Clinical outcome and tolerability of duloxetine in the treatment of major depressive disorder: a 12-week study with plasma levels

Baseline depressive symptoms as predictors of efficacy and tolerability of the treatment with duloxetine: a network analysis approach

Introduction

Depression is considered one of the most prevalent and burdensome mental disorders. Only 50-60% of patients respond to first-line treatment. Individuals with depression might benefit from personalized treatment, tailored to the individual needs of the patient. In this study, we aimed to explore the baseline characteristics of depressive symptoms associated with a good response to duloxetine treatment using a network analysis. Additionally, the relationship between baseline psychopathological symptoms and treatment tolerability was assessed.

Methods

The sample of 88 drug-free patients with active depressive episode, who started monotherapy with increasing doses of duloxetine were evaluated. The Hamilton Depression Rating Scale (HAM-D) was used to assess depression severity and the UKU side effect rating scale to monitor adverse drug reactions (ADRs). A network analysis that explored interactions of specific baseline depression symptoms, treatment efficacy and tolerability was performed.

Results

The node representing duloxetine treatment efficacy was directly connected to the nodes representing the first HAM-D item ("depressed mood") (edge weight = 0.191) and duloxetine dose (edge weight = 0.144). The node representing ADRs was directly connected to only one node representing the baseline score of the HAM-D anxiety (psychic) item (edge weight = 0.263).

Discussion

Our findings indicate that individuals with depression presenting greater levels of depressed mood and lower levels of anxiety symptoms might better respond to the treatment with duloxetine in terms of efficacy and tolerability.

Tools for optimising pharmacotherapy in psychiatry (therapeutic drug monitoring, molecular brain imaging and pharmacogenetic tests): focus on antidepressants

Objectives: More than 40 drugs are available to treat affective disorders. Individual selection of the optimal drug and dose is required to attain the highest possible efficacy and acceptable tolerability for every patient.Methods: This review, which includes more than 500 articles selected by 30 experts, combines relevant knowledge on studies investigating the pharmacokinetics, pharmacodynamics and pharmacogenetics of 33 antidepressant drugs and of 4 drugs approved for augmentation in cases of insufficient response to antidepressant monotherapy. Such studies typically measure drug concentrations in blood (i.e. therapeutic drug monitoring) and genotype relevant genetic polymorphisms of enzymes, transporters or receptors involved in drug metabolism or mechanism of action. Imaging studies, primarily positron emission tomography that relates drug concentrations in blood and radioligand binding, are considered to quantify target structure occupancy by the antidepressant drugs in vivo. Results: Evidence is given that in vivo imaging, therapeutic drug monitoring and genotyping and/or phenotyping of drug metabolising enzymes should be an integral part in the development of any new antidepressant drug.Conclusions: To guide antidepressant drug therapy in everyday practice, there are multiple indications such as uncertain adherence, polypharmacy, nonresponse and/or adverse reactions under therapeutically recommended doses, where therapeutic drug monitoring and cytochrome P450 genotyping and/or phenotyping should be applied as valid tools of precision medicine.

A Systematic Review of Efficacy, Safety, and Tolerability of Duloxetine

Duloxetine is a serotonin-norepinephrine reuptake inhibitor approved for the treatment of patients affected by major depressive disorder (MDD), generalized anxiety disorder (GAD), neuropathic pain (NP), fibromyalgia (FMS), and stress incontinence urinary (SUI). These conditions share parallel pathophysiological pathways, and duloxetine treatment might be an effective and safe alternative. Thus, a systematic review was conducted following the 2009 Preferred Reporting Items (PRISMA) recommendations and Joanna Briggs Institute Critical (JBI) Appraisals guidelines. Eighty-five studies focused on efficacy, safety, and tolerability of duloxetine were included in our systematic review. Studies were subdivided by clinical condition and evaluated individually. Thus, 32 studies of MDD, 11 studies of GAD, 19 studies of NP, 9 studies of FMS, and 14 studies of SUI demonstrated that the measured outcomes indicate the suitability of duloxetine in the treatment of these clinical conditions. This systematic review confirms that the dual mechanism of duloxetine benefits the treatment of comorbid clinical conditions, and supports the efficacy, safety, and tolerability of duloxetine in short- and long-term treatments.

Duloxetine plasma level and antidepressant response

BACKGROUND

Major Depressive Disorder (MDD) is associated with a high rate of inadequate treatment response, which is mainly due to the large inter-individual genetic variability in pharmacokinetic and pharmacodynamic targets of antidepressant drugs. Little is still known about the exact association between plasma level of first-line antidepressants and clinical response. This is particularly true for duloxetine, a dual serotonin and norepinephrine reuptake inhibitor recommended as first-line treatment for MDD. The aim of this study was to investigate the association between serum concentration of duloxetine (SCD) and antidepressant response (AR).

METHODS

66 MDD patients treated with duloxetine 60 mg/day monotherapy were recruited in an outpatient setting and followed for three months. Hamilton Depression Rating Scale - 21 (HAMD-21) was administrated at baseline, at month 1, and at month 3 to assess AR. SCD was measured at steady state. Linear regression analysis and nonlinear least-squares regression were used to estimate association between SCD and AR.

RESULTS

SCD showed a high inter-individual variability in our sample, despite the duloxetine fixed oral dosage. We found a strong association between SCD and AR following a bell-shaped function at month 1 and at month 3. Nonetheless, within the recommended SCD range of 30-120 ng/mL a more linear correlation between SCD and AR was observed.

DISCUSSION

Our results suggest that for duloxetine the association between SCD and AR likely follows a bell-shaped quadratic function with poor AR at subtherapeutic SCD and progressive decrease of AR at higher SCD. The maximum antidepressant efficacy seems to require SCD values next to the highest recommended SCD (30-120 ng/mL), probably because of the optimal saturation of both serotonin and norepinephrine transporters. Thus, taking into account the observed high interindividual variability of SCD, our findings suggest that for MDD patients treated with duloxetine, SCD could be a useful tool to guide the treatment by optimizing the oral dosage in order to increase the AR rate.

Duloxetine in elderly major depression disorder: effectiveness and drug plasma level evaluation

OBJECTIVE

The aim of this open-label naturalistic study was to assess clinical outcomes and the predictive value of duloxetine plasma levels in major depressive disorder in the elderly.

METHODS

This naturalistic, open-label design involved 35 outpatients aged between 65 and 87 years. Duloxetine plasma levels were collected in 24 patients after the first month. Patients were evaluated using 21-item Hamilton Rating Scales for Depression, Hamilton Rating Scales for Anxiety, the Clinical Global Impression Severity, Mini Mental State Examination, Cumulative Illness Rating Scale, Barthel Index and Beck's Depression Inventory.

RESULTS

Duloxetine plasma levels at T2 ranged from 4.9 to 201.9 ng/mL without a significant correlation between duloxetine dose and plasma levels. A significant improvement in mean 21-item Hamilton Rating Scales for Depression total scores at T2,T3, T4, T9 and T12 and a progressive significantly decrease of the mean Hamilton Rating Scales for Anxiety scores from T3 to T12 were observed.

CONCLUSIONS

The levels of duloxetine in plasma do not correlate with a greater clinical improvement, indeed appear to adversely affect the improvement of the Beck Depression Inventory and Hamilton Rating Scales for Anxiety. This could be explained by an increase in side effects that may aggravate the discomfort felt by the patient. Copyright © 2016 John Wiley & Sons, Ltd.

Antidepressants but not antipsychotics have antiepileptogenic effects with limited effects on comorbid depressive-like behaviour in the WAG/Rij rat model of absence epilepsy

BACKGROUND AND PURPOSE

Two of the most relevant unmet needs in epilepsy are represented by the development of disease-modifying drugs able to affect epileptogenesis and/or the study of related neuropsychiatric comorbidities. No systematic study has investigated the effects of chronic treatment with antipsychotics or antidepressants on epileptogenesis. However, such drugs are known to influence seizure threshold.

EXPERIMENTAL APPROACH

We evaluated the effects of an early long-term treatment (ELTT; 17 weeks), started before seizure onset (P45), with fluoxetine (selective 5-HT-reuptake inhibitor), duloxetine (dual-acting 5-HT-noradrenaline reuptake inhibitor), haloperidol (typical antipsychotic drug), risperidone and quetiapine (atypical antipsychotic drugs) on the development of absence seizures and comorbid depressive-like behaviour in the WAG/Rij rat model. Furthermore, we studied the effects of these drugs on established absence seizures in adult (6-month-old) rats after a chronic 7 weeks treatment.

KEY RESULTS

ELTT with all antipsychotics did not affect the development of seizures, whereas, both ELTT haloperidol (1 mg · kg(-1) day(-1)) and risperidone (0.5 mg · kg(-1) day(-1)) increased immobility time in the forced swimming test and increased absence seizures only in adult rats (7 weeks treatment). In contrast, both fluoxetine (30 mg · kg(-1) day(-1)) and duloxetine (10-30 mg · kg(-1) day(-1)) exhibited clear antiepileptogenic effects. Duloxetine decreased and fluoxetine increased absence seizures in adult rats. Duloxetine did not affect immobility time; fluoxetine 30 mg · kg(-1) day(-1) reduced immobility time while at 10 mg · kg(-1) day(-1) an increase was observed.

CONCLUSIONS AND IMPLICATIONS

In this animal model, antipsychotics had no antiepileptogenic effects and might worsen depressive-like comorbidity, while antidepressants have potential antiepileptogenic effects even though they have limited effects on comorbid depressive-like behaviour.

Duloxetine: a review of its use in the management of major depressive disorder in older adults

Duloxetine (Cymbalta(®)) is a selective serotonin norepinephrine reuptake inhibitor indicated for the treatment of major depressive disorder (MDD). This article reviews the therapeutic efficacy and tolerability of duloxetine in older adults with MDD and summarizes its pharmacological properties. Treatment with duloxetine significantly improved several measures of cognition, depression, anxiety, pain and health-related quality-of-life (HR-QOL) in older adults with MDD in two 8-week, double-blind, placebo-controlled trials. However, no significant improvements in measures of depression were observed at week 12 (primary endpoint) of a 24-week, double-blind trial, although symptoms of depression did improve significantly at earlier timepoints. Benefit of treatment was also observed during continued therapy in the 24-week study (i.e. after the 12-week primary endpoint) and in an open-label, 52-week study, with improvements being observed in some measures of depression, pain and HR-QOL. Duloxetine was generally well tolerated in these studies, with nausea, dizziness and adverse events reflecting noradrenergic activity (e.g. dry mouth, constipation) being the most common treatment-emergent adverse events during treatment for up to 52 weeks. Duloxetine therapy had little effect on cardiovascular parameters and bodyweight. Although further well designed and long-term studies in this patient population are required to confirm the efficacy of duloxetine and to compare it with that of other antidepressants, current evidence suggests that treatment with duloxetine may be beneficial in older adults with MDD.

Short-term antidepressant administration reduces default mode and task-positive network connectivity in healthy individuals during rest

Resting-state studies in depressed patients have revealed increased connectivity within the default mode network (DMN) and task-positive network (TPN). This has been associated with heightened rumination, which is the tendency to repetitively think about symptoms of distress. Here, we performed a pharmacological neuroimaging study in healthy volunteers to investigate whether short-term antidepressant administration could reduce DMN connectivity. We recorded resting-state functional magnetic resonance imaging (fMRI) scans in twenty-three healthy volunteers after two week intake of the combined serotonin-norepinephrine reuptake inhibitor (SNRI) duloxetine in a double-blind, placebo-controlled, crossover study. Duloxetine improved mood in part as a result of increased resilience to the mood-worsening effects of scanning and reduced DMN and TPN connectivity. Within the DMN, duloxetine reduced connectivity between the medial prefrontal cortex (MPFC) and the lateral parietal cortex (LPC) and uncoupled the MPFC from the dorsolateral prefrontal cortex (DLPFC). Within the TPN, duloxetine uncoupled the intraparietal sulcus (IPS) from the inferior occipital gyrus. These results show that two-week antidepressant administration reduces DMN and TPN connectivity in healthy volunteers, which may contribute to their antidepressant effects in depression.