Selegiline transdermal system in the prevention of relapse of major depressive disorder: a 52-week, double-blind, placebo-substitution, parallel-group clinical trial

Translation from Preclinical Research to Clinical Trials: Transdermal Drug Delivery for Neurodegenerative and Mental Disorders

Neurodegenerative diseases (NDs), particularly dementia, provide significant problems to worldwide healthcare systems. The development of therapeutic materials for various diseases has a severe challenge in the form of the blood-brain barrier (BBB). Transdermal treatment has recently garnered widespread favor as an alternative method of delivering active chemicals to the brain. This approach has several advantages, including low invasiveness, self-administration, avoidance of first-pass metabolism, preservation of steady plasma concentrations, regulated release, safety, efficacy, and better patient compliance. Topics include the transdermal method for therapeutic NDs, their classification, and the mechanisms that allow the medicine to enter the bloodstream through the skin. The paper also discusses the obstacles and potential outcomes of transdermal therapy, emphasizing the benefits and drawbacks of different approaches.

Efficacy and safety of selegiline across different psychiatric disorders: A systematic review and meta-analysis of oral and transdermal formulations

Selegiline is an irreversible, selective type-B monoamine oxidase inhibitor (MAOI) approved for Parkison's disease-oral and major depressive disorder-transdermal formulation) resulting in non-selective MAOI activity at oral doses≥20 mg/day. The present systematic review and meta-analysis appraises the evidence of different formulations/dosages of selegiline across different psychiatric conditions. We inquired PubMed/MEDLINE/Cochrane-Central/WHO-ICTRP/Clarivate-WebOfScience and the Chinese-Electronic-Journal Database from inception to 10/26/2022 for selegiline trials involving psychiatric patients. Random-effects meta-analyses assessed heterogeneity, publication/risk biases, and confidence in the evidence, followed by sensitivity, subgroup, and meta-regression analyses. Co-primary outcomes were: changes in symptom score (standardized mean difference=SMD) and author-defined response (risk ratios=RRs). RRs of adverse events and all-cause discontinuation were secondary and acceptability outcomes, respectively. Systematic-review included 42 studies; meta-analysis, 23. Selegiline outperformed placebo in depressive symptom reduction (SMD=-0.96, 95%C.I.=-1.78, -0.14, k = 10, n = 1,308), depression (RR=1.61, 95%C.I.=1.20, 2.15, k = 9, n = 1,238) and atypical-depression response (RR=2.23, 95%C.I.=1.35, 3.68, k = 3, n = 136). Selegiline failed to outperform the placebo in negative (k = 4) or positive symptoms of schizophrenia (k = 4), attention-deficit-hyperactivity disorder (ADHD) symptoms reduction (k = 2), and smoking abstinence rate (k = 4). Selegiline did not differ from methylphenidate and ADHD scores (k = 2). No significant difference emerged in acceptability, incident diarrhea, headache, dizziness, and nausea RRs, in contrast to xerostomia (RR=1.58, 95%C.I. =1.03, 2.43, k = 6, n = 1,134), insomnia (RR=1.61, 95%C.I.=1.19, 2.17, k = 10, n = 1,768), and application-site reaction for transdermal formulation (RR=1.81, 95%C.I.=1.40, 2.33, k = 6, n = 1,662). Confidence in findings was low/very-low for most outcomes; moderate for depressive symptoms reduction (transdermal). Selegiline proved effective, safe, and well-tolerated for depressive disorders, yet further evidence is warranted about specific psychiatric disorders.

Effects of antidepressant medicines on preventing relapse of unipolar depression: a pooled analysis of parametric survival curves

BACKGROUND

Major depressive disorder is characterized by a high risk of relapse. We aimed to compare the prophylactic effects of different antidepressant medicines (ADMs).

METHODS

PubMed, Cochrane Central Register of Controlled Trials, Embase and the Web of Science were searched on 4 July 2019. A pooled analysis of parametric survival curves was performed using a Bayesian framework. The main outcomes were hazard ratios (HRs), relapse-free survival and mean relapse-free months.

RESULTS

Forty randomized controlled trials were included. The 1-year relapse-free survival for ADM (76%) was significantly better than that for placebo (56%). Most of the relapse difference (86.5%) occurred in the first 6 months. Most HRs were not constant over time. Proof of benefit after 6 months of follow-up was not established partially because of small differences between the drug and placebo after 6 months. Almost all studies used an 'enriched' randomized discontinuation design, which may explain the high relapse rates in the first 6 months after randomization.

CONCLUSIONS

The superiority of ADM v. placebo was mainly attributed to the difference in relapse rates that occurred in the first 6 months. Our analysis provided evidence that the prophylactic efficacy was not constant over time. A beneficial effect was observed, but the prevention of new episodes after 6 months was questionable. These findings may have implications for clinical practice.

Monoamine Oxidase Inhibitors (MAOIs) in Psychiatric Practice: How to Use them Safely and Effectively

Monoamine oxidase inhibitors (MAOIs) were among the first licensed pharmacological treatments for patients with depression but over time have fallen out of mainstream clinical use. This has led to a loss of clinician training opportunities and reduced availability of MAOIs for prescribing. This article provides a concise and practical overview of how to use MAOIs safely and effectively in psychiatric practice. We consider the history of MAOIs, why they are not used more frequently, their mechanisms of action, availability, indications and efficacy, general tolerability, withdrawal symptoms, and safety considerations (including hypertensive reactions and serotonin syndrome). Practical advice is given in terms of dietary restrictions, interactions with other medications (both prescribed and non-prescribed), and how prescribers can stop and switch MAOIs, both within the drug class and outside of it. We also provide advice on choice of MAOI and treatment sequencing. Lastly, we consider emerging directions and potential additional indications.

Blocking Astrocytic GABA Restores Synaptic Plasticity in Prefrontal Cortex of Rat Model of Depression

A decrease in synaptic plasticity and/or a change in excitation/inhibition balance have been suggested as mechanisms underlying major depression disorder. However, given the crucial role of astrocytes in balancing synaptic function, particular attention should be given to the contribution of astrocytes in these mechanisms, especially since previous findings show that astrocytes are affected and exhibit reactive-like features in depression. Moreover, it has been shown that reactive astrocytes increase the synthesis and release of GABA, contributing significantly to tonic GABA inhibition. In this study we found decreased plasticity and increased tonic GABA inhibition in the prelimbic area in acute slices from the medial prefrontal cortex in the Flinders Sensitive Line (FSL) rat model of depression. The tonic inhibition can be reduced by either blocking astrocytic intracellular Ca²⁺ signaling or by reducing astrocytic GABA through inhibition of the synthesizing enzyme MAO-B with Selegiline. Blocking GABA synthesis also restores the impaired synaptic plasticity in the FSL prefrontal cortex, providing a new antidepressant mechanism of Selegiline.

Synthetic enhancer compounds, besides acting on biogenic amine system, influence the glutamate transmission and stress response

Pharmaceutically available enhancer selegiline/(-)-deprenyl (DEP) in the clinically used dose shows antidepressant effect, but nothing is known about this effect in enhancer dose, and its effect on co-morbid anxiety. Moreover, data about the antidepressant/antianxiety effects of the serotonin-influencing enhancer, (2R)-1-(1-benzofuran-2-yl)-N-propylpentane-2-amine (BPAP) are also missing. The aim of the present paper is to establish the role of enhancer regulation in anxiety and follow the changes in the phosphorylation of glutamate subunits in prefrontal cortex as well as stress-related organ and hormonal changes as possible background mechanism. The effect of 3-week-treatment of rats with specific (0.001 mg/kg for DEP, 0.0001 mg/kg for BPAP) and non-specific (0.1 mg/kg for DEP, 0.05 mg/kg for BPAP) enhancer doses were evaluated on anxiety-like behavior in the elevated plus maze (EPM) and open-field (OF) tests. Phosphorylated glutamatergic GluR1 and GluN2B subunits were analyzed by Western blot. Changes in the stress-regulatory system were evaluated by measuring the organ weights and blood corticosterone concentrations. Non-specific enhancer doses had a tendency for anxiolysis on EPM, while only 0.1 mg/kg DEP elevated motility in OF. Specific enhancer doses significantly increased the expression of both glutamatergic receptor subunits; non-specific doses elevated only pGluR1. Treatments had no effects on stress-like organ weights; however, the specific enhancer doses significantly reduced the dark phase resting corticosterone levels. The study proved the enhancer-sensitivity of the glutamatergic transmitter system and suggested enhancer-induced stabilization of stress-hormone levels without major impact on non-stimulated anxiety-like behavior.

Selegiline: a molecule with innovative potential

Monoamine oxidase B (MAO-B) inhibitors have an established role in the treatment of Parkinson's disease as monotherapy or adjuvant to levodopa. Two major recognitions were required for their introduction into this therapeutic field. The first was the elucidation of the novel pharmacological properties of selegiline as a selective MAO-B inhibitor by Knoll and Magyar and the original idea of Riederer and Youdim, supported by Birkmayer, to explore its effect in parkinsonian patients with on-off phases. In the 1960s, MAO inhibitors were mainly studied as potential antidepressants, but Birkmayer found that combined use of levodopa and various MAO inhibitors improved akinesia in Parkinson's disease. However, the serious side effects of the first non-selective MAO inhibitors prevented their further use. Later studies demonstrated that MAO-B, mainly located in glial cells, is important for dopamine metabolism in the brain. Recently, cell and molecular studies revealed interesting properties of selegiline opening new possibilities for neuroprotective mechanisms and a disease-modifying effect of MAO-B inhibitors.

[Other therapeutic strategies]

Non-selective and irreversible MAOI have become as third or fourth-line strategy for the management of treatment-resistant depression. Non-selective and irreversible MAOI requires careful monitoring of drug interactions and dietary restrictions. Nutritional supplements such as omega-3 have been found to produce beneficial effects in the management of treatment-resistant depression when administered in combination with the ongoing antidepressant treatment. The glutamate antagonist ketamine has been found to produce beneficial effects in the management of treatment-resistant depression while administered alone. Dopamine and/or norepinephrine agonists, such as methylphenidate, modafinil or pramipexole, have been found to produce beneficial effects in the management of treatment-resistant depression when administered in combination with the ongoing antidepressant treatment.

Prevention of Relapse and Recurrence in Adults with Major Depressive Disorder: Systematic Review and Meta-Analyses of Controlled Trials

BACKGROUND

Findings of substantial remaining morbidity in treated major depressive disorder (MDD) led us to review controlled trials of treatments aimed at preventing early relapses or later recurrences in adults diagnosed with MDD to summarize available data and to guide further research.

METHODS

Reports (n = 97) were identified through systematic, computerized literature searching up to February 2015. Treatment versus control outcomes were summarized by random-effects meta-analyses.

RESULTS

In 45 reports of 72 trials (n = 14 450 subjects) lasting 33.4 weeks, antidepressants were more effective than placebos in preventing relapses (response rates [RR] = 1.90, confidence interval [CI]: 1.73-2.08; NNT = 4.4; p < 0.0001). In 35 reports of 37 trials (n = 7253) lasting 27.0 months, antidepressants were effective in preventing recurrences (RR = 2.03, CI 1.80-2.28; NNT = 3.8; p < 0.0001), with minor differences among drug types. In 17 reports of 22 trials (n = 1 969) lasting 23.7 months, psychosocial interventions yielded inconsistent or inconclusive results.

CONCLUSIONS

Despite evidence of the efficacy of drug treatment compared to placebos or other controls, the findings further underscore the substantial, unresolved morbidity in treated MDD patients and strongly encourage further evaluations of specific, improved individual and combination therapies (pharmacological and psychological) conducted over longer times, as well as identifying clinical predictors of positive or unfavorable responses and of intolerability of long-term treatments in MDD.

Efficacy and safety of selegiline transdermal system (STS) for the atypical subtype of major depressive disorder: pooled analysis of 5 short-term, placebo-controlled trials

OBJECTIVE

The objective of the present study is to investigate the efficacy and safety of the selegiline transdermal system (STS) in major depressive disorder (MDD) with atypical features.

METHODS

This was a post-hoc analysis of 5 short-term trials. The atypical subtype was defined as the presence of at least 1 item with a score of 2 or greater from items 22-26 on the 28-item Hamilton Depression Rating Scale (HAMD-28), and a maximum score of 1 point for items 6 (insomnia late), 12 (somatic symptoms, gastrointestinal), and 16 (loss of weight) to exclude vegetative features of melancholic depression. The mean changes of HAMD-28 total score from baseline to the endpoint (response rate defined as ≥50% reduction in HAMD-28 scores and remission rate defined as ≤10 HAMD-28 total score at the treatment endpoint) were compared between atypical and nonatypical groups.

RESULTS

In this analysis, 352 subjects (STS = 168 vs placebo = 184) met the definition of atypical subtype at baseline. STS (n = 641) significantly decreased HAMD-28 total score compared with placebo (n = 648) from beginning to end of treatment (-10.7 ± 9.3 vs -9.4 ± 9.3; p = 0.014). STS showed comparable efficacy in patients with the atypical subtype compared with the nonatypical subtype for placebo-subtracted mean change in HAMD-28 total score (-2.11 ± 1.01 vs. -1.0 ± 0.60; p = 0.34), odds ratio (OR) for response (1.41 vs 1.23, p = 0.62), and OR for remission (1.77 vs 1.18, p = 0.22).

CONCLUSION

STS appears to be comparably efficacious and tolerable in atypical and nonatypical subtypes of MDD. Adequately powered, controlled, clinical trials are necessary to confirm our findings.

A double-blind, placebo-controlled study of selegiline transdermal system in depressed adolescents

OBJECTIVE

A randomized, double-blind, placebo-controlled flexible-dose, parallel group trial was conducted at 26 clinical investigational sites in the United States to examine the safety and efficacy of the selegiline transdermal system (STS) (EMSAM®) in adolescents (ages 12-17 years) meeting American Psychiatric Association, Diagnostic and Statistical Manual of Mental Disorders, 4th ed. (DSM-IV) criteria for moderate to severe major depressive disorder (MDD) without psychotic features.

METHODS

Adolescents (n=308) with moderate to severe MDD were randomized to either STS (n=152) or placebo (n=156). Two hundred and fifteen (69.8%) subjects completed the study and 17 (5.5%) reported discontinuation because of adverse events (AEs). The primary efficacy outcome measure was the mean change from baseline to end of study (week 12 last observation carried forward [LOCF]) in the Children's Depression Rating Scale-Revised (CDRS-R) total score. Secondary outcome measures included end-point Clinical Global Impressions - Severity (CGI-S) and Clinical Global Impressions - Improvement (CGI-I).

RESULTS

Patients on STS or placebo had a significant decline from baseline (p<0.001) on their CDRS-R total score with mean reductions±SD as follows: STS 21.4±16.6; placebo 21.5±16.5. Both groups had similar response rates (58.6% vs. 59.3%) defined as CGI-I of 1 or 2 at study end. However, these between-group efficacy findings were without statistical significance. The overall incidence of reported AEs was 62.5% for STS-treated patients and 57.7% for placebo-treated patients. Most commonly reported AEs in STS or placebo groups were application site reactions (STS=24.3%; placebo=21.8%), headache (STS=17.1%; placebo=16.7%), and nausea (STS=7.2%; placebo=7.7%). Treatment groups did not differ on any laboratory parameters, vital signs, or electrocardiogram (ECG) findings. No suspected hypertensive crises were reported in the trial.

CONCLUSIONS

These data demonstrated that the STS was safe and well tolerated in this adolescent sample. However, both STS-treated and placebo-treated subjects demonstrated a decline from baseline in depressive symptoms (CDRS-R total score) over the length of the study, without statistical superiority by either group.

Effects of combined MAO-B inhibitors and levodopa vs. monotherapy in Parkinson's disease

Background: Prior studies report that monoamine oxidases inhibitors (MAO-I) when used as an adjunct to levodopa ameliorate motor symptoms in Parkinson’s disease (PD), but this was not tested in relation to cognitive or psychiatric measures.

Objective: Here, we tested the effects of MAO-I as an adjunct to levodopa, in comparison to levodopa or dopamine (DA) agonists alone, on various cognitive, affective and quality of life measures.

Methods: We studied three groups of subjects: healthy controls, PD patients on combined levodopa and MAO-I, and PD patients on levodopa or DA agonists only.

Results: We found that compared to monotherapy, combined MAO-I and levodopa seemed to improve cognition, including probabilistic learning, working memory and executive functions. There were no differences between the different medication regimes on deterministic learning, attention or memory recall. It was also found that MAO-I as an adjunct to levodopa improves affective measures such as depression, apathy, anxiety and quality of life. Interestingly, this enhancing effect of combined levodopa and MAO-I was more pronounced in PD patients with severe akinesia, compared to patients with severe tremor.

Conclusion: Our data are in agreement with (a) the Continuous Dopaminergic Stimulation (CDS) theory which states that continuous stimulation of the basal ganglia enhances motor, psychiatric and cognitive functions in PD patients; and/or (b) findings that MAO-I increase the bioavailability of monoamines that have beneficial effects on motor and behavioral dysfunction in PD.

EMSAM (deprenyl patch): how a promising antidepressant was underutilized

The EMSAM patch is a unique monoamine oxidase inhibitor (MAOI) being the only antidepressant utilizing a transdermal delivery system. This was welcomed by clinicians who hoped that EMSAM would be better tolerated than oral MAOIs and non-MAOI antidepressants, as well as being effective for treatment in a wide spectrum of depressed patients including atypical depression, bipolar depression, and refractory depression. Unfortunately, the clinical use of EMSAM has been underutilized and its potential usefulness overlooked. This article suggests that fear of possible side effects, particularly the "cheese reaction" and serotonin syndrome, are some of the main contributors to underutilization by clinicians. These risks have been significantly exaggerated with the 6 mg/day dose not even requiring a special diet. Other contributing factors leading to underutilization are reviewed such as: the lack of studies addressing many important clinical questions; inadequate data analyses; not evaluating the effect of EMSAM on comorbid psychiatric conditions, particularly anxiety disorders; lack of antidepressant comparators versus EMSAM; no dose-response relationship examined; various depressive subtypes and conditions are unexplored, eg, bipolar depression and refractory depression; poor insurance coverage for an expensive medication; as well as minimal marketing efforts and postmarketing studies. On the other hand, many potential advantages of EMSAM are not highlighted enough in the literature and by pharmaceutical companies which might have increased clinical interest and utilization of the antidepressant. For example, the advantages of EMSAM include: avoidance of swallowing issues, as can be seen with oral antidepressants; minimal side effects, probably due to a favorable pharmacokinetic profile; minimal evidence of suicidal behavior, probably relating to the transdermal route of administration; low rates of inducing hypomanic/manic episodes; as well as significant efficacy in "anxious depression" and atypical depression. Recent efforts in conducting some post hoc analyses and presentations on EMSAM may yet stimulate further clinical interest and use of this antidepressant.

Predictors of relapse in patients with major depressive disorder in a 52-week, fixed dose, double blind, randomized trial of selegiline transdermal system (STS)

OBJECTIVE

We investigated patient and disease characteristics predictive of relapse of MDD during a 52-week placebo controlled trial of selegiline transdermal system (STS) to identify patient characteristics relevant for STS treatment.

METHOD

After 10 weeks of open-label stabilization with STS, 322 remitted patients with MDD were randomized to 52-weeks of double-blind treatment with STS (6 mg/24h) or placebo (PLB). Relapse was defined as Hamilton Depression Rating Scale (HAMD-17) score of ≥ 14 and a CGI-S score of ≥ 3 with at least 2-point increase from the beginning of the double blind phase on 2 consecutive visits. Cox's proportional hazards regression was used to examine the effect of potential predictors (age, sex, age at onset of first MDD, early response pattern, number of previous antidepressant trials, severity of index episode, number of previous episodes, melancholic features, atypical features and anxious feature) on outcome. Exploratory analyses examined additional clinical variables (medical history, other psychiatric history, and individual items of HAM-D 28) on relapse.

RESULTS

For all predictor variables analyzed, treatment Hazard Ratio (HR=0.48~0.54) was significantly in favor of STS (i.e., lower relapse risk than PLB). Age of onset was significantly predictive of relapse. Type, duration, and severity of depressive episodes, previous antidepressant trials, or demographic variables did not predict relapse. In additional exploratory analysis, eating disorder history and suicidal ideation were significant predictors of relapse after controlling for the effect of treatment in individual predictor analysis.

CONCLUSIONS

While age of onset, eating disorder history and suicidal ideation were significant predictors, the majority of clinical and demographic variables were not predictive of relapse. Given the post-hoc nature of analysis, the findings need confirmation from a prospective study. It appears that selegiline transdermal system was broadly effective in preventing relapse across different subtypes and symptoms clusters of MDD.

Placing transdermal selegiline for major depressive disorder into clinical context: number needed to treat, number needed to harm, and likelihood to be helped or harmed

BACKGROUND

This is a quantitative review of existing studies of transdermal selegiline for major depressive disorder.

METHODS

Data for dichotomous outcomes were extracted from the five 6-8 week studies of transdermal selegiline. Number needed to treat (NNT) vs. placebo was calculated for response and remission using standard definitions. Number needed to harm (NNH) vs. placebo for commonly encountered adverse events (AEs), AEs associated with sexual function, incidence of weight gain ≥5% from baseline, and discontinuation due to an AE, were also calculated. Data was pooled as appropriate and likelihood to be helped or harmed (LHH) ratios contrasting remission with selected tolerability outcomes were determined.

RESULTS

When pooling together the two pivotal trials as identified in product labeling, NNT for response was 11 (95% CI 6-109) and for remission, 9 (95% CI 6-28). Pooling all trials, NNH for application site reaction was 7 (95% CI 6-10) and for insomnia, 19 (95% CI 12-41). There were no clinically relevant differences from placebo regarding weight gain or impairment in sexual functioning. NNH for discontinuation due to an AE was 32 (95% CI 19-132). LHH for remission vs. discontinuation from treatment due to an AE was 3.6.

LIMITATIONS

The studies included were not identical in design. The studies were registrational in nature and thus not necessarily generalizable.

CONCLUSIONS

NNT for transdermal selegiline for efficacy is similar to that for other antidepressant regimens for which similar analyses have been published. There appear to be no clinically relevant effects of selegiline on weight or sexual functioning.

Reducing the Burden of Difficult-to-Treat Major Depressive Disorder: Revisiting Monoamine Oxidase Inhibitor Therapy

OBJECTIVE

Difficult-to-treat depression (eg, depression with atypical or anxious symptoms, treatment-resistant depression, or depression with frequent recurrence) is a challenging real-world health issue. This critical review of the literature focuses on monoamine oxidase inhibitor (MAOI) therapy and difficult-to-treat forms of depression.

DATA SOURCES

A literature search was performed in November 2012 and refreshed through January 2013 with no date restrictions using key search terms including MAO inhibitor therapy or MAOI and depression and anxiety, atypical, treatment-resistant, recurrent, relapse, or refractory.

STUDY SELECTION

Articles were selected to summarize the current needs in difficult-to-treat depression as well as the use of MAOI therapies in this area.

RESULTS

Two strategies have fallen out of favor in the care of patients with major depressive disorder. The first is the use of MAOI therapy and the second is the proactive recognition of difficult-to-treat depression that may not respond as well to more frequently used antidepressants. The infrequent use of MAOIs stems from the perception that other oral therapies for depression are safer and easier to use than oral MAOIs; however, transdermal delivery is one potential strategy to improve the safety of this class of agents. Although food-related interactions with transdermal delivery of MAOI therapy can be lessened, clinicians still need to be vigilant for drug-drug interactions and serotonin syndrome.

CONCLUSIONS

Clinicians should consider MAOIs for patients who have had several unsuccessful trials of antidepressants. Guidelines generally reserve MAOIs as third- and fourth-line treatments due to concerns over safety and tolerability; however, transdermal delivery of an MAOI may allay some of the safety and tolerability concerns. Patients should be provided education about MAOIs and their risks.

Current place of monoamine oxidase inhibitors in the treatment of depression

This paper reviews the discovery and history of the use of irreversible monoamine oxidase (MAO) inhibitors (MAOIs) such as phenelzine, tranylcypromine and isocarboxazid, as well as the second generation selective and reversible MAOIs such as the MAO-A inhibitor, moclobemide and the MAO-B inhibitor, selegiline. Data for review were identified from a literature search of OvidSP Medline and PsycInfo performed in July 2012, using the subject terms and keywords of 'monoamine oxidase inhibitors', 'major depression', 'depressive disorder' and 'depression (emotion)'. The search was limited to papers published in the English language and from 2007 onward only. Irreversible MAOIs have the potential to treat the most challenging mood disorder patients including those with treatment-resistant depression, atypical depression and bipolar depression. Unfortunately, the use of irreversible MAOIs has been declining sharply due to lack of marketing and the excessive fears of clinicians. Moreover, few clinicians now have any experience, let alone comfort, in prescribing this class of antidepressants. The newer MAOIs are available as another option for the treatment of major depression but have not replaced the irreversible MAOIs for the specific sub-types of depression for which they are now recommended in most consensus guidelines and treatment algorithms. The pharmacology, drug interactions and dietary recommendations associated with the use of MAOIs are reviewed. With the appropriate dietary restrictions and attention to potential drug interactions with serotonin and noradrenaline agents this class of drugs can be used effectively and safely. The MAOIs still represent an important element in our therapeutic armamentarium. Despite recommendations by opinion leaders and consensus guidelines for the use of MAOIs in specific sub-types of depression, the prescription rate of MAOIs is far less than expected and is decreasing. The "bad reputation" and the lack of industry support for this class of agents (especially the irreversible MAOIs) must be overcome in order to continue to provide a potentially useful treatment for a very vulnerable yet substantial sub-population of mood disorder patients.

Diagnosis and treatment of depression in patients with congestive heart failure: a review of the literature

CONTEXT

Major depressive disorder (MDD) can be challenging to diagnose in patients with congestive heart failure, who often suffer from fatigue, insomnia, weight changes, and other neurovegetative symptoms that overlap with those of depression. Pathophysiologic mechanisms (eg, inflammation, autonomic nervous system dysfunction, cardiac arrhythmias, and altered platelet function) connect depression and congestive heart failure.

OBJECTIVE

We sought to review the prevalence, diagnosis, neurobiology, and treatment of depression associated with congestive heart failure.

DATA SOURCES

A search of all English-language articles between January 2003 and January 2013 was conducted using the search terms congestive heart failure and depression.

STUDY SELECTION

We found 1,498 article abstracts and 19 articles (meta-analyses, systematic reviews, and original research articles) that were selected for inclusion, as they contained information about our focus on diagnosis, treatment, and pathophysiology of depression associated with congestive heart failure. The search was augmented with manual review of reference lists of articles from the initial search. Articles selected for review were determined by author consensus.

DATA EXTRACTION

The prevalence, diagnosis, neurobiology, and treatment of depression associated with congestive heart failure were reviewed. Particular attention was paid to the safety, efficacy, and tolerability of antidepressant medications commonly used to treat depression and how their side-effect profiles impact the pathophysiology of congestive heart failure. Drug-drug interactions between antidepressant medications and medications used to treat congestive heart failure were examined.

RESULTS

MDD is highly prevalent in patients with congestive heart failure. Moreover, the prevalence and severity of depression correlate with the degree of cardiac dysfunction and development of congestive heart failure. Depression increases the risk of congestive heart failure, particularly in those patients with coronary artery disease , and is associated with a poorer quality of life, increased use of health care resources, more frequent adverse clinical events and hospitalizations, and twice the risk of mortality.

CONCLUSIONS

At present, limited empirical data exist with regard to treatment of depression in the increasingly large population of patients with congestive heart failure. Evidence reveals that both psychotherapeutic treatment (eg, cognitive-behavioral therapy) and pharmacologic treatment (eg, use of the selective serotonin reuptake inhibitor sertraline) are safe and effective in reducing depression severity in patients with cardiovascular disease. Collaborative care programs featuring interventions that work to improve adherence to medical and psychiatric treatments improve both cardiovascular disease and depression outcomes. Depression rating scales such as the 9-item Patient Health Questionnaire should be used to monitor therapeutic efficacy.

From depression to neurodegeneration and heart failure: re-examining the potential of MAO inhibitors

Initially introduced in the 1950s for treating depression, monoamine oxidase (MAO) inhibitors were gradually abandoned, mainly owing to their potential for drug-drug and drug-food interactions, the most widely known being with tyramine-containing food (the 'cheese' effect). Since then, more selective MAO-A or MAO-B inhibitors have been developed with substantially reduced risks, and have been approved for the treatment of depression and Parkinson's disease, respectively. Recent research suggests that some of these drugs also have neuroprotective properties, while preclinical evidence expands the spectrum of potential indications to heart failure, renal diseases and multiple sclerosis. In this article, the authors review the relevance of MAO isoforms to disease, and they also outline current research and development efforts in this class of drugs, including newer multipotent compounds.

Transdermal patches for the treatment of neurologic conditions in elderly patients: a review

OBJECTIVE

The mode of drug delivery can be an important consideration in optimizing drug therapy, as it can affect treatment compliance and outcomes. It is particularly important to develop optimal drug formulations for chronic diseases or conditions in the elderly for which treatment compliance is known to be low. In this review, the features and benefits of transdermal formulations for treating neurologic conditions in elderly patients are described.

DATA SOURCES

English-language articles were identified by searching MEDLINE in November 2010 (there were no search parameters on date of publication) using the search terms transdermal patch, transdermal system, neurology, rivastigmine, rotigotine, selegiline, lidocaine, capsaicin, compliance, and neuropathic pain.

DATA SELECTION

Articles describing the development, use, efficacy, and safety of licensed transdermal patch treatments for neurologic conditions that affect the elderly were included.

DATA EXTRACTION

The features of transdermal systems and comparisons between transdermal and oral formulations for the treatment of specific neurologic conditions in elderly patients were reviewed.

DATA SYNTHESIS

There are 5 transdermal patch systems currently available for neurologic conditions in adults: rivastigmine, rotigotine, selegiline, lidocaine, and capsaicin. These are all modern formulations in matrix patches, developed to provide appropriate drug dosage in an acceptable and well-tolerated form.

CONCLUSIONS

Transdermal patches can offer benefits to patients over oral formulations in terms of ease of use, simple treatment regimens, avoidance of the first-pass effect, and avoidance of high maximum plasma concentrations with rapid changes in drug levels, without the invasive procedures associated with intravenous treatment.

Review of pharmacological treatment in mood disorders and future directions for drug development

After a series of serendipitous discoveries of pharmacological treatments for mania and depression several decades ago, relatively little progress has been made for novel hypothesis-driven drug development in mood disorders. Multifactorial etiologies of, and lack of a full understanding of, the core neurobiology of these conditions clearly have contributed to these development challenges. There are, however, relatively novel targets that have raised opportunities for progress in the field, such as glutamate and cholinergic receptor modulators, circadian regulators, and enzyme inhibitors, for alternative treatment. This review will discuss these promising new treatments in mood disorders, the underlying mechanisms of action, and critical issues of their clinical application. For these new treatments to be successful in clinical practice, it is also important to design innovative clinical trials that identify the specific actions of new drugs, and, ideally, to develop biomarkers for monitoring individualized treatment response. It is predicted that future drug development will identify new agents targeting the molecular mechanisms involved in the pathophysiology of mood disorders.

A review of the literature on the selegiline transdermal system: an effective and well-tolerated monoamine oxidase inhibitor for the treatment of depression

OBJECTIVE

To provide a narrative review of the properties of the selegiline transdermal system (STS) for the treatment of depression and its subtypes.

BACKGROUND

Monoamine oxidase inhibitors (MAOIs) once represented the mainstay of therapy for the treatment of major depressive disorder (MDD). However, despite their efficacy, these agents fell from favor due to the risk of acute hypertensive reactions following ingestion of foods containing high concentrations of tyramine. Recent efforts to develop MAOIs that overcome these limitations have resulted in the introduction of the first transdermal formulation of the MAOI selegiline for the treatment of MDD.

DATA SOURCES

A PubMed literature search was conducted in January 2007 using the keyword selegiline transdermal system.

STUDY SELECTION

Articles retrieved were reviewed and selected for inclusion based on their being randomized, double-blind, placebo-controlled studies that appeared between the years 2000 and 2007 and examined efficacy, safety, and tolerability data from clinical trials of patients with MDD who were treated with the STS. Four articles, including 3 acute trials and 1 long-term prevention of relapse trial, were included in this review based on these criteria.

CONCLUSIONS

The selegiline transdermal system provides several advantages compared to orally administered MAOIs, including minimal interaction with dietary tyramine and prolonged exposure to the parent compound, while offering a favorable side effect profile. As a result, treatment at the lowest effective dose of 6 mg/24 hours can be administered without the need for dietary modifications.

Blue again: perturbational effects of antidepressants suggest monoaminergic homeostasis in major depression

Some evolutionary researchers have argued that current diagnostic criteria for major depressive disorder (MDD) may not accurately distinguish true instances of disorder from a normal, adaptive stress response. According to disorder advocates, neurochemicals like the monoamine neurotransmitters (serotonin, norepinephrine, and dopamine) are dysregulated in major depression. Monoamines are normally under homeostatic control, so the monoamine disorder hypothesis implies a breakdown in homeostatic mechanisms. In contrast, adaptationist hypotheses propose that homeostatic mechanisms are properly functioning in most patients meeting current criteria for MDD. If the homeostatic mechanisms regulating monoamines are functioning properly in these patients, then oppositional tolerance should develop with prolonged antidepressant medication (ADM) therapy. Oppositional tolerance refers to the forces that develop when a homeostatic mechanism has been subject to prolonged pharmacological perturbation that attempt to bring the system back to equilibrium. When pharmacological intervention is discontinued, the oppositional forces cause monoamine levels to overshoot their equilibrium levels. Since depressive symptoms are under monoaminergic control, this overshoot should cause a resurgence of depressive symptoms that is proportional to the perturbational effect of the ADM. We test this prediction by conducting a meta-analysis of ADM discontinuation studies. We find that the risk of relapse after ADM discontinuation is positively associated with the degree to which ADMs enhance serotonin and norepinephrine in prefrontal cortex, after controlling for covariates. The results are consistent with oppositional tolerance, and provide no evidence of malfunction in the monoaminergic regulatory mechanisms in patients meeting current diagnostic criteria for MDD. We discuss the evolutionary and clinical implications of our findings.

Pharmacotherapy for late-life depression

The 2001 expert consensus guidelines for treating major depressive disorder (MDD) in geriatric patients recommended antidepressant treatment in combination with psychotherapy. Recent evidence continues to support the use of selective serotonin reuptake inhibitors and serotonin-norepinephrine reuptake inhibitors as first-line agents in the elderly, and although the transdermal monoamine oxidase inhibitor selegilene has shown promise in adult patients, it has not been studied in geriatric depression. Augmentation therapy with atypical antipsychotics or other agents may provide benefits for agitated, psychotic, or resistant MDD in the elderly. The few treatment studies that have been conducted in the geriatric population since the publication of the guidelines have had mixed results and high placebo response rates. More large controlled trials are needed.

Atypical depression: a comprehensive review

Despite several decades of research, the characteristics distinguishing atypical depression from other depressive subtypes remain ambiguous. Multiple lines of evidence support the designation of atypical depression as a scientifically and clinically relevant subtype, including differences in hormonal responses, brain laterality, psychological profile and psychiatric co-morbidity and differential treatment response. The evolution of the diagnostic criteria for atypical depression has led to the designation of mood reactivity as the cardinal feature, and the research supporting this conclusion is reviewed. This paper also reviews the evidence for the drug treatment of atypical depression, with a particular focus on research related to the superior efficacy of monoamine oxidase inhibitors (MAOIs) compared with tricyclic antidepressants (TCAs). Data relevant to the efficacy of newer antidepressants, including selective serotonin reuptake inhibitors (SSRIs), serotonin-noradrenaline (norepinephrine) reuptake inhibitors, transdermal selegiline and other new agents for atypical depression, are discussed. In summary, the diagnostic reliability and validity of atypical depression still remain elusive and open to further evolution. Currently available findings suggest that atypical depression has preferential response to MAOIs over TCAs. More data are required to determine the efficacy of newer agents relative to MAOIs and TCAs, although limited studies have shown a non-inferior efficacy and better tolerability of newer agents such as SSRIs compared with those of MAOIs and TCAs. Finally, future directions for research include further refinement of the diagnostic criteria for atypical depression, and clarification of the role of newer antidepressants in the treatment of this subtype with evidence from randomized, controlled trials.

Selegiline transdermal system: a novel treatment option for major depressive disorder

BACKGROUND

The use of monoamine oxidase inhibitors has declined owing to the risk of hypertensive crisis following the consumption of tyramine-rich foods and the consequent need for dietary tyramine restriction. However, owing to their superior efficacy in treating depression, continued efforts have been made to develop more selective and reversible monoamine oxidase inhibitors. Oral selegiline, at low doses, is a selective monoamine oxidase B (MAO-B) inhibitor, but at higher doses it loses its selectivity and can potentially interact with tyramine. Unfortunately, antidepressant effects of selegiline have been observed only at higher doses. The selegiline transdermal system was developed to deliver sustained selegiline blood concentrations sufficient to selectively inhibit MAO-A and MAO-B in the brain, producing antidepressant effects, without substantially inhibiting MAO-A in the gastrointestinal tract, thereby reducing the risk of hypertensive crisis.

OBJECTIVES

This article reviews the basic pharmacology, as well as efficacy and safety data of selegiline transdermal system for the treatment of depression.

CONCLUSIONS

Selegiline transdermal system is safe and effective in treating major depressive disorder at the dose range of 6 - 12 mg/24 h, without the need for dietary precautions at the 6 mg/24 h dose. No cases of hypertensive crisis were reported in clinical trials, even without dietary restrictions.

Skin tolerability associated with transdermal drug delivery systems: an overview

As transdermal patches become more widely prescribed, it is important that clinicians understand: (a) the common causes of skin reactions with these medications; (b) how to minimize these reactions; and (c) how to manage the signs and symptoms. Here we review published data for skin reactions with patch medications approved within the past decade. Overall, the most common application site signs and symptoms appear to be localized redness (erythema) or itching, sometimes accompanied by swelling (edema). Typically, these are mild to moderate in severity, transient in nature, and occur in 20% to 50% of patients. Most are localized to the area of application, and resolve spontaneously within several days following patch removal. Discontinuations due to these types of event are infrequent, ranging from 1.7% to 6.8% in the 6-month trials reviewed here. Based on expert opinion, the majority of these skin reactions would be a form of irritant contact dermatitis, with infrequent cases of allergic contact dermatitis. These types of reactions usually cause minimal pain or discomfort to the patient, and are unlikely to be of medical concern. Signs and symptoms of irritant contact dermatitis may be minimized by rotation of the application site, careful removal of the patch, and appropriate use of moisturizers and topical corticosteroids. In conclusion, the potential advantages of transdermal patches usually outweigh any additional skin issues; however, further research into treatment and management strategies is required.

Treatment-emergent sexual dysfunction related to antidepressants: a meta-analysis

BACKGROUND

Sexual dysfunction (SD) is an important underestimated adverse effect of antidepressant drugs. Patients, in fact, if not directly questioned, tend to scarcely report them. The aim of the present meta-analysis was to quantify SD caused by antidepressants on the basis of studies where sexual functioning was purposely investigated through direct inquiry and specific questionnaires.

METHODS

A literature search was conducted using MEDLINE, ISI Web of Knowledge, and references of selected articles. Selected studies performed on patients without previous SD were entered in the Cochrane Collaboration Review Manager (RevMan version 4.2). Our primary outcome measure was the rate of total treatment-emergent SD. Our secondary outcome measures were the rates of treatment-emergent desire, arousal, and orgasm dysfunction.

RESULTS

Our analyses indicated a significantly higher rate of total and specific treatment-emergent SD and specific phases of dysfunction compared with placebo for the following drugs in decreasing order of impact: sertraline, venlafaxine, citalopram, paroxetine, fluoxetine, imipramine, phenelzine, duloxetine, escitalopram, and fluvoxamine, with SD ranging from 25.8% to 80.3% of patients. No significant difference with placebo was found for the following antidepressants: agomelatine, amineptine, bupropion, moclobemide, mirtazapine, and nefazodone.

DISCUSSION

Treatment-emergent SD caused by antidepressants is a considerable issue with a large variation across compounds. Some assumptions, such as the inclusion of open-label studies or differences in scales used to assess SD, could reduce the significance of our findings. However, treatment-emergent SD is a frequent adverse effect that should be considered in clinical activity for the choice of the prescribed drug.

The selegiline transdermal system in major depressive disorder: a systematic review of safety and tolerability

BACKGROUND

Monoamine oxidase inhibitors (MAOIs) are highly efficacious antidepressants, but safety concerns have limited their broad use.

METHODS

We reviewed key safety and tolerability data from all clinical trials of patients with major depressive disorder (MDD) accrued during the clinical development of the selegiline transdermal system (STS), as reported to the Food and Drug Administration. This review includes data from both controlled and uncontrolled clinical trials involving STS-treated (n=2036) and placebo-treated (n=668) patients.

RESULTS

Except for the initial trial, subsequent trials, which involved STS doses ranging from 3 mg/24 h to 12 mg/24 h, lacked tyramine restrictions, and no acute hypertensive reactions occurred during study treatment. Safety experience with STS 6 mg/24 h supports this therapeutic dose without tyramine dietary modifications, but until more data are available for STS doses 9 mg/24 h and 12 mg/24 h, foods that are rich sources of tyramine should be avoided. The principal side effects of STS therapy were local dermal reactions and insomnia, both of which were dose-related. Side effects associated with MAOI treatment, such as sexual dysfunction and excessive weight gain, were uncommon.

CONCLUSIONS

A comprehensive review of safety from the clinical development program suggests that the STS is safe and well tolerated, with an improved safety margin compared with orally administered MAOIs.

Selegiline transdermal system in the treatment of depressive disorders

Selegiline is a selective irreversible inhibitor of monoamine oxidase (MAO)-B during low-dose oral treatment. Additional MAO-A inhibition occurs in higher dose ranges. Selegiline transdermal system (STS) shows a more potent MAO inhibition in comparison with orally administered selegiline, and at minimum doses of 20 mg/20 cm2 patch delivering 6 mg/24 h, no dietary restrictions, including low-tyramine food, are necessary. While oral selegiline has been used for years in the treatment of Parkinson’s disease, the US FDA recently approved the STS for use in treating major depression. Data from three randomized controlled trials showed a significantly better efficacy of STS in the treatment of unipolar major depression in comparison with placebo during 6–8 weeks of treatment. In addition, one long-term randomized controlled trial demonstrated the efficacy of the STS in relapse prevention of unipolar depression over 1 year. A total number of 515 depressed patients received STS during these studies. The tolerability profile of STS without dietary restrictions was excellent. The only side effects that were more frequent than with placebo were application-site reactions. No change in vital parameters and no hypertensive crisis have been recorded. Comparative studies including treatment with established antidepressants and the investigation of bipolar depressed patients and of specific patient subgroups (e.g., anergic and atypical depression) have to follow. The combination of the well-known effectiveness of irreversible MAO inhibitors with a good tolerability profile and a new pharmaceutical form, possibly enhancing compliance, represents a promising further expansion of the pharmacotherapeutic repertoire in the treatment of depression.

Pharmacokinetics and absolute bioavailability of selegiline following treatment of healthy subjects with the selegiline transdermal system (6 mg/24 h): a comparison with oral selegiline capsules

The selegiline transdermal system is a monoamine oxidase inhibitor that was recently approved by the US Food and Drug Administration for the treatment of major depressive disorder. The current study was conducted during the selegiline transdermal system development program to characterize the single-dose pharmacokinetics and absolute bioavailability of selegiline administered by the 6-mg/24-h selegiline transdermal system in healthy volunteers. Selegiline transdermal system results were compared with those obtained after a single 10-mg oral dose of selegiline HCl. The selegiline pharmacokinetics differed greatly between the 2 routes of administration. Transdermal selegiline administration reduced metabolism and produced a high, sustained plasma selegiline concentration over the dosing period, with an absolute bioavailability of 73%. By contrast, oral dosing produced a sharp plasma selegiline peak that occurred within 1 hour and declined rapidly, with an absolute bioavailability of 4%. The data provide the basis for therapeutic advantages of the selegiline transdermal system in administering antidepressant doses of selegiline.

Selegiline transdermal system: current awareness and promise

Many monoamine oxidase inhibitors (MAOIs) have been used to treat major depressive disorder (MDD). However, the prescription of MAOIs has decreased considerably as a result of side effects such as tyramine-induced hypertensive crisis, which is also known as the 'Cheese Effect'. The drug delivery system itself can affect the bioavailability of certain drugs, which might influence the efficacy and tolerability of medications, as well as improve the compliance and reduce the incidence of recurrence and relapse. Therefore, there is a need for advanced drug delivery techniques that can evade the potentially hazardous toxic effects of the parent compound, including extended-release oral, cutaneous, intravesical and intravaginal routes, etc. In this context, the selegiline transdermal system (STS, EMSAM) was introduced with improved side effect profiles and efficacy compared with the conventional form of the selegiline oral tablet. STS allows the targeted inhibition of the monoamine A (MAO-A) and MAO-B isoenzymes with minimal effects on the MAO-A in the gastrointestinal and hepatic systems. Hence, STS can reduce the risk of interactions with tyramine-rich foods. Many fundamental clinical and preclinical studies have reported that 6 mg/24 h of STS is effective against MDD without the need for dietary restrictions with an equal efficacy and improved safety profile. In addition, STS might benefit MDD patients with atypical features or who are resistant to other antidepressants. Overall, familiarity with the properties and indications of STS will have the clinicians another option of biological treatments for MDD patients but subsequent more data including actual post-market clinical experiences will be mandatory.

Evaluation of the potential for pharmacodynamic and pharmacokinetic drug interactions between selegiline transdermal system and two sympathomimetic agents (pseudoephedrine and phenylpropanolamine) in healthy volunteers

Selegiline transdermal system is a recently approved monoamine oxidase inhibitor antidepressant. Medications that inhibit monoamine oxidase type A can augment the pressor effects of sympathomimetic amines, increasing the potential for hypertensive crisis. This study examined the potential for drug-drug interactions during treatment with selegiline transdermal system and pseudoephedrine or phenylpropanolamine. Two studies were conducted with 25 healthy volunteers to assess changes in blood pressure and heart rate during administration of pseudoephedrine or phenylpropanolamine alone or together with selegiline transdermal system. No significant differences in mean maximum changes in vital signs occurred with pseudoephedrine. No significant differences were found in mean maximum changes in systolic heart rate with phenylpropanolamine; however, 4 of 12 subjects each experienced 1 isolated protocol-defined minimal pressor response without concurrent adverse effects (1 with phenylpropanolamine alone; 3 with phenylpropanolamine + selegiline transdermal system). Pharmacokinetic parameters obtained following selegiline transdermal system and pseudoephedrine or phenylpropanolamine were unremarkable. The results suggest that selegiline transdermal system 6 mg/24 h does not significantly alter the pharmacodynamics or pharmacokinetics of either pseudoephedrine or phenylpropanolamine when administered to healthy volunteers; however, it is prudent to avoid coadministration of selegiline transdermal system and sympathomimetics.

Selegiline transdermal system: in the treatment of major depressive disorder

The monamine oxidase (MAO) inhibitor selegiline is selective for MAO-B at the low oral dosages used in the treatment of Parkinson's disease. However, MAO-A is also inhibited at the high oral dosages needed to effectively treat depression (not an approved indication), necessitating a tyramine-restricted diet. The selegiline transdermal system was designed to deliver antidepressant drug concentrations to the CNS, without substantially impairing small intestine MAO-A activity. At the target dose of 6 mg/24 hours, tyramine dietary restrictions are not needed. Short-term treatment with fixed (6 mg/24 hours) or flexible (6, 9 or 12 mg/24 hours) doses of selegiline transdermal system was superior to placebo on most measures of antidepressant activity in 6- or 8-week, randomised, double-blind, multicentre studies in adult outpatients with major depressive disorder (MDD). Likewise, long-term treatment with a fixed dose of selegiline transdermal system 6 mg/24 hours was superior to placebo as maintenance therapy in a 52-week, randomised, double-blind, multicentre, relapse-prevention trial in patients with MDD. Selegiline transdermal system therapy was generally well tolerated in placebo-controlled studies; application site reactions, mostly of mild to moderate severity, were the most commonly reported adverse events. The incidence of sexual adverse effects and weight gain was low and similar to that with placebo.