusion

We have developed an efficient catalytic method for synthesis of 1-phenyl-3(5-bromothiophen-2-yl)-5-(substituted phenyl)-2-pyrazolines by solid phase cyclization using a solvent-free environmentally greener catalyst fly ash: H₂SO₄ under microwave irradiation between aryl chalcones and hydrazine hydrate. This reaction protocol offers a simple, economical, environment friendly, non-hazardous, easier work-up procedure, and good yields. All synthesized pyrazoline derivatives showed moderate antimicrobial activities against bacterial and fungal strains.

Response to intravenous antidepressant treatment by suicidal vs. nonsuicidal depressed patients

BACKGROUND

As effects of suicidal status on antidepressant responses remain uncertain, we compared responses to treatment in suicidal and nonsuicidal depressed patients.

METHODS

We evaluated treatment response and covariates in 82 depressed patients diagnosed with DSM-IV major depressive (n=50) or bipolar disorders (n=32) treated initially in a day-hospital for 2 weeks, followed by 4 weeks of outpatient treatment, using citalopram given intravenously and then orally, with or without a mood-stabilizer. Suicidal status was based on an intake score of > or = 3 on item-3 of the 17-item Hamilton Depression Rating Scale, verified by clinical assessment. Morbidity and clinical change were assessed with the remaining 16 items (HDRS(16)).

RESULTS

Suicidal (n=31) and nonsuicidal subjects (n=51) were similar in baseline ratings of depressive symptom-severity but were depressed longer and more likely to abuse substances. Suicidal ratings improved by 36% during 6 weeks of treatment among initially suicidal patients, but other depressive symptoms (HDRS(16)) improved half as much as in nonsuicidal subjects (13.4 vs. 25.1 points), independent of diagnosis, initial illness-severity, and treatment, and half as many patients improved by > or = 20%. In multivariate modeling, only being suicidal predicted poor response.

CONCLUSIONS

Being suicidal may limit response to treatment in depressed major affective disorder patients, independent of diagnosis or overall symptomatic severity.

The Timing of Antidepressant Effects: A Comparison of Diverse Pharmacological and Somatic Treatments

Currently available antidepressants used to treat major depressive disorder (MDD) unfortunately often take weeks to months to achieve their full effects, commonly resulting in considerable morbidity and increased risk for suicidal behavior. Our lack of understanding of the precise cellular underpinnings of this illness and of the mechanism of action of existing effective pharmacological treatments is a large part of the reason that therapies with a more rapid onset of antidepressant action (ROAA) have not been developed. Other issues that need to be addressed include heterogeneous clinical concepts and statistical models to measure rapid antidepressant effects. This review describes the timing of onset of antidepressant effects for various therapies used to treat MDD. While several agents produce earlier improvement of depressive symptoms (defined as occurring within one week), the response rate associated with such agents can be quite variable. These agents include both currently available antidepressants as well as other pharmacological and non-pharmacological interventions. Considerably fewer treatments are associated with ROAA, defined as occurring within several hours or one day. Treatment strategies for MDD whose sustained antidepressant effects manifest within hours or even a few days would have an enormous impact on public health.

Safety and efficacy of oral escitalopram as continuation treatment of intravenous citalopram in patients with major depressive disorder

The objective of this open-label, multicentre study was to evaluate the safety and efficacy of treatment with escitalopram (10 or 20 mg/day) for 6 weeks following a switch from intravenous citalopram treatment (20 or 40 mg/day) in patients presenting with a major depressive episode. A total of 173 patients were included, 147 (85%) of whom completed the study. The mean Montgomery-Asberg Depression Rating Scale (MADRS) total score at inclusion (last citalopram dose) was 31.6 +/- 9.9. The MADRS score decreased to 23.4 +/- 10.5 after 3 days of oral treatment with escitalopram and was 12.7 +/- 9.3 at the end of the study. The scores on the Clinical Global Impression (CGI) and Patient Global Evaluation scales also improved: at the end of the study, the response rates were 67% on the MADRS (defined as >or=50% decrease from MADRS baseline score) and 68% on the CGI-I (defined as CGI-I <or=2). More than half of the patients were in remission (MADRS score <or=12). Overall, the switch from intravenous citalopram to escitalopram was well tolerated. In all, 57 patients (33%) reported at least 1 adverse event, and 7 patients (4%) were withdrawn due to an adverse event. The most frequently reported adverse events were probably linked to residual depressive symptoms (anxiety: 9%; insomnia: 5%). In conclusion, escitalopram was well tolerated as a continuation treatment after switching from intravenous citalopram and reduced depressive symptoms in patients with a moderate to severe major depressive episode.

Intravenous mirtazapine is safe and effective in the treatment of depressed inpatients

Mirtazapine is a third-generation antidepressant with a dual mode of action. The oral administration has been shown to be effective and safe in the treatment of depressed patients. In this multicenter naturalistic study, we assessed the safety, tolerability, and therapeutic efficacy of intravenously administered mirtazapine in 80 moderately to severely depressed inpatients during a treatment period of 14 days. We found a significant decrease of the Hamilton Depression Rating Scale total score compared to baseline. Side effects were mild and transient. Our data indicate that intravenous mirtazapine is an effective, safe and well-tolerated treatment for depressed inpatients.

Transdermal selegiline: the new generation of monoamine oxidase inhibitors

The clinical use of monoamine oxidase inhibitors (MAOIs) has declined due to concerns about food and drug interactions and waning physician experience. Evidence indicates that MAOIs are effective in depressive disorders, in particular depression with atypical features. Efforts to address safety issues have led to the development of more selective and reversible MAOIs, such as moclobemide. Selegiline, a selective monoamine oxidase B inhibitor, has been approved for the adjunctive treatment of Parkinson's disease at low doses. At higher doses, oral selegiline is also effective in major depressive disorder (MDD) but loses its selectivity and has the potential for tyramine interactions. To overcome these problems, a transdermal formulation of selegiline, the selegiline transdermal system (STS), was developed with novel pharmacokinetic and pharmacodynamic properties. Compared with oral administration, transdermal selegiline leads to sustained plasma concentrations of the parent compound, increasing the amount of drug delivered to the brain and decreasing metabolite production. In addition, STS allows targeted inhibition of central nervous system monoamine A (MAO-A) and monoamine B isoenzymes with minimal effects on MAO-A in the gastrointestinal and hepatic systems, thereby reducing the risk of interactions with tyramine-rich foods (the "cheese-reaction"). Clinical trials have found 6 mg/24 hours of STS to be effective in MDD without the need for dietary restrictions. The efficacy and safety profile of STS supports its use in MDD. It is possible that STS may demonstrate benefit in MDD with atypical features or MDD resistant to other antidepressants. However, more research is needed. Clinicians should familiarize themselves with the properties and indications for the new generation of MAOIs.

Tolérance et efficacité de l’escitalopram per os, en relais de la forme intraveineuse du citalopram chez des patients présentant un épisode dépressif majeur

Intravenous (iv) administration of an antidepressant is a common practice in some European countries, particularly in France, Spain, and Italy in the initial treatment phase of hospitalised, severe depressed patients. After a beneficial response is observed, patients are switched to an oral formulation. The approved treatment period of the iv form of citalopram is limited to 8-10 days. The high bioavailability of citalopram permits the use of identical iv and oral doses. Citalopram is a racemate, consisting of a 1:1 mixture of the S- and R-enantiomers. The therapeutically active component is the S-enantiomer (escitalopram). Pharmacokinetic single dose administration studies in healthy subjects have demonstrated that daily oral administration of 20 mg of escitalopram or 40 mg citalopram results in similar plasma concentrations of the S-enantiomer of citalopram. This open-label multicentre French prospective study investigated the tolerability and efficacy of oral escitalopram 10 and 20 mg/day, administered for a 6-week period as continuation treatment of citalopram (20 mg or 40 mg daily) intravenous (iv), in patients with Major Depressive Disorder. A total of 171 patients were enrolled, of whom 147 (85%) completed the study. The mean MADRS score at inclusion (last citalopram dose) was 31.6 +/- 9.9. The total MADRS score decreased after 3 days of oral treatment with escitalopram. Escitalopram demonstrated a continuous effect in treating depressive symptoms throughout the study. The decrease in MADRS mean total score from baseline was statistically significant to each visit (day 3, 15; p < 0.0001). At final visit (J42), the decrease was - 18.9 +/- 11.7 (p < 0.0001) and the MADRS mean total score was 12.7 +/- 9.3. There were no differences seen in the patient response comparing gender, age, and the single or recurrent episodes. The changes of Clinical Global Impression scores (CGI-S, CGI-I, PGE-Patient Global Evaluation) were also indicative of an improvement of the patients' depression. The CGI-I and PGE scores were significantly correlated indicating good agreement between investigator and patient in rating the degree of improvement. At the end of the study, 67% of patients were classified as responders (decrease of MADRS score from baseline > or = 50%), and the majority of them were considered remitters (final MADRS score < or = 12). Overall, the switch from intravenous citalopram to oral escitalopram was well tolerated in the study population. In all, 57 patients (33%) reported at least one adverse event (AE) during the study (21 patients in the 10 mg group and 36 patients in the 20 mg group); of these, 7 patients (4%) withdrew from the study. The most frequently reported AEs were suggestive of residual symptoms of depression (anxiety, 9%; insomnia, 5% of patients). In conclusion, in this study oral escitalopram (10 mg or 20 mg) was well tolerated as continuation treatment after switching from intravenous citalopram (20 mg or 40 mg). From the efficacy and safety data of this study, it can be concluded that the switch from citalopram iv to oral escitalopram (10 and 20 mg/day) is effective in decreasing depressive symptoms, and could be safely proposed in patients with major depressive disorder.

Neuroendocrine response to intravenous citalopram in healthy control subjects: pharmacokinetic influences

RATIONALE

The neuroendocrine response to intravenous citalopram may provide an acute, functional, in vivo measure of the neural serotonin (5-HT) system.

OBJECTIVE

To refine the quantification of acute neuroendocrine responses following intravenous citalopram in studies of 5-HT function.

METHODS

In 75 adult healthy subjects taking part in four similar protocols, we measured plasma prolactin and cortisol, as well as serial citalopram concentrations following intravenous citalopram (10 mg, 20 mg, 40 mg, 0.33 mg/kg) and placebo. The relationship between the AUC for intravenous citalopram during the first 150 min (AUC(150)) and the magnitude of the neuroendocrine response was determined. The role of pharmacokinetic (PK) parameters, as well as sensitivity to placebo injections, in influencing the neuroendocrine response to citalopram was then evaluated.

RESULTS

Citalopram produced a dose-dependent increase in cortisol and prolactin. The maximal increase from baseline correlated significantly but modestly with citalopram's AUC(150) (prolactin r(2)=0.23, P<0.0001; cortisol r(2)=0.3, P<0.0001). Additionally, citalopram's AUC(150) was affected by between-subject differences in both the peripheral and central volume of distribution. However, the neuroendocrine responses to citalopram did not correlate with the responses to placebo.

CONCLUSIONS

The parenteral citalopram challenge test is characterized by a modest concentration-response relationship, with concentration influenced by variable PK factors. Accounting for individual differences in drug distribution may improve the power of the citalopram challenge test, when used as an in vivo measure of central 5-HT function.

Serotonin modulation of cerebral blood flow measured with positron emission tomography (PET) in humans

To develop a method to measure the dynamic response of the serotonin system in vivo, the effects of intravenously administered citalopram (the most selective of the serotonin reuptake inhibitors) or clomipramine on cerebral blood flow (CBF) were evaluated. CBF was measured with positron emission tomography (PET) in 27 normal subjects scanned under baseline conditions and, on the same day, after an intravenous (IV) infusion of placebo, citalopram, or clomipramine using a randomized, double-blind design. The main effects of the drugs on blood flow occurred in the thalamus, hypothalamus, and cingulate cortex. Compared to placebo, clomipramine reduced blood flow in the mediodorsal and ventral lateral nuclei of the thalamus, whereas citalopram reduced blood flow in the pulvinar nucleus and the hypothalamus. Compared to clomipramine, citalopram decreased blood flow in the cingulate cortex. The findings support previous reports showing acute central effects of citalopram and clomipramine on regional serotonergic functions measured by PET. Acute side effects may, however, require that care is taken in the selection of experimental designs for future PET studies using IV administration of these antidepressants.

Intravenous antidepressants: a review

Antidepressant medications have an onset of action of several weeks and have moderate efficacy. Their mode of administration is oral (p.o.). Some clinicians wondered whether intravenous (i.v.) administration would speed onset of action and increase efficacy. In this article we review controlled studies on i.v. administration of antidepressants. These include clomipramine, citalopram, and other antidepressants. Overall these studies do not support increased efficacy of i.v. over p.o.administration but there are suggestions of a faster onset of action. In one study i.v. citalopram showed superior response rates over p.o. citalopram (79% vs. 63%) in severely depressed patients at 8 weeks.

New formulations of existing antidepressants: advantages in the management of depression

For nearly 50 years, antidepressant drugs have been the first-line treatment for various forms of depression. Despite their widespread use, these medications have significant shortcomings, in particular problems of patient compliance due to adverse effects. The introduction of new formulations of existing antidepressant medications may provide patients with benefits in terms of convenience of use. As a consequence, improvements in compliance may lead to better antidepressant efficiency.An orally disintegrating formulation of mirtazapine (mirtazapine SolTab), a once-weekly formulation of fluoxetine, an enantiomer-specific formulation of citalopram (escitalopram), an extended-release formulation of venlafaxine (venlafaxine XR), a controlled-release formulation of paroxetine (paroxetine CR) and intravenous formulations of some of the newer antidepressants have all been evaluated in limited clinical trials. In this article, a review of the pharmacokinetics and clinical evaluations of these formulations is presented. While there do not appear to be major clinical advantages for the new formulations in terms of antidepressant efficacy, none of them is less efficacious than their older counterpart. Indeed, some of the new formulations are more acceptable to patients (fluoxetine once-weekly, paroxetine CR), others have pharmacokinetic advantages (venlafaxine XR, paroxetine CR), while others may have a faster onset of effect (mirtazapine SolTab, intravenous formulations). Further evaluation of some formulations is still required (mirtazapine SolTab, fluoxetine once-weekly), while others (venlafaxine XR, escitalopram) are finding widespread acceptance in clinical practice.

Intravenous mirtazapine in the treatment of depressed inpatients

Mirtazapine is a novel antidepressant with a noradrenergic and specific serotonergic mode of action. So far, mirtazapine has been administered orally. This naturalistic study evaluates the antidepressant efficacy, safety, and tolerability of mirtazapine 15 mg/day administered intravenously to 27 inpatients with moderate to severe major depression. Compared with baseline, we found a significant decrease of the Hamilton Depressive Rating Scale (HDRS) total score (P<0.001). Side effects were mild and transient. Altogether, the results of this preliminary study show that intravenous mirtazapine is an effective, safe and well tolerated treatment for depressed inpatients.