Efficacy and tolerability of milnacipran in the treatment of major depression in comparison with other antidepressants : a systematic review and meta-analysis

The Relationship Between 5-Hydroxytryptamine and Its Metabolite Changes With Post-stroke Depression

Post-stroke depression (PSD) is the most common and serious sequelae of stroke. Approximately 33% of stroke survivors were affected by PSD. However, many issues (e.g., incidence, diagnostic marker, and risk factor) related to PSD remained unclear. The "monoamine hypothesis" is a significant hypothesis for depression, which suggests that three monoamines play a key role in depression. Therefore, most current antidepressants are developed to modulate the monoamines on PSD treatment, and these antidepressants have good effects on patients with PSD. However, the potential mechanisms of three monoamines in PSD are still unclear. Previously, we proposed "three primary emotions," which suggested a new model of basic emotions based on the three monoamines. It may provide a new way for PSD treatment. In addition, recent studies have found that monoamine-related emotional intervention also showed potential effects in the treatment and prevention of PSD. This study discusses these issues and attempts to provide a prospect for future research on PSD.

Psychiatric comorbidities and use of milnacipran in patients with chronic dizziness

BACKGROUND

Psychiatric comorbidities are an important issue in the treatment of chronic dizziness patients.

OBJECTIVE

To test the correlation between psychiatric status and subjective handicaps and to examine the effects of milnacipran on handicaps.

METHODS

Hospital anxiety and depression scale (HADS) and handicaps were assessed by a questionnaire before and eight weeks after milnacipran treatment (50 mg/day) in 29 consecutive patients with chronic dizziness. Effects of milnaciplan were compared with fluvoxamine (200 mg/day).

RESULTS

A significant correlation was found between anxious and depressive scale scores and also between HADS and handicaps. Duration of symptoms was longer in the anxious/depressive group (HADS≧13) than in the non-anxious/depressive group. Handicaps and HADS were significantly decreased after treatment only in the anxious/depressive group. There were no overall differences in drug effects between milnaciplan and fluvoxamine. However, the rate of patients with a post/pre ratio of handicaps <80% was higher in milnaciplan group compared with the fluvoxamine group.

CONCLUSIONS

Not only anxiety disorders but also depression should be considered as comorbid psychiatric disorders in patients with chronic dizziness. Dizzy patients with psychiatric comorbidities have a longer duration of symptoms and more handicaps than those without psychiatric disorders. Milnacipran may be chosen as a treatment for patients with chronic dizziness with comorbid psychiatric disorders in case of and insufficient response to SSRIs.

Serotonin and Norepinephrine Reuptake Inhibitors

This chapter covers antidepressants that fall into the class of serotonin (5-HT) and norepinephrine (NE) reuptake inhibitors. That is, they bind to the 5-HT and NE transporters with varying levels of potency and binding affinity ratios. Unlike the selective serotonin (5-HT) reuptake inhibitors (SSRIs), most of these antidepressants have an ascending rather than a flat dose-response curve. The chapter provides a brief review of the chemistry, pharmacology, metabolism, safety and adverse effects, clinical use, and therapeutic indications of each antidepressant. Venlafaxine, a phenylethylamine, is a relatively weak 5-HT and weaker NE uptake inhibitor with a 30-fold difference in binding of the two transporters. Therefore, the drug has a clear dose progression, with low doses predominantly binding to the 5-HT transporter and more binding of the NE transporter as the dose ascends. Venlafaxine is metabolized to the active metabolite O-desmethylvenlafaxine (ODV; desvenlafaxine) by CYP2D6, and it therefore is subject to significant inter-individual variation in blood levels and response dependent on variations in CYP2D6 metabolism. The half-life of venlafaxine is short at about 5 h, with the ODV metabolite being 12 h. Both parent compound and metabolite have low protein binding and neither inhibit CYP enzymes. Therefore, both venlafaxine and desvenlafaxine are potential options if drug-drug interactions are a concern, although venlafaxine may be subject to drug-drug interactions with CYP2D6 inhibitors. At low doses, the adverse effect profile is similar to an SSRI with nausea, diarrhea, fatigue or somnolence, and sexual side effects, while venlafaxine at higher doses can produce mild increases in blood pressure, diaphoresis, tachycardia, tremors, and anxiety. A disadvantage of venlafaxine relative to the SSRIs is the potential for dose-dependent blood pressure elevation, most likely due to the NE reuptake inhibition caused by higher doses; however, this adverse effect is infrequently observed at doses below 225 mg per day. Venlafaxine also has a number of potential advantages over the SSRIs, including an ascending dose-antidepressant response curve, with possibly greater overall efficacy at higher doses. Venlafaxine is approved for MDD as well as generalized anxiety disorder, social anxiety disorder, and panic disorder. Desvenlafaxine is the primary metabolite of venlafaxine, and it is also a relatively low-potency 5-HT and NE uptake inhibitor. Like venlafaxine it has a favorable drug-drug interaction profile. It is subject to CYP3A4 metabolism, and it is therefore vulnerable to enzyme inhibition or induction. However, the primary metabolic pathway is direct conjugation. It is approved in the narrow dose range of 50-100 mg per day. Duloxetine is a more potent 5-HT and NE reuptake inhibitor with a more balanced profile of binding at about 10:1 for 5HT and NE transporter binding. It is also a moderate inhibitor of CYP2D6, so that modest dose reductions and careful monitoring will be needed when prescribing duloxetine in combination with drugs that are preferentially metabolized by CYP2D6. The most common side effects identified in clinical trials are nausea, dry mouth, dizziness, constipation, insomnia, asthenia, and hypertension, consistent with its mechanisms of action. Clinical trials to date have demonstrated rates of response and remission in patients with major depression that are comparable to other marketed antidepressants reviewed in this book. In addition to approval for MDD, duloxetine is approved for diabetic peripheral neuropathic pain, fibromyalgia, and musculoskeletal pain. Milnacipran is marketed as an antidepressant in some countries, but not in the USA. It is approved in the USA and some other countries as a treatment for fibromyalgia. It has few pharmacokinetic and pharmacodynamic interactions with other drugs. Milnacipran has a half-life of about 10 h and therefore needs to be administered twice per day. It is metabolized by CYP3A4, but the major pathway for clearance is direct conjugation and renal elimination. As with other drugs in this class, dysuria is a common, troublesome, and dose-dependent adverse effect (occurring in up to 7% of patients). High-dose milnacipran has been reported to cause blood pressure and pulse elevations. Levomilnacipran is the levorotary enantiomer of milnacipran, and it is pharmacologically very similar to the racemic compound, although the side effects may be milder within the approved dosing range. As with other NE uptake inhibitors, it may increase blood pressure and pulse, although it appears to do so less than some other medications. All medications in the class can cause serotonin syndrome when combined with MAOIs.

Efficacy and safety of multiple doses of levomilnacipran extended-release for the treatment of major depressive disorder

OBJECTIVE

The aim of this meta-analysis was to evaluate the efficacy and safety of levomilnacipran extended-release (ER) in the treatment of major depressive disorder (MDD).

METHODS

Randomized controlled trials were searched by electronic databases. Unpublished data were also searched by the relevant websites. Weighted mean difference (WMD) and risk ratio (RR) with 95% confidence interval (CI) were calculated and pooled using fixed-effects model or random-effects model.

RESULTS

Five randomized placebo-controlled trials including 2,637 patients were analyzed. Compared with placebo, levomilnacipran ER had a greater reduction in the Montgomery-Åsberg Depression Rating Scale (MADRS) total score and Sheehan Disability Scale (SDS) total score (MADRS: WMD -3.49 [95% CI -4.28, -2.70; P<0.00001]; SDS: WMD -2.41 [95% CI -3.05, -1.77; P<0.00001]). Significantly more patients in levomilnacipran ER achieved MADRS response rate (RR 1.35 [95% CI 1.23, 1.47; P<0.00001]) and MADRS remission rate (RR 1.30 [95% CI 1.06, 1.59; P=0.01]). In terms of safety, more patients discontinued due to adverse events (AEs) in levomilnacipran ER compared with placebo (RR 3.15 [95% CI 2.26, 4.39; P<0.00001]), but it was generally well tolerated in each eligible trial. The most common AEs were nausea, delay in ejaculation, erectile dysfunction, tachycardia, headache and increase in heart rate.

CONCLUSION

Levomilnacipran ER is a safe and effective short-term treatment for MDD (≤10 weeks). Long-term and head-to-head trials comparing levomilnacipran ER with other antidepressants are needed to confirm the conclusion.

Levomilnacipran (Fetzima™) for the treatment of major depressive disorder

Levomilnacipran (Fetzima™) was approved by the United States Food and Drug Administration (FDA) in July 2013 for the treatment of Major Depressive Disorder (MDD) in adults. Levomilnacipran is the (1S,2R) enantiomer of racemic milnacipran and represents one of the newest medications designed and marketed as an enantiomer of an already approved medication with hopes of improving efficacy and limiting side effects. This article reviews the evidence supporting the use of milnacipran for MDD, examines the clinical studies behind levomilnacipran's approval, and discusses practical considerations regarding the use of this new antidepressant medication.

Levomilnacipran for major depressive disorder: a systematic review of the efficacy and safety profile for this newly approved antidepressant--what is the number needed to treat, number needed to harm and likelihood to be helped or harmed?

OBJECTIVE

To describe the efficacy and safety of levomilnacipran (extended-release capsules) for the treatment of major depressive disorder (MDD).

DATA SOURCES

The pivotal registration trials were accessed by querying http://www.ncbi.nlm.nih.gov/pubmed/, http://www.clinicaltrialsregister.eu and http://www.clinicaltrials.gov for the search terms 'levomilnacipran' and 'F2695', and by obtaining posters presented at congresses. Product labelling provided additional information.

STUDY SELECTION

All available clinical reports of studies were identified.

DATA EXTRACTION

Descriptions of the principal results and calculation of number needed to treat (NNT) and number needed to harm (NNH) for relevant dichotomous outcomes were extracted from the available study reports and other sources of information.

DATA SYNTHESIS

Levomilnacipran (1S, 2R-milnacipran) is a potent and selective serotonin-norepinephrine reuptake inhibitor with greater potency for inhibition of norepinephrine relative to serotonin reuptake. Approval for the treatment of MDD was based on a clinical development program that included one 10-week Phase II and four 8-week Phase III randomised placebo-controlled clinical trials in outpatients with MDD where levomilnacipran was titrated to target doses ranging from 40 to 120 mg taken once daily. Four of the five trials demonstrated efficacy as measured by the Montgomery Asberg Depression Rating Scale, with a NNT for response vs. placebo of 9 (95% CI 7-15), and for remission, 14 (95% CI 10-28). Levomilnacipran also demonstrated superiority over placebo as measured by improvement in the Sheehan Disability Scale functional impairment total score. NNH vs. placebo for discontinuation because an adverse event (AE) across all five trials was 19 (95% CI 14-28). The most commonly encountered AEs (incidence ≥ 5% and at least twice the rate of placebo) as identified in product labelling were nausea, hyperhidrosis, constipation, heart rate increased, erectile dysfunction in men, vomiting, tachycardia and palpitations, with NNH values vs. placebo of 10 (95% CI 8-12), 15 (95% CI 12-19), 17 (95% CI 13-24), 21 (95% CI 17-29), 20 (95% CI 14-36), 25 (95% CI 20-37), 25 (95% CI 19-40) and 30 (95% CI 22-49), respectively. Levomilnacipran was not associated with clinically relevant weight change in the short-term trials or in a 48-week open-label extension trial. Mean changes from baseline in systolic blood pressure (BP), diastolic BP and heart rate were +3.0 mmHg, +3.2 mm Hg and +7.4 bpm for levomilnacipran, and -0.4 mmHg, no change and -0.3 bpm for placebo, respectively. Categorical shift in BP from normal or prehypertension at baseline to stage 1 or stage 2 hypertension at end of study was 10.4% for levomilnacipran vs. 7.1% for placebo, for a NNH of 31 (95% CI 18-94).

CONCLUSIONS

Levomilnacipran represents another option for the treatment of MDD. Levomilnacipran appears to have a favourable weight-gain profile. Additional controlled data regarding long-term efficacy and comparative effectiveness will help characterise this new agent.

Polypharmacy or medication washout: an old tool revisited

There has been a rapid increase in the use of polypharmacy in psychiatry possibly due to the introduction of newer drugs, greater availability of these newer drugs, excessive confidence in clinical trial results, widespread prescribing of psychotropic medications by primary care, and pressure to augment with additional medications for unresolved side effects or greater efficacy. Even the new generation of medications may not hold significant advantages over older drugs. In fact, there may be additional safety risks with polypharmacy being so widespread. Washout, as a clinical tool, is rarely done in medication management today. Studies have shown that augmenting therapy with additional medications resulted in 9.1%-34.1% dropouts due to intolerance of the augmentation, whereas studies of medication washout demonstrated only 5.9%-7.8% intolerance to the washout procedure. These perils justify reconsideration of medication washout before deciding on augmentation. There are unwarranted fears and resistance in the medical community toward medication washout, especially at the moment a physician is trying to decide whether to washout or add more medications to the treatment regimen. However, medication washout provides unique benefits to the physician: it establishes a new baseline of the disorder, helps identify medication efficacy from their adverse effects, and provides clarity of diagnosis and potential reduction of drug treatments, drug interactions, and costs. It may also reduce overall adverse events, not to mention a potential to reduce liability. After washout, physicians may be able to select the appropriate polypharmacy more effectively and safely, if necessary. Washout, while not for every patient, may be an effective tool for physicians who need to decide on whether to add potentially risky polypharmacy for a given patient. The risks of washout may, in some cases, be lower and the benefits may be clearly helpful for diagnosis, understanding medication effects, the doctor/patient relationship, and safer use of polypharmacy if indicated.

Therapeutic armamentarium for treating depression

Depressive disorders are highly prevalent and are a leading cause of disability, morbidity, and mortality worldwide; however, they often remain undertreated or untreated. This article provides a broad overview of the many strategies for treating depression. More than 24 antidepressant medications and depression-focused psychotherapies are available as first-choice options for treating depression. When patients have not had a satisfactory treatment response, the 2 main strategies are switching to an alternative antidepressant therapy or adding a second antidepressant therapy. A large number of medication combinations have been reported in the literature, and some have been shown to be effective in controlled studies. Nonstandard alternatives to conventional antidepressant treatments include exercise, light therapy, sleep deprivation, and various complementary and alternative therapies. For more chronic and refractory forms of depression, various neuromodulation therapies are available or are being investigated. Because depressive disorders are common in primary care and other medical settings, medical practitioners should be aware of the therapeutic armamentarium available for treating depression.

Getting the balance right: Established and emerging therapies for major depressive disorders

Major depressive disorder (MDD) is a common and serious illness of our times, associated with monoamine deficiency in the brain. Moreover, increased levels of cortisol, possibly caused by stress, may be related to depression. In the treatment of MDD, the use of older antidepressants such as monoamine oxidase inhibitors and tricyclic antidepressants is decreasing rapidly, mainly due to their adverse effect profiles. In contrast, the use of serotonin reuptake inhibitors and newer antidepressants, which have dual modes of action such as inhibition of the serotonin and noradrenaline or dopamine reuptake, is increasing. Novel antidepressants have additive modes of action such as agomelatine, a potent agonist of melatonin receptors. Drugs in development for treatment of MDD include triple reuptake inhibitors, dual-acting serotonin reuptake inhibitors and histamine antagonists, and many more. Newer antidepressants have similar efficacy and in general good tolerability profiles. Nevertheless, compliance with treatment for MDD is poor and may contribute to treatment failure. Despite the broad spectrum of available antidepressants, there are still at least 30% of depressive patients who do not benefit from treatment. Therefore, new approaches in drug development are necessary and, according to current research developments, the future of antidepressant treatment may be promising.

Milnacipran: beyond a role of antidepressant

Milnacipran is a serotonin and norepinephrine reuptake inhibitor (SNRI) with negligible effects on any presynaptic or postsynaptic receptors. Milnacipran has unique pharmacokinetic and pharmacodynamic characteristics that distinguish it from the other marketed serotonin and norepinephrine reuptake inhibitors, venlafaxine, desvenlafaxine, and duloxetine such as equipotent serotonin and norepinephrine reuptake inhibition and a linear dose-concentration trend at therapeutic doses. The half-life of milnacipran is approximately 8 hours. In addition, milnacipran does not inhibit the cytochrome P 450 system, indicating minimal propensity for drug-drug interactions. The antidepressant efficacy of milnacipran has been clearly established in a number of randomized, double-blind, placebo-controlled clinical trials, and it has been widely used for treating major depressive disorder. Moreover, evidence suggests that milnacipran is effective and tolerable in the treatment of fibromyalgia and may have usefulness for fatigue and anxiety symptoms. The current paper reviews researches conducted to date that is relevant to the efficacy, tolerability, and mechanism of action of milnacipran in the treatment of depression, fibromyalgia, and other psychiatric syndromes. Future directions of research are also identified.

Serotonin norepinephrine reuptake inhibitors (SNRIs) in anxiety disorders: a comprehensive review of their clinical efficacy

Anxiety disorders are common psychiatric conditions that typically require long-term treatment. This review summarizes current knowledge of the pharmacological treatment of anxiety disorders with serotonin norepinephrine reuptake inhibitors (SNRIs) with specific emphasis on the findings of recent randomized clinical trials and relevant neurobiological investigations. It is now well established that gabaergic, noradrenergic and serotonergic systems play a critical role in the pathophysiology of anxiety disorders, abnormalities in these systems being related to structural and functional alterations in specific brain areas such as the amygdala, prefrontal cortex, locus coeruleus and hippocampus, as repeatedly shown by neuroimaging studies. SNRIs selectively inhibit norepinephrine and serotonin reuptake and have shown to be efficacious and generally well tolerated treatments in patients with anxiety disorders, with some potential clinical advantages over selective serotonin reuptake inhibitors (SSRIs), which are considered by many to represent first-line pharmacological treatments in patients with anxiety disorders. Anxiety disorders are characterized by a typically chronic course, high rates of comorbidity and frequent partial response to standard treatments, and the increasing use of SNRIs reflects currently unmet clinical need, in terms of overall response, remission rates and treatment tolerability.

Pharmacological and combined interventions for the acute depressive episode: focus on efficacy and tolerability

BACKGROUND

Use of antidepressants is the gold standard therapy for major depression. However, despite the large number of commercially available antidepressant drugs there are several differences among them in efficacy, tolerability, and cost-effectiveness. In addition the optimal augmentation strategy is still not clear when dealing with treatment-resistant depression, a condition that affects 15% to 40% of depressed patients.

METHODS

We therefore reviewed the main characteristics of these drugs regarding their efficacy, tolerability, side effects and cost-effectiveness, by accessing all meta-analyses and systematic reviews published from 2004 to 2009. In addition, we reviewed the augmentation strategy of associated antidepressants with neurostimulation therapies (such as transcranial magnetic stimulation [TMS] and transcranial direct current stimulation [tDCS]). A search was undertaken in MEDLINE, Web of Science, Cochrane, and Scielo databases. We included: 21 meta-analyses of antidepressant trials, 15 neurostimulation clinical trials and 8 studies of pharmacoeconomics. We then performed a comprehensive review on these articles.

RESULTS AND CONCLUSION

Although recent meta-analyses suggest sertraline and escitalopram might have increased efficacy/tolerability, other studies and large pragmatic trials have not found these to be superior to other antidepressant drugs. Also, we did not identify any superior drug in terms of cost-effectiveness due to the different designs observed among pharmacoecomics studies. Side effects such as sexual dysfunction, gastrointestinal problems and weight gain were common causes of discontinuation. Tolerability was an important issue for novel neurostimulation interventions, such as TMS and tDCS. These therapies might be interesting augmentation strategies, considering their benign profile of side effects, if proper safety parameters are adopted.

1- or 3-(3-Amino-2-hydroxy-1-phenyl propyl)-1,3-dihydro-2H-benzimidazol-2-ones: potent, selective, and orally efficacious norepinephrine reuptake inhibitors

Sequential structural modifications of the aryloxypropanamine template (e.g., atomoxetine, 2) led to a novel series of 1-(3-amino-2-hydroxy-1-phenyl propyl)-1,3-dihydro-2H-benzimidazol-2-ones as selective norepinephrine reuptake inhibitors (NRIs). In general, this series of compounds potently blocked the human norepinephrine transporter (hNET) while exhibiting selectivity at hNET against both the human serotonin (hSERT) and dopamine transporters (hDAT). Numerous compounds (e.g., 19-22) had low nonamolar hNET potency with IC(50) values of 7-10 nM and excellent selectivity (>500 fold) at hNET over hSERT and hDAT. Several compounds, such as 20 and 22, were tested in a telemetric rat model of ovariectomized-induced thermoregulatory dysfunction and were efficacious at oral doses of 3 mg/kg in reducing the tail skin temperature. In addition, compound 20 was also studied in the rat hot plate and spinal nerve ligation (SNL) models of acute and neuropathic pain, respectively, and was orally efficacious at doses of 3-10 mg/kg.

Milnacipran

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