The effects of agomelatine on sexual function in depressed patients and healthy volunteers

The effect of drug holidays on sexual dysfunction in men treated with selective serotonin reuptake inhibitors (SSRIs) other than fluoxetine: an 8-week open-label randomized clinical trial

INTRODUCTION

Selective serotonin reuptake inhibitors (SSRIs) are widely used for the treatment of various mental disorders. Sexual dysfunction is one of the most common side effects of SSRIs, and often leads to poor adherence and treatment discontinuation. While several strategies have been employed to manage SSRI-induced sexual dysfunction, drug holidays has not been extensively studied for this purpose. This clinical trial aims to assess the effect of drug holidays on sexual dysfunction in married men under treatment with SSRIs other than fluoxetine (as its long half-life makes drug holidays ineffective).

METHODS

This 8-week double-center, randomized, open-label, controlled trial was conducted in the outpatient clinics of Iran Psychiatric Hospital and Tehran Institute of Psychiatry, from January 2022 to March 2023. We included married men aged between18 and 50 years who had experienced sexual dysfunction during treatment with SSRIs, other than fluoxetine. The Male Sexual Health Questionnaire (MSHQ) and the 28-Question General Health Questionnaire (GHQ-28) were used for the assessment of sexual function and mental health status. The drug holidays group was instructed not to take their medications on the weekends. The control group was asked to continue their regular medication regimen without any changes. Both groups were assessed at baseline, and weeks 4 and 8.

RESULTS

Sixty-three patients were included and randomly assigned to the drug holidays group (N = 32) or the control group (N = 31). Fifty patients (25 in each group) completed the trial. Drug holidays significantly improved erection, ejaculation, satisfaction, and the overall sexual health of the participants (P < 0.001). No significant change was observed in their mental health status. No major side effects were recorded.

CONCLUSIONS

Drug holidays significantly improved the MSHQ scores in 'erection', 'ejaculation', 'satisfaction' and 'total' in married men with sexual dysfunction induced by SSRIs, other than fluoxetine, without causing any significant changes in their mental health status. Further research is needed to reach a certain conclusion.

TRIAL REGISTRATION

The trial was registered at the Iranian Registry of Clinical Trials on 2021.10.25 ( www.irct.ir ; IRCT ID: IRCT20170123032145N6) before the trial.

Efficacy of repetitive transcranial magnetic stimulation and agomelatine on sleep quality and biomarkers of adult patients with mild to moderate depressive disorder

BACKGROUND

Mild to moderate depressive disorder (DD), which accounts for much larger patient population, has been largely neglected in previous studies exploring the sleep quality of DD patients; in addition, most of these patients had comorbid insomnia. Thus, this study aimed to explore the effect of repetitive transcranial magnetic stimulation (rTMS) and agomelatine on sleep quality of adult patients with mild to moderate DD.

METHODS

100 participants were randomly divided into high-frequency rTMS group and sham rTMS group (n = 50 each). All patients were administered agomelatine simultaneously. Hamilton Depression Scale-17 Items (HAMD-17), Pittsburgh Sleep Index (PSQI), and polysomnography were used to evaluate the efficacy. Serum norepinephrine (NE), 5-hydroxytryptamine, brain-derived neurotrophic factor (BDNF), and melatonin were also determined.

RESULTS

The HAMD-17 and PSQI scores in high-frequency rTMS group were lower than those in sham rTMS group at the 4th and 8th weekend after treatment (P < 0.05). Post-treatment total sleep time, sleep efficiency, and N3 percentage in high-frequency rTMS group were better than those in sham rTMS group (P < 0.05); while post-treatment sleep latency, awakening time, micro-awakening times, and N1 percentage were significantly less than those in sham rTMS group (P < 0.01). Post-treatment serum levels of NE and BDNF in high-frequency rTMS group were higher than those in sham rTMS group (P < 0.05).

LIMITATIONS

Small sample size and short follow-up duration.

CONCLUSION

The combination of high-frequency rTMS and agomelatine is effective in the treatment of mild to moderate DD, which can improve the sleep quality and increase the levels of some neurotransmitters and neurotrophic factors.

[Sexual dysfunction on the background of antidepressant therapy]

The review is devoted to the problem of sexual dysfunction caused by taking antidepressants. Sexual dysfunction is widespread, but it is not reported, and its impact on the quality of life and compliance of patients is underestimated. Partly because of its bidirectional association with depression, sexual dysfunction is difficult to diagnose. Possible mechanisms and risk factors associated with sexual dysfunction in patients with depression are considered. The data on the frequency of sexual dysfunction with the use of various antidepressants are given. Therapeutic strategies for sexual dysfunction associated with taking antidepressants are described. The advantages of agomelatin as an antidepressant associated with a low risk of sexual side effects are emphasized.

Agomelatine in the treatment of anhedonia, somatic symptoms, and sexual dysfunction in major depressive disorder

Objective

This study evaluated the treatment outcomes of agomelatine on anhedonic state, anxiety/somatic symptoms, and sexual function in Chinese patients with major depressive disorder (MDD).

Method

In total, 93 adult patients with MDD were enrolled, and 68 of them were included in a prospective, open-label, multicenter clinical study. All patients received agomelatine monotherapy during a 9-week treatment phase. The effectiveness of the treatment was reflected by the improvement of anhedonia and somatic symptoms based on the 17-item Hamilton Depression Rating Scale (HAMD-17). In addition, the Arizona Sexual Dysfunction Scale (ASEX), Sheehan Disability Scale (SDS), and Short Form of Quality-of-Life Enjoyment and Satisfaction Questionnaire (Q-LES-Q-SF) were administered to all participants at baseline and at the 3-, 6-, and 9-week follow-ups.

Results

After 9 weeks of treatment with agomelatine, the response and remission rates were 73.5% and 39.7%, respectively. Somatic symptoms significantly improved at week 9 (p < 0.001), and significant effects were also observed on the HAMD anhedonia items (p < 0.001). The patients exhibited lower levels of disease severity (the SDS score dropped from 15.52 ± 4.7 to 7.09 ± 5.62 at week 9; the ASEX score dropped from 21.89 ± 4.06 to 16.19 ± 4.79, p < 0.001) and higher levels of QOL (the Q-LES-Q-SF score dropped from 41.02 ± 5.99 to 50.49 ± 8.57, p < 0.001) during the follow-up. Furthermore, treatment with agomelatine improved depressive symptoms without causing serious adverse events.

Conclusion

These analyses indicate that agomelatine is a treatment option for improving anhedonic status, anxiety/somatic symptoms, and sexual dysfunction in MDD patients.

Agomelatine for the treatment of generalized anxiety disorder: focus on its distinctive mechanism of action

Generalized anxiety disorder (GAD), the most frequently diagnosed form of anxiety, is usually treated by cognitive-behavioural approaches or medication; in particular, benzodiazepines (acutely) and serotonin or serotonin/noradrenaline reuptake inhibitors (long term). Efficacy, compliance, and acceptability are, however, far from ideal, reinforcing interest in alternative options. Agomelatine, clinically employed in the treatment of major depression, expresses anxiolytic properties in rodents and was effective in the treatment of GAD (including severely ill patients) in several double-blind, short-term (12 weeks) and relapse-prevention (6 months) studies. At active doses, the incidence of adverse effects was no higher than for placebo. Agomelatine possesses a unique binding profile, behaving as a melatonin (MT₁/MT₂) receptor agonist and 5-HT_2C receptor antagonist, yet recognizing neither monoamine transporters nor GABA_A receptors. Extensive evidence supports a role for 5-HT_2C receptors in the induction of anxious states, and their blockade likely plays a primary role in mediating the anxiolytic actions of agomelatine, including populations in the amygdala and bed nucleus of stria terminalis, as well as the hippocampus. Recruitment of MT receptors in the suprachiasmatic nucleus, thalamic reticular nucleus, and hippocampus appears to fulfil a complimentary role. Downstream of 5-HT_2C and MT receptors, modulation of stress-sensitive glutamatergic circuits and altered release of the anxiogenic neuropeptides, corticotrophin-releasing factor, and vasopressin, may be implicated in the actions of agomelatine. To summarize, agomelatine exerts its anxiolytic actions by mechanisms clearly distinct from those of other agents currently employed for the management of GAD.

PLAIN LANGUAGE SUMMARY

How agomelatine helps in the treatment of anxiety disorders.

INTRODUCTION

• Anxiety disorders have a significant negative impact on quality of life.• The most common type of anxiety disorder, called generalized anxiety disorder (GAD), is associated with nervousness and excessive worry.• These symptoms can lead to additional symptoms like tiredness, sleeplessness, irritability, and poor attention.• GAD is generally treated through either cognitive-behavioural therapy or medication. However, widely used drugs like benzodiazepines and serotonin reuptake inhibitors have adverse effects.• Agomelatine, a well-established antidepressant drug, has shown anxiety-lowering ('anxiolytic') properties in rats and has been shown to effectively treat GAD with minimal side effects.• However, exactly how it acts on the brain to manage GAD is not yet clear.• Thus, this review aims to shed light on agomelatine's mechanism of action in treating GAD.

METHODS

• The authors reviewed studies on how agomelatine treats anxiety in animals.• They also looked at clinical studies on the effects of agomelatine in people with GAD.

RESULTS

• The study showed that agomelatine 'blocks' a receptor in nerve cells, which plays a role in causing anxiety, called the 5-HT_2C receptor.• Blocking this receptor, especially in specific brain regions such as nerve cells of the amygdala, bed nucleus of stria terminalis, and hippocampus, produced the anxiety reduction seen during agomelatine treatment.• Agomelatine also activates the melatonin (MT) receptor, which is known to keep anxiety in check, promote sleep, and maintain the sleep cycle.• Agomelatine should thus tackle sleep disturbances commonly seen in patients with GAD.• Beyond 5-HT_2C and MT receptors, signalling molecules in nerve cells that are known to be involved in anxiety disorders (called 'neurotransmitters' and 'neuropeptides') are also affected by agomelatine.

CONCLUSION

• Agomelatine's anxiolytic effects are caused by mechanisms that are distinct from those of other medications currently used to treat GAD.• This explains its therapeutic success and minimal adverse side effects.

Validation of the Oxford Depression Questionnaire: Sensitivity to change, minimal clinically important difference, and response threshold for the assessment of emotional blunting

BACKGROUND

The Oxford Depression Questionnaire (ODQ) is a patient-reported scale for assessing emotional blunting in patients with major depressive disorder (MDD). This analysis was undertaken to further validate the scale in patients experiencing emotional blunting while receiving antidepressant treatment.

METHODS

Patients with MDD who experienced inadequate depressive-symptom resolution and emotional blunting on selective serotonin reuptake inhibitor or serotonin-noradrenaline reuptake inhibitor monotherapy (adequate dose for ≥6 weeks) were switched to vortioxetine 10-20 mg/day. ODQ total scores were assessed excluding and including the "antidepressant-as-cause" domain (ODQ-20 and ODQ-26, respectively). Anchor- and distribution-based methods were used to determine the minimal clinically important difference in ODQ scores in terms of change from baseline to week 8 of antidepressant treatment.

RESULTS

After 8 weeks of vortioxetine treatment, the mean change in ODQ-20 and ODQ-26 scores from baseline was -24.8 and -30.1 points, respectively. Greater mean changes from baseline in ODQ-20 and ODQ-26 scores were seen in patients reporting no emotional blunting vs those still experiencing emotional blunting after 8 weeks of vortioxetine treatment (ODQ-20: -27.0 vs -22.6 points; ODQ-26: -32.8 vs -27.5 points, respectively). In patients considered clinically minimally improved (Clinical Global Impression-Improvement score, 3) after 8 weeks of vortioxetine treatment, respective mean (standard deviation) change in ODQ-20 and ODQ-26 score from baseline was -15.5 (18.1) and -20.0 (20.5) points.

LIMITATIONS

Short study duration.

CONCLUSIONS

These results provide further validation of the clinical utility of the ODQ for assessing emotional blunting in patients with MDD. The suggested minimal clinically important difference for change in ODQ-20 and ODQ-26 scores is 16 and 20 points, respectively, after 8 weeks of antidepressant treatment.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT03835715.

Agomelatine in Standard Medical Practice in Depressed Patients: Results of a 1-Year Multicentre Observational Study In France

Background and Objectives

Non-interventional studies are a valuable source of evidence that is complementary to traditional randomised, blinded and controlled clinical trials, for evaluating antidepressants in a real-world setting. The aim of the present study was to document the use of agomelatine in current medical practice and evaluate its effectiveness and safety in outpatients prescribed agomelatine to treat their current depressive episode.

Methods

This 12-month observational French study included patients initiating agomelatine treatment. The intensity and severity of depression were assessed using the 17-item Hamilton Depression Rating Scale (HAM-D17) total score and the Clinical Global Impression-Severity of Illness (CGI-S) scale. Patients’ quality of life and functioning were measured using the Quality of Life in Depression Scale and the Sheehan Disability Scale, respectively. The safety measures included emergent adverse events and biological samplings, with a focus on liver acceptability.

Results

A total of 1484 patients (70% of women; 49.6 ± 15.4 years of age) were enrolled in the study. Most patients (62.3%) were treated with agomelatine for at least 6 months and 28.8% were treated for at least 1 year. Mean HAM-D17 total score and mean CGI-S scores decreased by 13.6 ± 8.1 and 2.1 ± 1.5 points, respectively, from baseline to last visit on agomelatine. Rates of responders (i.e. with a decrease in HAM-D17 total score by at least 50%) and remitters (HAM-D total score < 7) at the last visit were 90.7% and 56.0%, respectively. The mean HAM-D total score decreased after agomelatine withdrawal (− 4.1 ± 6.7) until the last visit. The quality of life and daily functioning of patients improved, while the numbers of days lost and underproductive days decreased over the follow-up period. Safety findings were in accordance with the known information regarding agomelatine.

Conclusion

In the current medical practice, this study confirms the effectiveness and good tolerability of agomelatine administered for a treatment period in agreement with guideline recommendations.

Trial registration number

ISRCTN53570733 on 27 August 2010.

The preclinical discovery and development of agomelatine for the treatment of depression

INTRODUCTION

Under the treatment of commonly used antidepressants, many patients with major depressive disorder (MDD) do not achieve remission. All previous first-line treatments for depression have focused on the enhancement of monoaminergic activity. Agomelatine was the first antidepressant with a mechanism of action extending beyond monoaminergic neurotransmission.

AREAS COVERED

The aim of this case history is to describe the discovery strategy and development of agomelatine. The pharmacodynamic profile of the drug is briefly presented. The article summarizes (a) the preclinical behavioral data on agomelatine's effects on depressive-like behavior, anxiety, and circadian rhythmicity disruptions, and (b) the results of early preclinical studies on safety, efficacy in MDD, and the risk-benefit pharmacological profile. Furthermore, the article examines findings of post-marketing research on safety, efficacy, and cost-effectiveness of the drug.

EXPERT OPINION

There is now evidence supporting the clinical efficacy and safety profile of agomelatine in the acute-phase treatment of MDD. Agomelatine may be more effective in specific subgroups of MDD patients, those with severe anxiety symptoms or disturbed circadian profiles. Its antidepressant and anxiolytic activities are due to synergy between its melatonergic and 5-hydroxytryptaminergic effects. Since its discovery, novel compounds acting on the melatonergic system have been under investigation for the treatment of MDD.

Antidepressant-induced sexual dysfunction

Sexual dysfunction is a frequent, potentially distressing, adverse effect of antidepressants and a leading cause of medication non-adherence. Sexual function should be actively assessed at baseline, at regular intervals during treatment, and after treatment cessation. Trials comparing the risk of sexual dysfunction with individual antidepressants are inadequate, but it is reasonable to conclude that the risk is greatest with selective serotonin reuptake inhibitors (SSRIs) and serotonin and noradrenaline reuptake inhibitors (SNRIs), less with tricyclic antidepressants (except clomipramine) and mirtazapine, and least with moclobemide, agomelatine, reboxetine and bupropion. Management of antidepressant-induced sexual dysfunction requires an individualised approach (eg, considering other causes, dose reduction, addition of medication to treat the adverse effect, switching to a different antidepressant). Post-SSRI sexual dysfunction has been recently identified as a potential, although rare, adverse effect of SSRIs and SNRIs. Consider the possibility of post-SSRI sexual dysfunction in patients in whom sexual dysfunction was absent before starting antidepressants but develops during or soon after antidepressant treatment and still persists after remission from depression and discontinuation of the drug.

Management Strategies for Antidepressant-Related Sexual Dysfunction: A Clinical Approach

Major depressive disorder is a serious mental disorder in which treatment with antidepressant medication is often associated with sexual dysfunction (SD). Given its intimate nature, treatment emergent sexual dysfunction (TESD) has a low rate of spontaneous reports by patients, and this side effect therefore remains underestimated in clinical practice and in technical data sheets for antidepressants. Moreover, the issue of TESD is rarely routinely approached by clinicians in daily praxis. TESD is a determinant for tolerability, since this dysfunction often leads to a state of patient distress (or the distress of their partner) in the sexually active population, which is one of the most frequent reasons for lack of adherence and treatment drop-outs in antidepressant use. There is a delicate balance between prescribing an effective drug that improves depressive symptomatology and also has a minimum impact on sexuality. In this paper, we detail some management strategies for TESD from a clinical perspective, ranging from prevention (carefully choosing an antidepressant with a low rate of TESD) to possible pharmacological interventions aimed at improving patients’ tolerability when TESD is present. The suggested recommendations include the following: for low sexual desire, switching to a non-serotoninergic drug, lowering the dose, or associating bupropion or aripiprazole; for unwanted orgasm delayal or anorgasmia, dose reduction, “weekend holiday”, or switching to a non-serotoninergic drug or fluvoxamine; for erectile dysfunction, switching to a non-serotoninergic drug or the addition of an antidote such as phosphodiesterase 5 inhibitors (PD5-I); and for lubrication difficulties, switching to a non-serotoninergic drug, dose reduction, or using vaginal lubricants. A psychoeducational and psychotherapeutic approach should always be considered in cases with poorly tolerated sexual dysfunction.

Frequency of Sexual Dysfunction in Patients Treated with Desvenlafaxine: A Prospective Naturalistic Study

Despite being clinically underestimated, sexual dysfunction (SD) is one of the most frequent and lasting adverse effects associated with antidepressants. Desvenlafaxine is an antidepressant (AD) with noradrenergic and serotonergic action that can cause a lower SD than other serotonergic ADs although there are still few studies on this subject. Objective: To check the frequency of SD in two groups of depressive patients: one group was desvenlafaxine-naïve; the other was made up of patients switched to desvenlafaxine from another AD due to iatrogenic sexual dysfunction. A naturalistic, multicenter, and prospective study of patients receiving desvenlafaxine (50–100 mg/day) was carried out on 72 patients who met the inclusion criteria (>18 years old and sexually active), who had received desvenlafaxine for the first time (n = 27) or had switched to desvenlafaxine due to SD with another AD (n = 45). Patients with previous SD, receiving either drugs or presenting a concomitant pathology that interfered with their sexual life and/or patients who abused alcohol and/or drugs were excluded. We used the validated Psychotropic-Related Sexual Dysfunction Questionnaire (PRSexDQ-SALSEX) to measure AD-related sexual dysfunction and the Clinical Global Impression Scale for psychiatric disease (CGI-S) and for sexual dysfunction (CGI-SD) at two points in time: baseline and three months after the commencement of desvenlafaxine treatment. Results: In desvenlafaxine-naïve patients, 59.2% of the sample showed moderate/severe sexual dysfunction at baseline, which was reduced to 44% at follow-up. The PSexDQ-SALSEX questionnaire total score showed a significant improvement in sexual desire and sexual arousal without changes in orgasmic function at follow-up (p < 0.01). In the group switched to desvenlafaxine, the frequency of moderate/severe SD at baseline (93.3%) was reduced to 75.6% at follow-up visit. Additionally, SD significantly improved in three out of four items of the SALSEX: low desire, delayed orgasm, and anorgasmia at follow-up (p < 0.01), but there was no significant improvement in arousal difficulties. The frequency of severe SD was reduced from 73% at baseline to 35% at follow-up. The CGI for psychiatric disease and for sexual dysfunction improved significantly in both groups (p < 0.01). There was a poor tolerability with risk of treatment noncompliance in 26.7% of patients with sexual dysfunction due to another AD, this significantly reduced to 11.1% in those who switched to desvenlafaxine (p = 0.004). Conclusion: Sexual dysfunction improved significantly in depressed patients who initiated treatment with desvenlafaxine and in those who switched from another AD to desvenlafaxine, despite this, desvenlafaxine treatment is not completely devoid of sexual adverse effects. This switching strategy could be highly relevant in clinical practice due to the significant improvement in moderate/severe and poorly tolerated SD, while maintaining the AD efficacy.

A Real-World Study on Antidepressant-Associated Sexual Dysfunction in 2144 Outpatients: The SALSEX I Study

The objective of this cross-sectional study was to evaluate the frequency, impact, and management of sexual dysfunction associated with commonly prescribed antidepressants available in psychiatry outpatient clinics in Spain. We recruited 2163 adult patients who had undergone treatment with antidepressants for at least 8 weeks and had a history of normal sexual functioning before the prescription of the antidepressant, except for mildly impaired libido. We used the Psychotropic-Related Sexual Dysfunction Questionnaire (PRSexDQ-SALSEX) for evaluating the frequency and tolerance of sexual dysfunction and whether this side effect was spontaneously reported. Overall, 79% patients showed sexual dysfunction, as indicated by a total score ≥ 3 on the PRSexDQ-SALSEX; 64% showed moderate-severe sexual dysfunction, with no differences between men and women on these outcomes. In the multivariate logistic regression analysis, treatment with a serotonergic antidepressant and having a severe clinical state of psychiatric illness were the factors associated with the highest likelihood of presenting with sexual dysfunction. Sexual dysfunction was spontaneously reported by 838 (41%) of the 2066 evaluable patients for this outcome. Among patients with sexual dysfunction, this condition was poorly tolerated by 22% of the patients, with these frequencies being significantly higher in men than in women. The most frequently used strategies employed by the psychiatrists in our study for dealing with sexual dysfunction were switching to another antidepressant (34%) and waiting for spontaneous resolution (33%). In conclusion, our results indicate that despite being a well-known, long-standing side effect of antidepressants, sexual dysfunction continues to be extremely common in patients receiving antidepressants, especially serotonergic ones, potentially jeopardizing treatment success in a substantial proportion of patients. There are important sex differences in the reporting and tolerance of sexual dysfunction that require further investigation.

Agomelatine for depression: expanding the horizons?

INTRODUCTION

Agomelatine is an antidepressant with unique pharmacological actions; it is both a melatonin agonist and selective serotonin antagonist. Both actions combined are necessary for antidepressant efficacy. Effects on melatonin receptors enable resynchronisation of disrupted circadian rhythms with beneficial effects on sleep patterns. Areas covered: The issue of use of an antidepressant for depression co-morbid with somatic disorders is covered by the authors. A review of the literature from 2000 to August 2018 was undertaken using Scopus and Web of Science with the key words: agomelatine, depression, medical illness. Depression in Parkinson's disease, cardiovascular illness and type II diabetes is reviewed with evidence of efficacy. Bipolar depression and seasonal affective disorder may also react favourably. Agomelatine may have specific efficacy on symptoms of anhedonia. Expert opinion: Despite approval in some major jurisdictions, the drug has failed to gain registration in the United States. A defining issue may be questions about longer term efficacy: unequivocal effectiveness in placebo-controlled relapse prevention studies has not always been demonstrated. Continuation studies suggest maintenance of clinical responsiveness. A major disadvantage of the drug is its' potential hepatotoxicity and the need for repeated clinical laboratory tests.

Understanding the Mechanism of Antidepressant-Related Sexual Dysfunction: Inhibition of Tyrosine Hydroxylase in Dopaminergic Neurons after Treatment with Paroxetine but Not with Agomelatine in Male Rats

Antidepressant-related sexual dysfunction is a frequent adverse event caused by serotonergic activation that intensely affects quality of life and adherence in depressed patients. The dopamine system has multiple effects promoting sexual behavior, but no studies have been carried out to confirm dopaminergic changes involved in animal models after antidepressant use. Methods: The sexual behavior-related dopaminergic system in the rat was studied by comparing two different antidepressants and placebo for 28 days. The antidepressants used were paroxetine (a serotonergic antidepressant that causes highly frequent sexual dysfunction in humans) and agomelatine (a non-serotonergic antidepressant without associated sexual dysfunction). The tyrosine hydroxylase immunoreactivity (THI) in the substantia nigra pars compacta, the ventral tegmental area, the zona incerta, and the hypothalamic arcuate nucleus, as well as the dopaminergic projections to the striatum, hippocampus, cortex, and median eminence were analyzed. Results: The THI decreased significantly in the substantia nigra and ventral tegmental area after treatment with paroxetine, and the labeling was reduced drastically in the zona incerta and mediobasal hypothalamus. The immunoreactive axons in the target regions (striatum, cortex, hippocampus, and median eminence) almost disappeared only in the paroxetine-treated rats. Conversely, after treatment with agomelatine, a moderate reduction in immunoreactivity in the substantia nigra was found without appreciable modifications in the ventral tegmental area, zona incerta, and mediobasal hypothalamus. Nevertheless, no sexual or copulatory behavior was observed in any of the experimental or control groups. Conclusion: Paroxetine but not agomelatine was associated with important decreased activity in dopaminergic areas such as the substantia nigra and ventral tegmental areas that could be associated with sexual performance impairment in humans after antidepressant treatment.

What combinations of agomelatine with other antidepressants could be successful during the treatment of major depressive disorder or anxiety disorders in clinical practice?

Even with many antidepressant and anxiolytic drugs available on the market, there are still patients who do not respond well to the standard first or second line treatments for affective or anxiety disorders. The antidepressant agomelatine has been used in Europe for several years. Agomelatine, an agonist at melatonin receptors and an antagonist at serotonin receptors, can be particularly useful in patients suffering from a major depressive disorder associated with insomnia. Some clinical data have shown a limited effect for agomelatine in a subset of patients with major depression. A number of case reports published in 2011-2016 describe the effect of agomelatine in combination with an established antidepressant, such as escitalopram, venlafaxine, duloxetine, moclobemide or bupropion. A successful combination of agomelatine was reported after adjunctive use of agomelatine combined with clomipramine, escitalopram, and venlafaxine in patients with major depression or obsessive-compulsive disorder. Moreover, bupropion or moclobemide augmentation with agomelatine in patients with major depressive disorder led to a significant improvement. Other supportive data have been published, such as analysis of the VIVALDI study, although it should be noted that the study was supported by the manufacturer of agomelatine. In this study, agomelatine in combination with other antidepressants was shown to be effective and well tolerated in practice, although the most effective antidepressant treatment in the study consisted of agomelatine alone and not in combination with other antidepressants. There have also been two published case reports about the concomitant use of duloxetine and agomelatine which were not efficacious. The positive results of agomelatine augmentation with other antidepressants should be confirmed through randomized, double-blind clinical trials.

Efficacy and Safety of Agomelatine vs Paroxetine Hydrochloride in Chinese Han Patients with Major Depressive Disorder: A Multicentre, Double-Blind, Noninferiority, Randomized Controlled Trial

PURPOSE

The purpose of this study is to investigate the efficacy, safety, and tolerability of agomelatine and paroxetine in Chinese Han patients with major depressive disorder (MDD).

METHODS

A 8-week, double-blind, randomized, parallel study was conducted in 14 medical centers in mainland China from December 2011 to September 2012. A total of 264 subjects with a primary Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition diagnosis of MDD were randomly assigned to receive agomelatine 25-50 mg/d (n = 132) or paroxetine 20-40 mg/d (n = 132). The primary efficacy was evaluated by the decrease of Hamilton Depression Rating Scale (HAM-D17) scores. The secondary measurements of efficacy included Hamilton Anxiety Rating Scale, Montgomery-Asberg Depression Rating Scale, Sheehan Disability Scale, Clinical Global Impressions-Severity, and Clinical Global Impressions-Improvement. The laboratory test abnormity, and observed and self-reported adverse events were all assessed as the measurements of safety and tolerability.

RESULTS

Both the agomelatine and paroxetine groups showed significant improvement from baseline to the end point (P < 0.05) without between-group differences (P > 0.05). The mean decrease of HAM-D17 of agomelatine group was not inferior to the paroxetine group over the 8-week treatment (agomelatine 15.26 ± 6.44 vs paroxetine 14.87 ± 5.89, δ = 2.0; μA-μB 95% confidence interval, -1.13 to 1.91). The percentage of responders at the last postbaseline assessment was similar in the 2 groups on both HAM-D17 (agomelatine 66.15% vs paroxetine 63.49%) and Clinical Global Impressions-Improvement (agomelatine 79.09% vs paroxetine 80.36%). The anxiety (Hamilton Anxiety Rating Scale) and sleep symptoms (sleep items of HAM-D17) of the patients were improved significantly in the 2 groups at week 8 without between-group differences (P > 0.05). The incidence of overall adverse events was similar in the 2 groups (agomelatine 49.62% vs paroxetine 56.15%, P > 0.05). The incidence of adverse events in skin and subcutaneous tissue was higher in the paroxetine group than in the agomelatine group (none in agomelatine and 4.62% in paroxetine, P = 0.0144).

CONCLUSIONS

Agomelatine showed equivalent antidepressant efficacy to paroxetine in treating MDD patients after 8 weeks of treatment with an acceptable safety.

The impact of severe mental disorders and psychotropic medications on sexual health and its implications for clinical management

Sexual dysfunction often accompanies severe psychiatric illness and can be due to both the mental disorder itself and the use of psychotropic treatments. Many sexual symptoms resolve as the mental state improves, but treatment-related sexual adverse events tend to persist over time, and are unfortunately under-recognized by clinicians and scarcely investigated in clinical trials. Treatment-emergent sexual dysfunction adversely affects quality of life and may contribute to reduce treatment adherence. There are important differences between the various compounds in the incidence of adverse sexual effects, associated with differences in mechanisms of action. Antidepressants with a predominantly serotonergic activity, antipsychotics likely to induce hyperprolactinaemia, and mood stabilizers with hormonal effects are often linked to moderate or severe sexual dysfunction, including decreased libido, delayed orgasm, anorgasmia, and sexual arousal difficulties. Severe mental disorders can interfere with sexual function and satisfaction, while patients wish to preserve a previously satisfactory sexual activity. In many patients, a lack of intimate relationships and chronic deterioration in mental and physical health can be accompanied by either a poor sexual life or a more frequent risky sexual behaviour than in the general population. Here we describe the influence of psychosis and antipsychotic medications, of depression and antidepressant drugs, and of bipolar disorder and mood stabilizers on sexual health, and the optimal management of patients with severe psychiatric illness and sexual dysfunction.

Drug information update: agomelatine

Agomelatine is a new antidepressant, licensed for the treatment of unipolar major depression, with a mode of action that combines activation of melatonin receptors with blockade of 5-HT2C receptors. Agomelatine is notable for its short duration of action in the body and modest side-effect burden; however, a number of theoretical and practical challenges have limited its adoption into mainstream treatment in the UK. Current meta-analyses show marginal clinical benefits of agomelatine relative to placebo and an association with occasional increases in liver transaminases. Theoretically it is not clear whether agomelatine does block brain 5-HT2C receptors in humans at therapeutic doses and the optimum daily timing of administration in depression has not been clearly established. However, agomelatine's novel mode of action justifies further study, perhaps with the eventual aim of matching its use in depression to patients with specific disturbances in circadian rhythm.

Agomelatine for the Treatment of Major Depressive Episodes in Schizophrenia-Spectrum Disorders: An Open-Prospective Proof-of-Concept Study

BACKGROUND

Depressive episodes in schizophrenia constitute a major clinical problem, and treatment success is often limited by treatment-emergent side effects. Agomelatine, an agonist at melatonergic MT1/MT2 receptors and 5-HT2C receptor antagonist, is a new antidepressant with a novel mode of action which constitutes a potential therapeutic option for depression in schizophrenia.

METHODS

Twenty-seven patients with lifetime diagnoses within the schizophrenia spectrum and comorbid depression were treated with agomelatine in addition to stable doses of antipsychotic agents. Severity of depression and other psychopathological domains (positive/negative symptoms, general psychopathology, psychosocial performance) was assessed regularly by means of standardized rating scales during a 6-week acute treatment phase as well as after a 6-week extension phase. Moreover, safety measures (electrocardiograms, laboratory counts, neurological and non-neurological side effects, sleep quality, sexual functioning) were monitored on a regular basis.

RESULTS

Depressive symptoms improved significantly during the 6-week acute treatment phase. In parallel, a significant improvement of negative symptoms, global psychopathology, and psychosocial performance was observed, whereas positive symptoms remained stable. Agomelatine was mostly well tolerated with predominantly mild and self-limiting side effects. However, pharmacokinetic interactions with antipsychotic agents were observed. Interestingly, the quality of sleep did not improve significantly, pointing toward mechanisms that do not depend on resynchronization of circadian rhythms.

CONCLUSIONS

Agomelatine appears to be safe and efficacious in treating depressive symptoms in patients with schizophrenia. The risk of pharmacokinetic interactions with antipsychotic agents warrants the need of therapeutic drug monitoring, and regular recording of vital signs seems necessary. Further randomized trials will have to confirm these findings.

Studies on the reproductive effects of chronic treatment with agomelatine in the rat

Agomelatine is an antidepressant with a novel mechanism of action. It is a melatonergic agonist for MT1 and MT2 receptors and a serotonin (5-HT2C) receptor antagonist. Agomelatine has been suggested not to have adverse effects on sexual functions. However, the effects of chronic agomelatine administration on reproductive functions have not been sufficiently studied in animal models. We mainly aimed to explore the effects of agomelatine on reproductive functions in the male and female rats. For the experimental studies, Sprague Dawley rats were used. The animals started to receive daily oral agomelatine (10mg/kg) on post-natal day 21. Agomelatine advanced vaginal opening in the female rats whereas it delayed puberty onset in the male rats. Agomelatine treatment significantly decreased intromission frequencies, which indicates a facilitator role of this antidepressant on male sexual behavior. In the forced swimming test (FST) used for assessing antidepressant efficacy, agomelatine induced a significant decrease in duration of immobility, and an increase in the swimming time, respectively, which confirms the antidepressant-like activity of agomelatine. The present findings suggest that agomelatine shows a strong antidepressant effect in the male rats without any adverse influences on sexual behavior, and its effects on pubertal maturation seem to show sex-dependent differences.

Psychiatric disorders and sexual dysfunction

Sexual problems are highly prevalent among patients with psychiatric disorders. They may be caused by the psychopathology of the psychiatric disorder but also by its pharmacotherapy. Both positive symptoms (e.g., psychosis, hallucinations) as well as negative symptoms (e.g., anhedonia) of schizophrenia may negatively interfere with interpersonal and sexual relationships. Atypical antipsychotics have fewer sexual side-effects than the classic antipsychotics. Mood disorders may affect libido, sexual arousal, orgasm, and erectile function. With the exception of bupropion, agomelatine, mirtazapine, vortioxetine, amineptine, and moclobemide, all antidepressants cause sexual side-effects. Selective serotonin reuptake inhibitors (SSRIs) may particularly delay ejaculation and female orgasm, but also can cause decreased libido and erectile difficulties. SSRI-induced sexual side-effects are dose-dependent and reversible. Very rarely, their sexual side-effects persist after SSRI discontinuation. This is often preceded by genital anesthesia. Some personality characteristics are a risk factor for sexual dysfunction. Also patients with eating disorders may suffer from sexual difficulties. So far, research into psychotropic-induced sexual side-effects suffers from substantial methodologic limitations. Patients tend not to talk with their clinician about their sexual life. Psychiatrists and other doctors need to take the initiative to talk about the patient's sexual life in order to become informed about potential medication-induced sexual difficulties.

[Evidence-based choice and antidepressants treatment in psychiatry]

Depression is a severe and usually recurrent mental disorder which leads to a prominent impairment of physical and social functioning, a reduced quality of life of the patients, implies as well an increased morbidity and mortality. Reducing the social-economic depression burden is possible in the optimization of decision-making process of antidepressant choice (including SSRIs and SNRIs) based on the evidence-based risk/benefit ratio and resource saving potential treatment involving target psychosocial interventions and monitoring of long-term treatment adherence.

Antidepressant efficacy of agomelatine: meta-analysis of published and unpublished studies

OBJECTIVE

To systematically review published and unpublished efficacy studies of agomelatine in people with depression.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Literature search (Pubmed, Embase, Medline), Cochrane Central Register of Controlled Trials, European Medicines Agency (EMA) regulatory file for agomelatine, manufacturers of agomelatine (Servier).

ELIGIBILITY CRITERIA

Double blind randomised placebo and comparator controlled trials of agomelatine in depression with standard depression rating scales.

DATA SYNTHESIS

Studies were pooled by using a random effects model with DerSimonian and Laird weights for comparisons with placebo and comparator antidepressant. The primary efficacy measure (change in rating scale score) was summarised with standardised mean difference (SMD; a measure of effect size) and secondary outcome measures with relative risks. All results were presented with 95% confidence intervals. Statistical heterogeneity was explored by visual inspection of funnel plots and by the I(2) statistic. Moderators of effect were explored by meta-regression.

RESULTS

We identified 20 trials with 7460 participants meeting inclusion criteria (11 in the published literature, four from the European Medicines Agency file, and five from the manufacturer). Almost all studies used the 17 item Hamilton depression rating scale (score 0-50). Agomelatine was significantly more effective than placebo with an effect size (SMD) of 0.24 (95% confidence interval 0.12 to 0.35) and relative risk of response 1.25 (1.11 to 1.4). Compared with other antidepressants, agomelatine showed equal efficacy (SMD 0.00, -0.09 to 0.10). Significant heterogeneity was uncovered in most analyses, though risk of bias was low. Published studies were more likely than unpublished studies to have results that suggested advantages for agomelatine.

CONCLUSIONS

Agomelatine is an effective antidepressant with similar efficacy to standard antidepressants. Published trials generally had more favourable results than unpublished studies.

Efficacy and tolerability of agomelatine in the treatment of depression

Depression is a severe and usually recurrent mental disorder which often leads to a significant impairment of everyday functioning, a reduced quality of life, and also great suffering of the patients. The treatment of a depressive disorder is not only limited to acute treatment; it also requires prolonged management. Patient compliance is of utmost importance. Unpleasant adverse effects and their impact on everyday living often lead to a premature discontinuation of antidepressant treatment and result in an unfavorable treatment outcome. The new antidepressant agomelatine, a melatonergic MT1/MT2 agonist and 5-HT2C receptor antagonist, has exhibited good antidepressant efficacy in acute, short-term, and long-term treatment. The adverse effect profile of agomelatine has been proven to be favorable and comparable to placebo, which is very important for good treatment compliance and adherence.

Antidepressant-induced sexual dysfunction in men

Most of the available antidepressant medications, including tricyclic antidepressants, monoamine oxidase inhibitors, selective serotonin reuptake inhibitors, and dual noradrenergic/serotonergic reuptake inhibitors have been reported to be associated with sexual dysfunction in both sexes. This manuscript reviews evidence concerning the relative incidence of treatment emergent sexual dysfunction in men being treated with antidepressant drugs. Both double-blind controlled trials and large clinical series report a high incidence of sexual dysfunction, especially ejaculatory delay, with serotonergic drugs. The incidence of sexual dysfunction in men appears to be much lower with drugs whose primary mechanism of action involves adrenergic or dopaminergic systems.

Saffron for treatment of fluoxetine-induced sexual dysfunction in women: randomized double-blind placebo-controlled study

OBJECTIVE

Saffron (Crocus sativus L.) has shown beneficial aphrodisiac effects in some animal and human studies. The aim of the present study was to assess the safety and efficacy of saffron on selective serotonin reuptake inhibitor-induced sexual dysfunction in women.

METHODS

This was a randomized double-blind placebo-controlled study. Thirty-eight women with major depression who were stabilized on fluoxetine 40 mg/day for a minimum of 6 weeks and had experienced subjective feeling of sexual dysfunction entered the study. The patients were randomly assigned to saffron (30 mg/daily) or placebo for 4 weeks. Measurement was performed at baseline, week 2, and week 4 using the Female Sexual Function Index (FSFI). Side effects were systematically recorded.

RESULTS

Thirty-four women had at least one post-baseline measurement and completed the study. Two-factor repeated measure analysis of variance showed significant effect of time × treatment interaction [Greenhouse-Geisser's corrected: F(1.580, 50.567) = 5.366, p = 0.012] and treatment for FSFI total score [F(1, 32) = 4.243, p = 0.048]. At the end of the fourth week, patients in the saffron group had experienced significantly more improvement in total FSFI (p < 0.001), arousal (p = 0.028), lubrication (p = 0.035), and pain (p = 0.016) domains of FSFI but not in desire (p = 0.196), satisfaction (p = 0.206), and orgasm (p = 0.354) domains. Frequency of side effects was similar between the two groups.

CONCLUSIONS

It seems saffron may safely and effectively improve some of the fluoxetine-induced sexual problems including arousal, lubrication, and pain.

Adjunctive agomelatine therapy in the treatment of acute bipolar II depression: a preliminary open label study

PURPOSE

The circadian rhythm hypothesis of bipolar disorder (BD) suggests a role for melatonin in regulating mood, thus extending the interest toward the melatonergic antidepressant agomelatine as well as type I (acute) or II cases of bipolar depression.

PATIENTS AND METHODS

Twenty-eight depressed BD-II patients received open label agomelatine (25 mg/bedtime) for 6 consecutive weeks as an adjunct to treatment with lithium or valproate, followed by an optional treatment extension of 30 weeks. Measures included the Hamilton depression scale, Pittsburgh Sleep Quality Index, the Clinical Global Impression Scale-Bipolar Version, Young Mania Rating Scale, and body mass index.

RESULTS

Intent to treat analysis results demonstrated that 18 of the 28 subjects (64%) showed medication response after 6 weeks (primary study endpoint), while 24 of the 28 subjects (86%) responded by 36 weeks. When examining primary mood stabilizer treatment, 12 of the 17 (70.6%) valproate and six of the 11 (54.5%) lithium patients responded by the first endpoint. At 36 weeks, 14 valproate treated (82.4%) and 10 lithium treated (90.9%) subjects responded. At 36 weeks, there was a slight yet statistically significant (P = 0.001) reduction in body mass index and Pittsburgh Sleep Quality Index scores compared to respective baseline values, regardless of mood stabilizer/outcome. Treatment related drop-out cases included four patients (14.28%) at week 6 two valproate-treated subjects with pseudo-vertigo and drug-induced hypomania, respectively, and two lithium-treated subjects with insomnia and mania, respectively. Week 36 drop outs were two hypomanic cases, one per group.

CONCLUSION

Agomelatine 25 mg/day was an effective and well-tolerated adjunct to valproate/lithium for acute depression in BD-II, suggesting the need for confirmation by future double blind, controlled clinical trials.