Sustained response to open-label venlafaxine in drug-resistant major depression

Long-term Safety and Efficacy of Esketamine Nasal Spray Plus an Oral Antidepressant in Patients with Treatment-resistant Depression- an Asian Sub-group Analysis from the SUSTAIN-2 Study

Objective

To evaluate the long-term safety and efficacy of intranasal esketamine in patients with treatment-resistant depression from the Asian subgroup of the SUSTAIN-2 study.

Methods

SUSTAIN-2 was a phase 3, open-label, single-arm, multicenter study comprising a 4-week screening, 4-week induction, 48-week optimization/maintenance, and 4-week follow-up (upon esketamine discontinuation) phase. Patients with treatment-resistant depression received esketamine plus an oral antidepressant during the treatment period.

Results

The incidence of ≥ 1 serious treatment-emergent adverse event (TEAE) among the 78 subjects from the Asian subgroup (Taiwan 33, Korea 26, Malaysia 19) was 11.5% (n = 9); with no fatal TEAE. 13 Asian patients (16.7%) discontinued esketamine due to TEAEs. The most common TEAEs were dizziness (37.2%), nausea (29.5%), dissociation (28.2%), and headache (21.8%). Most TEAEs were mild to moderate in severity, transient and resolved on the same day. Upon discontinuation of esketamine, no trend in withdrawal symptoms was observed to associate long-term use of esketamine with withdrawal syndrome. There were no reports of drug seeking, abuse, or overdose. Improvements in symptoms, functioning and quality of life, occurred during in the induction phase and were generally maintained through the optimization/maintenance phases of the study.

Conclusion

The safety and efficacy of esketamine in the Asian subgroup was generally consistent with the total SUSTAIN-2 population. There was no new safety signal and no indication of a high potential for abuse with the long-term (up to one year) use of esketamine in the Asian subgroup. Most of the benefits of esketamine occurred early during the induction phase.

Effect of Sleep Disturbance on Efficacy of Esketamine in Treatment-Resistant Depression: Findings from Randomized Controlled Trials

PURPOSE

To evaluate the relationship of sleep disturbance to the antidepressant effects of esketamine.

MATERIALS AND METHODS

Two double-blind, 4-week studies randomized adults with treatment-resistant depression (TRD) to placebo or esketamine nasal spray, each with newly initiated antidepressant. Sleep was assessed using Montgomery-Åsberg Depression Rating Scale (MADRS) item 4. Change in response (≥50% decrease in MADRS total score) and remission (total MADRS score ≤12) at day 28 was examined by presence/absence of baseline sleep disturbance using logistic regression models. Impact on reported sleep disturbance (MADRS item 4 score) was examined using ANCOVA models.

RESULTS

At baseline, most patients reported disturbed sleep - moderate/severe (65.3%, 369/565), mild (25.3%, 143/565), or none/slightly (9.4%, 53/565) - with similar distribution between treatment groups. A higher proportion of esketamine-treated patients achieved response (OR = 2.05; 95% CI: 1.40-3.02; P < 0.001) and remission (OR = 1.81; 95% CI: 1.23-2.66; P = 0.003) at day 28 compared to antidepressant plus placebo, regardless of presence/severity of sleep disturbance. Consistent with this, sleep (MADRS item 4 score) improved in both groups after the first dose, more so with esketamine by day 8 (between-group difference: P ≤ 0.02 at all time points). Across both treatment groups, 1-point improvement in sleep at day 8 increased the probability of antidepressant response on day 28 by 26% (OR = 1.26, 95% CI: 1.12-1.42; P < 0.001), and remission by 28% (OR = 1.28, 95% CI: 1.14-1.43; P < 0.001).

CONCLUSION

Antidepressant efficacy of esketamine was demonstrated in patients with TRD, regardless of the presence of sleep disturbance. After 8 days of treatment and thereafter, significantly more esketamine-treated patients reported improvement in sleep versus antidepressant plus placebo.

Exploring venlafaxine pharmacokinetic variability with a phenotyping approach, a multicentric french-swiss study (MARVEL study)

Background

It is well known that the standard doses of a given drug may not have equivalent effects in all patients. To date, the management of depression remains mainly empirical and often poorly evaluated. The development of a personalized medicine in psychiatry may reduce treatment failure, intolerance or resistance, and hence the burden and costs of mood depressive disorders.

The Geneva Cocktail Phenotypic approach presents several advantages including the “in vivo” measure of different cytochromes and transporter P-gp activities, their simultaneous determination in a single test, avoiding the influence of variability over time on phenotyping results, the administration of low dose substrates, a limited sampling strategy with an analytical method developed on DBS analysis.

The goal of this project is to explore the relationship between the activity of drug-metabolizing enzymes (DME), assessed by a phenotypic approach, and the concentrations of Venlafaxine (VLX) + O-demethyl-venlafaxine (ODV), the efficacy and tolerance of VLX.

Methods/design

This study is a multicentre prospective non-randomized open trial. Eligible patients present a major depressive episode, MADRS over or equal to 20, treatment with VLX regardless of the dose during at least 4 weeks. The Phenotype Visit includes VLX and ODV concentration measurement.

Following the oral absorption of low doses of omeprazole, midazolam, dextromethorphan, and fexofenadine, drug metabolizing enzymes activity is assessed by specific metabolite/probe concentration ratios from a sample taken 2 h after cocktail administration for CYP2C19, CYP3A4, CYP2D6; and by the determination of the limited area under the curve from the capillary blood samples taken 2–3 and 6 h after cocktail administration for CYP2C19 and P-gp.

Two follow-up visits will take place between 25 and 40 days and 50–70 days after inclusion. They include assessment of efficacy, tolerance and observance.

Eleven french centres are involved in recruitment, expected to be completed within approximately 2 years with 205 patients. Metabolic ratios are determined in Geneva, Switzerland.

Discussion

By showing an association between drug metabolism and VLX concentrations, efficacy and tolerance, there is a hope that testing drug metabolism pathways with a phenotypical approach would help physicians in selecting and dosing antidepressants. The MARVEL study will provide an important contribution to increasing the knowledge of VLX variability and in optimizing the use of methods of personalized therapy in psychiatric settings.

Trial registration

ClinicalTrials.govNCT02590185 (10/27/2015). This study is currently recruiting participants.

What to expect from a third step in treatment resistant depression: A prospective open study on escitalopram

OBJECTIVES

Only few studies investigated treatment strategies for treatment resistant depression (TRD). The objective of this multicentre study was to evaluate TRD patients who did not respond to at least two antidepressants.

METHODS

A total of 417 patients, who failed to respond to a previous retrospectively assessed antidepressant (AD1), were firstly included in a 6-week venlafaxine treatment (AD2); secondly, those who failed to respond were treated for further 6 weeks with escitalopram (AD3).

RESULTS

Out of 417 patients who had failed to respond to previous treatment (AD1), 334 completed treatment with venlafaxine to prospectively define TRD. In the intent to treat (ITT) population in the first phase of the trial (AD2), responders to venlafaxine were 151 (36.21%) out of which remitters were 83 (19.90%). After phase one, 170 non-responders, defined as TRD, were included in the second phase and 157 completed the course. Of the 170 ITT entering the second phase (AD3), responders to escitalopram were 71 (41.76%) out of which remitters were 39 (22.94%). After the third treatment, patients showed a dropout rate of 7.65% and a rate of presence of at least one serious adverse event of 19.18%.

CONCLUSIONS

Relevant rates of response and remission may be observed after a third line treatment in patients resistant to two previous treatments. A relevant limitation of this study was represented by the design: naturalistic, non-randomized, open-label, without a control sample and with unblinded raters.

A 10-month, open-label evaluation of desvenlafaxine in outpatients with major depressive disorder

BACKGROUND

The primary objective was to evaluate the long-term safety of desvenlafaxine (administered as desvenlafaxine succinate) during open-label treatment in adult outpatients with a primary DSM-IV diagnosis of major depressive disorder (MDD).

METHOD

Depressed adult outpatients (≥ 18 years) who had completed 8-week, double-blind therapy (desvenlafaxine, venlafaxine extended release, or placebo) in a phase 3 study of desvenlafaxine for MDD received up to 10 months of open-label treatment with flexible-dose desvenlafaxine (200 to 400 mg/d). Safety assessments included physical examination, measurement of weight and vital signs, laboratory determinations, and 12-lead electrocardiogram recordings. Adverse events (AEs) and discontinuations due to AEs were monitored throughout the trial. The primary efficacy outcome was mean change from baseline on 17-item Hamilton Depression Rating Scale (HDRS-17) total score. The trial was conducted from August 2003 to March 2006.

RESULTS

The safety population included 1,395 patients who took at least 1 dose of open-label desvenlafaxine. Treatment-emergent AEs were reported by 1,238 of 1,395 patients (89%) during the open-label, on-therapy period. Treatment-emergent AEs reported by 10% or more patients were headache, nausea, hyperhidrosis, dizziness, dry mouth, insomnia, upper respiratory infection, nasopharyngitis, and fatigue. Adverse events were the primary reason for study discontinuation in 296 of 1,395 patients (21%). Ten patients (< 1%) had serious AEs that were considered possibly, probably, or definitely related to the study drug during the on-therapy period. No deaths occurred during the study.

CONCLUSIONS

Desvenlafaxine can be safely administered for up to 12 months. No new safety findings were observed in this study.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT01309542.

Introduction: selecting an antidepressant

Four years ago, my colleagues and I published an article titled “Why isn't bupropion the most frequently prescribed antidepressant?” The goal of that article was not to advocate bupropion as the preferred agent for treating depression, but rather to stimulate discussion about how psychiatrists choose an antidepressant as well as to highlight the gap between results of efficacy studies and clinical decision making in real-world practice.

The argument in support of bupropion being the preferred antidepressant was based on three premises: all antidepressants are equally effective; adverse effects (AEs) of greatest concern to patients who take antidepressants are weight gain and sexual dysfunction; and bupropion does not cause either of these AEs. Acceptance of these three premises suggested the title of that article.

Although many reviews of the antidepressant literature, including the revised American Psychiatric Association Practice Guideline for the Treatment of Major Depressive Disorder, conclude that antidepressants are equally effective in general, several experts in the treatment of depression have suggested that medications with >1 mechanism of action may be more effective than agents that have more selective neurotransmitter effects. In a meta-analysis of eight studies comparing the remission rates in patients treated with the serotonin-norepinephrine reuptake inhibitor (SNRI) venlafaxine or selective serotonin reuptake inhibitors (SSRIs), Thase and colleagues demonstrated that venlafaxine was more effective than SSRIs in achieving remission in depressed patients. However, these conclusions were tentative as most of the included studies were comparisons of venlafaxine and fluoxetine; only one study included sertraline, and there were no studies of citalopram included in the review. In addition, patients who had previously failed treatment with an SSRI were not excluded, and, although patients who fail with one SSRI may respond to subsequent treatment with another SSRI, the inclusion of SSRI failures may favor venlafaxine in comparisons with SSRIs. Lastly, all of the studies included in the meta-analysis were funded by the manufacturer of venlafaxine.

Drug treatment of depression in the 2000s: An overview of achievements in the last 10 years and future possibilities

During the past 10 years our knowledge about the pharmacotherapy of depression has been consolidated, and a variety of very interesting new compounds launched onto the market. The pipeline of the pharmaceutical industry is still filled with an assortment of new developments and very promising new approaches towards the pharmacotherapy of depressive disorders. Future pharmacological treatments of depression will not only enhance serotonergic and noradrenergic neurotransmission: other systems, such as the melatonergic receptor system and the hypothalamus-pituitary-adrenal axis, are also the targets of newly developed and upcoming substances with putative antidepressant effects. The main advantages of the currently available newer pharmacotherapeutic options are the broadening of the spectrum of possible antidepressant treatments, which is of particular importance for the growing number of patients suffering from difficult-to-treat depression, and a far better tolerability profile in comparison to older compounds such as tricyclic antidepressants. Unresolved issues are the unacceptably high rate of non-responsiveness during antidepressant treatment, a latency of sometimes several weeks until clinical improvement and remission can be achieved, and a variety of possible side effects also present during treatment with modern compounds. This review mainly presents the development of antidepressant pharmacotherapies during the past 10 years, together with pharmacokinetic and pharmacodynamic information and a comparison of different pharmacological treatment principles evaluated in randomized controlled clinical trials. In addition, new pharmacological strategies that are not yet available on the market and strategies currently under development are reviewed in detail. The study of new treatment options is of major importance to provide better strategies for the clinical management of depression in the future, and is thus also of great socio-economic importance.

A randomized, double-blind comparison of olanzapine/fluoxetine combination, olanzapine, fluoxetine, and venlafaxine in treatment-resistant depression

Based on preliminary evidence of its usefulness in treatment-resistant depression (TRD), an olanzapine/fluoxetine combination (OFC) was examined in comparison with olanzapine, fluoxetine, and venlafaxine in a TRD population. In this 12-week double-blind study, 483 subjects with unipolar, nonpsychotic TRD, with historic failure on a selective serotonin reuptake inhibitor (SSRI) and prospective failure on open-label venlafaxine, were randomized to an OFC or to an olanzapine, fluoxetine, or venlafaxine monotherapy group. Venlafaxine was continued randomly in the double-blind acute phase to explore the benefits of continuation versus switching therapy. The Montgomery-Asberg Depression Rating Scale (MADRS) total change score at end point was the primary outcome measure. The OFC group had significantly greater improvement in depressive symptoms by week 1 of treatment (MADRS mean change =-7.2, baseline =29.6), in comparison to olanzapine (-4.8, P=.03), fluoxetine (-4.7, P=.03), or venlafaxine (-3.7, P=.002) groups and maintained its statistical separation from all three monotherapy groups through week 6. At end point, the OFC group was significantly different only from the olanzapine group (-14.1 vs. -7.7, P<.001). Analysis of a subgroup of subjects who had an SSRI failure in their current depressive episode (n=334) revealed statistical separation from both olanzapine and fluoxetine (but not venlafaxine) at end point: OFC (-14.6) versus olanzapine (-9.4, P<.001) versus fluoxetine (-10.7, P=.006) versus venlafaxine (-14.7, P=.98). The OFC had a safety profile comparable to its component monotherapies (i.e., olanzapine and fluoxetine), showed a rapid onset of antidepressant effect, and was effective in this TRD sample. At the study end point, OFC, fluoxetine, venlafaxine, and low-dose OFC all appeared to be similarly effective.

Treatment with venlafaxine extended release after SSRI nonresponse or intolerance: a randomized comparison of standard- and higher-dosing strategies

OBJECTIVE

Evaluate efficacy of standard and higher doses of venlafaxine extended release (ER) in depressed outpatients who had either not responded to or could not tolerate an adequate trial of therapy with a selective serotonin reuptake inhibitor (SSRI).

METHODS

Outpatients (n = 232) with major depressive disorder were randomly assigned to 8 weeks of treatment with either "standard" (n = 119; mean dose = 148 mg/d) or "higher" (n = 113; mean dose = 309 mg/d) dosage therapies. Between weeks 8 and 12, nonresponders in the standard dose group could receive higher dose therapy.

RESULTS

Response rates in the higher dose group were significantly greater at week 8 on the Clinical Global Impressions-Improvement scale (68% vs 52%; P < 0.001) and Patient Global Impressions scale (intent-to- treat; 68% vs 52%; P < 0.001). The dosing strategies did not, however, differ significantly in change in HAM-D21 total score or HAM-D21 response or remission rates. At week 12, there were no significant efficacy differences between the two groups in the intent-to-treat sample. Five side effects (constipation, sweating, hypertension, agitation, and urinary frequency) were more common in the high-dose group.

CONCLUSIONS

Higher dose therapy with venlafaxine ER (ie, 300-375 mg/d) resulted in a more rapid response on some measures, but was not as well tolerated as therapy at standard doses. Although these data provide further evidence of a dose-response relationship for venlafaxine therapy results suggest that slower titration to higher doses of venlafaxine ER may improve tolerability without greatly diminishing the probability of success.

Duloxetine: A Dual Serotonin-Norepinephrine Reuptake Inhibitor for Treatment of Major Depressive Disorder

The burden of mental illness has been underestimated worldwide. Depression was the fourth leading cause of disease burden in the world in 1990 and is projected to be the second leading cause of disability by 2020. It is a leading cause of morbidity and mortality in the United States, costing billions of dollars annually in direct and indirect medical costs and losses in productivity. Patients with major depressive disorder (MDD) may experience both psychological and medical complaints, including somatic sensations or pain. Some antidepressants have been shown to treat chronic pain syndromes, but despite the variety of antidepressants available in the United States, only 65-70% of patients respond to initial antidepressant treatment. Treatments are limited by delayed onset of antidepressant effects, side effects, partial response, and treatment resistance. Duloxetine, approved by the U.S. Food and Drug Administration for the treatment of MDD, is a reuptake inhibitor at serotonergic and noradrenergic neurons and appears to have low affinity for other neurotransmitter systems. In clinical trials, duloxetine was effective for the treatment of MDD and was well tolerated. Further study is needed to compare its efficacy with that of other antidepressants, to clarify effects on somatic symptoms, and to assess potential adverse cardiovascular and sexual side effects. Duloxetine is also approved for the management of diabetic peripheral neuropathic pain and is under investigation for the treatment of stress urinary incontinence in women.

Therapeutic alternatives for difficult-to-treat depression: a narrative review of the state of the evidence

Despite the large number of depressed patients who do not respond to first-line antidepressants, the evidence base of alternate strategies is quite thin. In this article, a simple 5-stage system for categorizing treatment-resistant depression (TRD) is described and the evidence pertaining to the major strategies currently utilized is summarized using four grades, ranging from D (case reports only) to A (multiple positive placebo-controlled trials). It is concluded that the level of evidence supporting many of the contemporary strategies used for TRD (eg, combinations of antidepressants and augmentation with medications such as pindolol, buspirone, or modafinil) is scanty at best. Even the fundamental question concerning "to augment or to switch" is not answerable with available data. It is noted that the best-documented treatments (ie, lithium augmentation, switching to a monoamine oxidase inhibitor, and electroconvulsive therapy) are among the least utilized. This state of affairs will improve with completion of the studies of Systematic Treatment Alternatives to Relieve Depression, a large multicenter study of difficult-to-treat depression funded by the National Institute of Mental Health. There is a need for greater collaboration among academicians and organizations, such as the American Psychiatric Association, the National Institute of Mental Health, and the pharmaceutical industry, to ensure that sufficient research is conducted so that clinician's choices for patients with TRD can be guided by empirical evidence.

Derivation of a definition of remission on the Montgomery-Asberg depression rating scale corresponding to the definition of remission on the Hamilton rating scale for depression

During the past decade the Montgomery-Asberg Depression Rating Scale (MADRS) has been used with increasing frequency to measure outcome in antidepressant efficacy trials (AETs). In characterizing treatment outcome in AETs it is common to define treatment remission as a score below a predetermined cutoff score on the scale. Various cutoffs have been used to define remission on the MADRS. The goal of the present paper is to determine the cutoff on the MADRS that most closely corresponds to the cutoff most frequently used on the Hamilton Rating Scale for Depression to define remission. Three hundred and three psychiatric outpatients who were being treated for a DSM-IV major depressive episode were rated on the HRSD and the MADRS. A linear regression equation was computed to estimate MADRS scores from HRSD scores. After deriving the regression equation, we computed the MADRS score corresponding to an HRSD score of 7. We also examined the sensitivity, specificity and overall classification rate of the MADRS for identifying remission on the HRSD. Based on the equation from a linear regression analysis for the entire sample, a MADRS score of </=11 would correspond to a score of </=7 on the HRSD. We repeated the analysis after excluding the more severely depressed patients who currently met criteria for MDD, and based on the equation from this regression analysis a MADRS score of </=10 would correspond to a score of </=7 on the HRSD. In a complementary analysis, we examined the sensitivity, specificity and overall classification rate of the MADRS at different cutoff points for identifying remission, and found that a cutoff of </=10 maximized the level of agreement with the HRSD definition of remission. In conclusion, the regression equation relating HRSD and MADRS scores is dependent, in part, on the range and severity of scores in the sample. To facilitate comparisons of studies using the HRSD and MADRS our results suggest that a cutoff of 10 on the MADRS is equivalent to the HRSD cutoff of 7.

A review of studies of the Hamilton depression rating scale in healthy controls: implications for the definition of remission in treatment studies of depression

The Hamilton Rating Scale for Depression (HRSD) is the most commonly used symptom severity scale to evaluate the efficacy of antidepressant treatment. On the basis of an expert consensus panel, an HRSD score of < or = 7 was recommended as a cutoff to define remission. Since that recommendation, little empirical work has been conducted to confirm the validity of this threshold. One approach toward determining a cutoff score for defining remission is to establish the range of values for healthy controls. We therefore conducted a literature review of studies of the HRSD in healthy controls to determine the normal range of values. Studies of the HRSD in healthy control groups were identified in two ways. First, a MEDLINE search for the years 1966 to 2002 was conducted using the key words Hamilton, depression, and controls, and articles were reviewed. Second, the 69 studies included in two review articles written by the authors were examined. We identified 27 studies that included data on the HRSD for 1014 healthy controls. Across all studies, the weighted mean (SD) HRSD score, adjusting for sample size, was 3.2 (3.2; 95% CI, 3.0 to 3.4). HRSD scores were similar in geriatric and nongeriatric samples, and in men and women. Because HRSD scores in healthy controls are more likely to follow a skewed than a normal distribution, based on a mean of 3.2 and a SD of 3.2, at least 84% of healthy controls scored 7 or less on the HRSD, and 97.5% scored 10 or less. Thus, these results can be taken as support for the recommended cutoff of 7 on the HRSD to define remission. The results can also be used for normative comparisons in which posttreatment group mean scores are compared with mean scores from normative samples.

Extended-release venlafaxine in relapse prevention for patients with major depressive disorder

Many studies have demonstrated that venlafaxine is an efficacious and safe treatment for major depressive disorder (MDD). This double-blind, placebo-controlled study was performed to evaluate the efficacy of venlafaxine extended-release (XR) (75-225 mg/day) in the prevention of relapse of depression. Patients with MDD who responded to an 8-week course of venlafaxine XR treatment, i.e., had a score < or = 3 on the Clinical Global Impressions scale-Severity of Illness item (CGI-S) and a 21-item Hamilton Rating Scale for Depression (HAM-D(21)) score < or = 10, were randomly assigned to receive continuation treatment (up to 6 months) with venlafaxine XR (n=161) or placebo (n=157). The main efficacy outcome measure was the number of patients who experienced a relapse of depression. Relapse was defined by either a combination of a patient meeting Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria for MDD and a CGI-S score > or = 4, two consecutive CGI-S scores > or = 4, or a final CGI-S score > or = 4 for a patient who withdrew from the study. The cumulative probability of relapse was calculated using the Kaplan-Meier method of survival analysis. During the 6-month evaluation period, significantly more patients in the placebo group had a relapse of MDD than did patients who continued treatment with venlafaxine XR. Cumulative relapse rates at 3 and 6 months were 19 and 28%, respectively, for venlafaxine XR, and 44 and 52%, respectively, for placebo. This study demonstrates that venlafaxine XR is an effective and safe continuation therapy.

A review of studies of the Montgomery-Asberg Depression Rating Scale in controls: implications for the definition of remission in treatment studies of depression

The Montgomery-Asberg Depression Rating Scale (MADRS) is one of the most commonly used symptom severity scales to evaluate the efficacy of antidepressant treatment Various cut-offs have been employed in antidepressant efficacy trials to define remission, although little empirical work has been carried out to determine the validity of various thresholds. One approach towards deriving a valid cut-off score for defining remission is to determine whether a patient's level of symptoms falls within the normal range of values after treatment We therefore conducted a literature review of studies of the MADRS in healthy controls to determine the normal range of values. We identified 10 studies of 14 samples that included data on the MADRS for 569 controls. Across all studies, the mean (+/- SD) weighted MADRS score, adjusting for sample size, was 4.0 (5.8) (95% confidence interval 3.5-4.5). These results are consistent with the findings of our study of the validity of different cut-offs to define remission on the MADRS-based on a narrow definition of remission, which required a complete absence of clinically significant symptoms of depression, the optimal MADRS cut-off was < or = 4 whereas based on a broader definition, the optimal cut-off was < or = 9. The findings can be used for normative comparisons in which post-treatment group mean scores are compared to mean scores from normative samples. A limitation of the review is that none of the studies was based on a randomly selected sample from the general population. In addition, the rigor of the screening used to exclude individuals with psychopathology in most studies is unknown; thus, some of the controls may have had diagnosable depression, thereby elevating the mean scores in the presumptively healthy control group.

Time course of clinical response to venlafaxine: relevance of plasma level and chirality

OBJECTIVE

Early clinical response to antidepressant treatment is an important therapeutic goal, considering the psychological, social and economic consequences of depression. The aim of the present study was to investigate the relationship between the time course of response and the concentration of venlafaxine (V), its active metabolite O-desmethylvenlafaxine (ODV) and enantiomeric ratios V(+)/V(-) and ODV(+)/ODV(-).

METHODS

Depressed inpatients ( n=35) received V orally at a fixed 300 mg daily dose. Accepted comedication included clorazepate (maximum 60 mg/day), zopiclone (maximum 15 mg/day) and low-dose trazodone (maximum 200 mg/day). Severity of depression was assessed on days 0, 4, 7, 11, 14, 21 and 28 (Montgomery and Asberg Depression Rating Scale). Blood samples were taken on day 14 and day 28 and submitted to stereoselective determination. All measurements reflected trough steady-state values. First, pattern analysis was used to provide a categorical perspective of clinical response (50% improvement from baseline depression score). Patients displaying non-response, transient response, early persistent response and delayed persistent response were compared with respect to racemic concentrations and enantiomeric ratios. Second, in a dimensional perspective, mixed-effects modelling was used to analyse severity of depression versus time curves with respect to the possible influence of concentrations and enantiomeric ratios.

RESULTS

Comparison of patients with and without persistent response did not reveal any significant difference for V, ODV, V+ODV plasma levels or enantiomeric ratios. Persistent response was significantly associated with less frequent pre-study antidepressant medication and less frequent comedication with zopiclone (day 14) and clorazepate (day 28) during the study. Focus on patients with persistent response ( n=19, 54.3%) indicated that early response, first observed before day 14, was associated with significantly higher V+ODV concentration than delayed response (median 725 ng/ml versus 554 ng/ml, P=0.023). No difference was found for pre-study medication or comedication during the study. Shorter time to onset of response was significantly associated with lower V(+)/V(-) enantiomeric ratio (r(s)=0.48, P<0.05). Mixed-effects modelling of depression severity versus time curves in patients with persistent response confirmed that either higher V+ODV plasma level or lower V(+)/V(-) ratio were significantly associated with more rapid decrease of depression score (likelihood ratio tests, P=0.012 and P=0.046, respectively).

CONCLUSION

Considering its modest sample size, naturalistic design and limited observation period, the present study provided preliminary indication that earlier clinical response may occur with higher V+ODV plasma level, extending previous dose-response studies. The hypothesis was also raised that exposure to a more potent noradrenergic therapeutic moiety, as reflected by a lower V(+)/V(-) ratio, may be relevant to early improvement of depression.

Venlafaxine: A 2003 update

BACKGROUND

venlafaxine has been available for use as an antidepressant in the United States for a decade.

OBJECTIVE

Comprehensive reviews of venlafaxine have been published elsewhere; thus, this update focuses on newer issues of treatment remission in depression, treatment-resistant depression, and extended-release venlafaxine for generalized anxiety disorder (GAD).

METHODS

Relevant clinical literature from 1993 through 2003 was identified from database searches of MEDLINE and International Pharmaceutical Abstracts, and from manual searches of reference lists of the identified papers. Search terms included venlafaxine extended-release, venlafaxine XR, treatment-resistant depression, depressive disorders, anxiety disorders, generalized anxiety disorder, and antidepressive agents second generation.

RESULTS

With its dual action of serotonin and noradrenergic reuptake inhibition, venlafaxine has been shown to be superior in efficacy to selective serotonin reuptake inhibitors for severe major depressive disorder, treatment-resistant depression, and depressive symptom remission. Its demonstrated efficacy for both short- and long-term treatment of GAD has led to its use for obsessive-compulsive disorder and chronic pain syndromes, although inadequate clinical literature currently exists to support these latter 2 uses. In the past decade, no new or unexpected adverse events have been identified with venlafaxine therapy, except a possibly greater risk of fatal overdose compared with other serotonergic drugs, suggesting the need for caution in patients with suicidal ideation. Because venlafaxine is a potent serotonin agonist, caution must also be exercised to prevent the possibility of serotonin syndrome when used with other serotonin agonists, and its dose should be tapered very gradually to minimize the risk of a serotonin withdrawal reaction.

CONCLUSION

Venlafaxine has emerged as a successful post-SSRI-era antidepressant with an expanded range of uses since it was first marketed.

Efficacy of venlafaxine in major depression resistant to selective serotonin reuptake inhibitors

INTRODUCTION

Some studies suggest that venlafaxine, due to its pharmacodynamic characteristics, could be an effective drug in depression, resistant to other antidepressive agents. This investigation explores the efficacy and tolerability of venlafaxine in major depression, resistant to a selective serotonin reuptake inhibitor (SSRI).

METHODS

A multicenter naturalistic study was performed during 6 months and included those patients diagnosed of major depression according to the criteria of DSM-IV who had a minimum score of 18 on the Hamilton Depression Rating Scale (HAM-D) and who had not responded to previous treatment with a SSRI at therapeutic doses for a minimum of 4 weeks. The assessment of efficacy was performed with the HAM-D scale, the Montgomery-Asberg Depression Rating Scale (MADRS), the Hamilton Anxiety Rating Scale (HAM-A) and the Global Clinical Impression (GCI). Tolerability was evaluated by recording the adverse reactions and with the GCI score on overall drug tolerability.

RESULTS

A total of 69 patients, of which 59 were evaluable for efficacy (they had fulfilled at least 4 weeks of treatment), were included. About 81% of all of them obtained a reduction of at least 50% in the HAM-D, 74% were considered as "quite improved" or "very improved" in the GCI and 69% met both criteria. The mean dose of venlafaxine used was 170.4 (S.D.=43.8) mg. Of the 21 patients who did not complete the 6 months of treatment, 3 were due to lack of efficacy, 6 due to adverse effects and 12 for other reasons. About 89.2% of side effects were considered as mild or moderate.

CONCLUSION

The results of our study support the efficacy and tolerability of venlafaxine in patients suffering from depression who have not responded to SSRI treatment.

Hippocampal volume and antidepressant response in geriatric depression

BACKGROUND

Biological markers of treatment response may include structural brain changes seen on neuroimaging. While most imaging studies have focused on cerebrovascular disease, evidence is growing that the hippocampus may play a role in depression, particularly geriatric depression.

METHOD

We studied 60 depressed elderly patients enrolled in a longitudinal study who were treated with antidepressant medications using a treatment guideline-based approach. Baseline and 12-week Montgomery-Asberg Depression Rating Scale (MADRS) scores were obtained via interview with a geriatric psychiatrist. All subjects had a baseline magnetic resonance imaging (MRI) brain scan. MRI scans were processed using standard protocols to determine total cerebral volume and right and left hippocampal volumes. Hippocampal volumes were standardized for total cerebral volume. MADRS scores less than 10 were used to define remission.

RESULTS

When the group with the lowest quartile of standardized hippocampal volumes was compared to those above the first quartile, those with small right and total hippocampal volumes were less likely to achieve remission. In a subsequent logistic regression model controlling for age small standardized right hippocampal volumes remained significantly associated with remission.

CONCLUSION

Further studies with larger sample are needed to determine if left-right hippocampal volume differences do exist in depression, and basic neuroscience studies will need to elucidate the role of the hippocampus in geriatric depression.

Proconvulsant effects of high doses of venlafaxine in pentylenetetrazole-convulsive rats

Venlafaxine, an atypical antidepressant drug, has been used to treat several neurological disorders, presenting excellent efficacy and tolerability. Clinical seizures after venlafaxine treatment have occasionally been reported when the drug was used at very high doses or in combination with other medications. The aim of the present study was to investigate the convulsant effects of venlafaxine in rats under controlled laboratory conditions. Adult male Wistar rats (8 per group) receiving venlafaxine or saline at the doses of 25-150 mg/kg were subjected 30 min later to injections of pentylenetetrazole at the dose of 60 mg/kg. The animals receiving 75, 100 and 150 mg/kg venlafaxine presented increased severity of convulsion when compared to controls (P = 0.02, P = 0.04, and P = 0.0004, respectively). Indeed, an increased percentage of death was observed in these groups (50, 38, and 88%, respectively) when compared to the percentage of death in the controls (0%). The group receiving 150 mg/kg showed an reduction in death latency (999 +/- 146 s) compared to controls (1800 +/- 0 s; cut-off time). Indeed, in this group, all animals developed seizures prior to pentylenetetrazole administration. Surprisingly, the groups receiving venlafaxine at the doses of 25 and 50 mg/kg showed a tendency towards an increase in the latency to the first convulsion. These findings suggest that venlafaxine at doses of 25 and 50 mg/kg has some tendency to an anticonvulsant effect in the rat, whereas doses of 75, 100 and 150 mg/kg presented clear proconvulsant effects in rats submitted to the pentylenetetrazole injection. These findings are the first report in the literature concerning the role of venlafaxine in seizure genesis in the rat under controlled conditions.

A current review of olanzapine's safety in the geriatric patient: from pre-clinical pharmacology to clinical data

OBJECTIVE

Olanzapine (OLZ) is unique among currently available antipsychotic medications in its antagonism of a range of receptor systems including dopamine, norepinephrine, serotonin, acetylcholine, and histamine. Olanzapine's mechanistic complexity provides a broad efficacy profile in patients with schizophrenia and acute, pure or mixed mania. Patients experience symptomatic relief of mania, anxiety, hallucinations, delusions, and agitation/aggression and reduced depressive, negative, and some cognitive symptoms. This paper will review the safety profile of OLZ, focusing on the elderly, where data are available.

METHOD

Preclinical and clinical studies of OLZ are reviewed, with emphasis on its possible effects on the cholinergic system and the histamine H(1) receptor. Weight change and related metabolic considerations, cardiac and cardiovascular safety, and motor function during treatment with OLZ are also reviewed.

RESULTS AND CONCLUSION

In vitro receptor characterization methods, when done using physiologically relevant conditions allow accurate prediction of the relatively low rate of anticholinergic-like adverse events, extrapyramidal symptoms, and cardiovascular adverse events during treatment with OLZ. Currently available clinical data suggest olanzapine is predictably safe in treating adult patients of any age with schizophrenia and acute bipolar mania, as well as in treatment of patients with some types of neurodegenerative disorders.