Clinical evidence for serotonin and norepinephrine reuptake inhibition of duloxetine

Duloxetine reduces opioid consumption and pain after total hip or knee arthroplasty: a meta-analysis of randomized controlled trials

PURPOSE

There is no consensus in the current literature on the analgesic role of duloxetine after total hip arthroplasty (THA) or total knee arthroplasty (TKA). Thus, we designed this meta-analysis to reveal the analgesic effectiveness and safety of duloxetine in TKA or THA.

METHODS

As of October 2022, two authors (L.C. and W.Q.J.) independently searched five main databases (EMBASE, Web of Science, PubMed, Cochrane Library, and Google Scholar) to find relevant studies. Duloxetine vs. placebo in randomized controlled trials (RCTs) for THA or TKA were included. We set perioperative total opioid consumption as the primary outcome. Secondary outcomes included resting or dynamic pain scores over time, gastrointestinal adverse events, neurological adverse events, and other adverse reactions.

RESULTS

Eight RCTs with 695 patients were incorporated in our study. This meta-analysis showed high evidence that duloxetine was effective in reducing perioperative opioid consumption (Standard mean difference [SMD] = - 0.50, 95% confidence intervals [CI]: -0.70 to - 0.31, P < 0.00001) and low to moderate evidence that duloxetine could reduce pain within three weeks after surgery. Low to high evidence showed no differences between the two groups for most adverse events. Substantial evidence suggests that duloxetine can reduce nausea and vomiting after surgery (Risk ratio [RR] = 0.69, 95% CI: 0.50 to 0.95, P = 0.02, I2 = 4%). However, moderate evidence suggested that duloxetine might be associated with increased postoperative drowsiness (RR = 1.83, 95% CI: 1.08 to 3.09, P = 0.02, I2 = 0%).

CONCLUSION

Duloxetine reduced overall opioid consumption in the perioperative period and relieved pain within three weeks after surgery without increasing the risk of adverse drug events. Duloxetine can be part of a multimodal management regimen in patients with THA and TKA.

A multicenter, randomized, double-blind, duloxetine-controlled, non-inferiority trial of desvenlafaxine succinate extended-release in patients with major depressive disorder

BACKGROUND

Desvenlafaxine and duloxetine are selective serotonin and norepinephrine reuptake inhibitors. Their efficacy has not been directly compared using statistical hypotheses. This study evaluated the non-inferiority of desvenlafaxine extended-release (XL) to duloxetine in patients with major depressive disorder (MDD).

METHODS

In this study, 420 adult patients with moderate-to-severe MDD were enrolled and randomly assigned (1:1) to receive 50 mg (once daily [QD]) of desvenlafaxine XL (n = 212) or 60 mg QD of duloxetine (n = 208). The primary endpoint was evaluated using a non-inferiority comparison based on the change from baseline to 8 weeks in the 17-item Hamilton Depression Rating Scale (HAMD₁₇) total score. Secondary endpoints and safety were evaluated.

RESULTS

Least-squares mean change in HAM-D₁₇ total score from baseline to 8 weeks was -15.3 (95% confidence interval [CI]: -17.73, -12.89) in the desvenlafaxine XL group and - 15.9 (95% CI, -18.44, -13.39) in the duloxetine group. The least-squares mean difference was 0.6 (95% CI: -0.48, 1.69), and the upper boundary of 95% CI was less than the non-inferiority margin (2.2). No significant between-treatment differences were found in most secondary efficacy endpoints. The incidence of the most common treatment-emergent adverse events (TEAEs) was lower for desvenlafaxine XL than for duloxetine for nausea (27.2% versus 48.8%) and dizziness (18.0% versus 28.8%).

LIMITATIONS

A short-term non-inferiority study without a placebo arm.

CONCLUSIONS

This study demonstrated that desvenlafaxine XL 50 mg QD was non-inferior to duloxetine 60 mg QD in efficacy in patients with MDD. Desvenlafaxine had a lower incidence of TEAEs than duloxetine did.

Metabolomics analysis of plasma samples of patients with fibromyalgia and electromagnetic sensitivity using GC-MS technique

Fibromyalgia (FM) is a chronic and systemic condition that causes widespread chronic pain, asthenia, and muscle stiffness, as well as in some cases depression, anxiety, and disorders of the autonomic system. The exact causes that lead to the development of FM are still unknown today. In a percentage of individuals, the symptoms of FM are often triggered and/or exacerbated by proximity to electrical and electromagnetic devices. Plasma metabolomic profile of 54 patients with fibromyalgia and self-reported electromagnetic sensitivity (IEI-EMF) were compared to 23 healthy subjects using gas chromatography-mass spectrometry (GC-MS) coupled with multivariate statistical analysis techniques. Before the GC-MS analysis the plasma samples were extracted with a modified Folch method and then derivatized with methoxamine hydrochloride in pyridine solution and N-trimethylsilyltrifuoroacetamide. The combined analysis allowed to identify a metabolomic profile able of distinguishing IEI-EMF patients and healthy subjects. IEI-EMF patients were therefore characterized by the alteration of 19 metabolites involved in different metabolic pathways such as energy metabolism, muscle, and pathways related to oxidative stress defense and chronic pain. The results obtained in this study complete the metabolomic "picture" previously investigated on the same cohort of IEI-EMF patients with ¹H-NMR spectroscopy, placing a further piece for better understanding the pathophysiological mechanisms in patients with IEI-EMF.

Analgesic effect of nobiletin against neuropathic pain induced by the chronic constriction injury of the sciatic nerve in mice

Neuropathic pain is chronic pain resulting from central or peripheral nerve damage that remains difficult to treat. Current evidence suggests that nobiletin, isolated from Citrus reticulata Blanco, possesses analgesic and neuroprotective effects. However, its effect on neuropathic pain has not been reported. This study evaluated the analgesic effect of nobiletin on neuropathic pain induced by chronic constriction injury (CCI) in mice. In vivo, mice were intragastrically administered with nobiletin (30, 60, 120 mg/kg) for eight consecutive days, respectively. Our study indicated that nobiletin ameliorated mechanical allodynia, cold allodynia and thermal hyperalgesia on CCI mice at doses that do not induce significant sedation. Moreover, nobiletin could ameliorate axonal and myelin injury of the sciatic nerve and further restore abnormal sciatic nerve electrical activity on CCI mice. In vitro studies indicated that nobiletin could suppress the proteins and mRNA expression of the IRF5/P2X4R/BDNF signalling pathway in fibronectin-induced BV2 cells. Overall, our results indicated that nobiletin might exert an analgesic effect on CCI-induced neuropathic pain in mice by inhibiting the IRF5/P2X4R/BDNF signalling pathway in spinal microglia. This study provided a novel potential therapeutic drug for neuropathic pain and new insights into the pharmacological action of nobiletin.

Noise Induced Depression-Like Behavior, Neuroinflammation and Synaptic Plasticity Impairments: The Protective Effects of Luteolin

Noise is a kind of sound that causes agitation and harms human health. Studies have shown that noise can lead to neuroinflammation, damage to synaptic plasticity and altered levels of neurotransmitters that may result in depression. The present study demonstrated that luteolin exerted antidepressant-like effects by improving neuroinflammation in a mouse model of noise-induced depression. Luteolin significantly alleviated noise-induced depression-like behavior. Notably, luteolin treatment not only remarkably ameliorated noise-induced inflammation in the hippocampus and prefrontal cortex, but also increased synapsin. Furthermore, luteolin treatment significantly increased the contents of serum 5-hydroxytryptamine and norepinephrine in noise-induced mice. In sum, luteolin exerts antidepressant effects indepression-like mice caused by noise, which can serve as a potential agent for the treatment of chronic noise-induced depression.

Application of PLGA nanoparticles to enhance the action of duloxetine on microglia in neuropathic pain

Duloxetine (DLX) is a selective serotonin and noradrenaline reuptake inhibitor (SNRI) used for the treatment of pain, but it has been reported to show side effects in 10-20% of patients. Its analgesic efficacy in central pain is putatively related to its influence on descending inhibitory neuronal pathways. However, DLX can also affect the activation of microglia. This study was performed to investigate whether PLGA nanoparticles (NPs), which are expected to enhance targeting to microglia, can improve the analgesic efficacy and limit the side effects of DLX. PLGA NPs encapsulating a low dose of DLX (DLX NPs) were synthesized and characterized and their localization was determined. The analgesic and anti-inflammatory effects of DLX NPs were evaluated in a spinal nerve ligation (SNL)-induced neuropathic pain model. The analgesic effect of DLX lasted for only a few hours and disappeared within 1 day. However, DLX NPs alleviated mechanical allodynia, and the effect was maintained for 1 week. DLX NPs were localized to the spinal microglia and suppressed microglial activation, phosphorylation of p38/NF-κB-mediated pathways and the production of inflammatory cytokines in the spinal dorsal horn of SNL rats. We demonstrated that DLX NPs can provide a prolonged analgesic effect by enhanced targeting of microglia. Our observations imply that DLX delivery through nanoparticle encapsulation allows drug repositioning with a prolonged analgesic effect, and reduces the potential side effects of abuse and overdose.

Effects of alkaloids on peripheral neuropathic pain: a review

Neuropathic pain is a debilitating pathological pain condition with a great therapeutic challenge in clinical practice. Currently used analgesics produce deleterious side effects. Therefore, it is necessary to investigate alternative medicines for neuropathic pain. Chinese herbal medicines have been widely used in treating intractable pain. Compelling evidence revealed that the bioactive alkaloids of Chinese herbal medicines stand out in developing novel drugs for neuropathic pain due to multiple targets and satisfactory efficacy. In this review, we summarize the recent progress in the research of analgesic effects of 20 alkaloids components for peripheral neuropathic pain and highlight the potential underlying molecular mechanisms. We also point out the opportunities and challenges of the current studies and shed light on further in-depth pharmacological and toxicological studies of these bioactive alkaloids. In conclusion, the alkaloids hold broad prospects and have the potentials to be novel drugs for treating neuropathic pain. This review provides a theoretical basis for further applying some alkaloids in clinical trials and developing new drugs of neuropathic pain.

Expert Opinion on the Extensive Use of Prescription Crystalline Glucosamine Sulfate in the Multimodal Treatment of Osteoarthritis in Ukraine, Kazakhstan, Uzbekistan, and Armenia

Objective:

The present work was led by a multidisciplinary panel of experts and proposes an extensive review on the use of prescription crystalline glucosamine sulfate (pCGS) in the multimodal treatment of osteoarthritis (OA) applicable in Ukraine and other Commonwealth of Independent States (CIS) countries.

Methods:

A panel of rheumatologists, orthopedic surgeons, and field experts from Ukraine and CIS regions discussed the management of OA. Literature was systematically searched using Medline, EMBASE, CIHNAL, and Cochrane Library databases. The 2-day meeting critically reviewed the available literature, treatment algorithms, pharmacoeconomic aspects, and real-world instances to form a multimodal approach based both on real-life clinical practice and systematic literature research for the management of OA in Ukraine and CIS countries.

Expert Opinion:

pCGS plays a pivotal role in the stepwise approach to OA treatment. If it is necessary (step 1), the combined use of pCGS with paracetamol and topical nonsteroidal anti-inflammatory drugs (NSAIDs) has been recommended. If symptoms persist, oral NSAIDs and intra-articular (IA) hyaluronic acid or corticosteroids are added to the therapy (step 2) of pCGS in the patients. In case of insufficient relief and severe OA (step 3), pCGS along with oral NSAIDs, IA corticosteroids, and duloxetine have been recommended. Patient stratification with regular monitoring and careful alterations in treatment were advocated.

Conclusions:

This expert opinion article recommends a modified approach to the existing guidelines incorporating pCGS in treatment modality of OA in Ukraine and CIS countries. Extensive use of pCGS targets early symptomatic relief in OA while limiting the adverse effects due to long-term use of analgesics and NSAIDs.

Managing fibromyalgia syndrome in pregnancy no bridges between USA and EU

The first aim of this article is to analyze the risk/benefit ratio of using psychotropic drugs approved in some countries for treating fibromyalgia syndrome (FMS) during pregnancy. Assessing the effectiveness of non-pharmacological interventions is the second scope of this article, in order to help clinicians to manage FMS in pregnancy in those countries were no drugs are approved for treating the disease. Following the PRISMA guidelines for systematic reviews, a literature search was conducted on PubMed and Google Scholar. Separate literature searches were performed for the three psychotropic drugs approved in the USA for treating FMS, psychotherapy, and transcranial magnetic stimulation (TMS). Perinatal duloxetine exposure is associated with increased risk of gestational and perinatal complications. With regards pregabalin, available information suggests that the drug is not devoid of structural teratogenicity potential. No data are available for milnacipran. Duloxetine and pregabalin should be only given to pregnant women diagnosed with severe forms of FMS after carefully weighing the benefits and risks for the mother-fetus dyad. On the other hand, we have to consider that the proportion of women who discontinue psychotropic drugs during pregnancy is as high as 85.4%. This figure raises further questions about adequate alternative treatment of FMS during the perinatal period. Moreover, neither duloxetine nor milnacipran or pregabalin have been approved by the EMEA for the treatment of FMS. Unfortunately, psychological treatment of FMS in perinatal women are not yet tested and data on TMS are conflicting.

Efficacy and tolerability of pharmacotherapy for post-stroke depression: a network meta-analysis

Background

Post-stroke depression (PSD) occurs in approximately one third of stroke survivors, leading to great disability and mortality. As there is no consensus on the optimal pharmacological treatment for PSD, we aimed to evaluate the relative efficacy and tolerability of the available pharmacological interventions.

Materials and Methods

We did a network meta-analysis to incorporate evidence from relevant trials providing direct and indirect comparisons. We searched PubMed, the Cochrane Library Central Register of Controlled Trials, Embase and the reference lists of relevant articles up to March, 2017 for randomized controlled trials (RCTs), for different pharmacotherapies of PSD. For efficacy analysis, the primary outcome was the mean change in Hamilton Depression Scale (HAMD) score between baseline and endpoint. For tolerability analysis, the outcome was presented by the discontinuation for any reason. This study is registered with PROSPERO, number CRD42016049049.

Results

From a total of 869 citations, 15 RCTs with 876 participants were included. 13 drugs were considered. For efficacy, paroxetine ranked the best for HAMD reduction, followed by imipramine, reboxetine, nortriptyline, citalopram and fluoxetine at the end of treatment. However, duloxetine ranked the best at 4-week and 8-week duration for HAMD reduction. For tolerability, paroxetine ranked the best but there is no significant result between any comparisons.

Conclusions

Paroxetine is probably the best option to consider for patients with PSD. To get a quicker relief of depression, duloxetine might be useful for its rapid onset of antidepressant action. The tolerability was comparable among all the antidepressants. But more high-quality RCTs are needed.

Evaluation of the benefits of exercise on cognition in major depressive disorder

BACKGROUND

Cognitive impairment is increasingly recognized as a significant symptom in patients with major depressive disorder (MDD). While exercise is already recommended in many treatment guidelines for patients with MDD and has been shown to improve cognition in other disorders (e.g., Alzheimer's, Parkinson's, schizophrenia), limited research is available evaluating the effect of exercise on cognition in MDD.

METHODS

We provide a narrative review of existing literature regarding the effect(s) of exercise on cognition across several neurodegenerative and psychiatric diseases, and particularly in MDD, with specific emphasis on study design and methodology that may impair adequate synthesis of the results. We also describe mechanisms by which exercise may improve cognition in depression and other brain disorders.

RESULTS

Of existing studies with MDD, data are equivocal, as some are supportive of improved cognition, whereas others demonstrate no benefit. Several limitations were noted, including insufficiently-powered designs, variability in interventions examined (e.g., aerobic, anaerobic, mind-body) or control groups, lack of attention to the status of baseline cognitive impairment, and/or heterogeneity across outcome measures and clinical characteristics.

CONCLUSIONS

While preliminary results suggest the potential for exercise as a beneficial treatment or augmentation strategy for impaired cognition in MDD, the aforementioned limitations necessitate further investigation.

Duloxetine in treating generalized anxiety disorder in adults: A meta-analysis of published randomized, double-blind, placebo-controlled trials

INTRODUCTION

We carried out a meta-analysis of published randomized, double-blind, placebo-controlled trails to assess the efficacy and tolerability of duloxetine in treating generalized anxiety disorder (GAD).

METHODS

A literature search was conducted using PubMed, ISI Web of Science, Medline, Cochrane Central Register of Controlled Trials databases until October 2014. The search terms used were "anxiety or anxious or generalized anxiety disorder" and "duloxetine or Cymbalta." Meta-analysis was conducted using Revman 5.1. A fixed-effects model was carried out on the response rates, remission rates, and symptom improvement. Risk ratio (RR) and mean difference (MD) were calculated. The overall effect size was calculated with 95% confidence intervals (CIs).

RESULTS

Seven studies (n = 2,674) were found eligible for inclusion in analysis. Six studies provided data on response, which showed a significant difference between duloxetine and placebo (n = 1,975, RR = 1.48, 95% CI, 1.34-1.63). Remission rates revealed significant superiority of duloxetine (n = 2,399, RR = 1.60, 95% CI, 1.43-1.80). Change from baseline scores on Hamilton Rating Scale for Anxiety showed a reduction in anxiety symptoms to be significantly efficient for duloxetine (n = 1,135, MD = 3.34, 95% CI, 2.37-4.32). Duloxetine increased statistically Sheehan Disability Scale total score (n = 1,652, MD = 2.84, 95% CI, 2.08-3.60). The discontinuation of the duloxetine was not significantly different from that of the placebo.

CONCLUSION

Duloxetine is moderately effective in treating GAD with improvement in overall function and well tolerability.

Cognition in major depressive disorder: a 'Systemically Important Functional Index' (SIFI)

PURPOSE OF REVIEW

Cognitive dysfunction in major depressive disorder (MDD) is common, pervasive across multiple subdomains of cognitive function, and is a principle determinant of health outcomes from patient, provider, and societal perspectives. The overarching aim herein is to provide rationale for the evaluation, measurement, and specific treatment of cognitive function in adults with MDD.

RECENT FINDINGS

Evidence indicates that cognitive dysfunction in MDD is a critical mediator of workplace disability. Systematic evaluation and measurement of cognitive function is warranted. All individuals with MDD should be evaluated for both objective and subjective cognitive dysfunction. Although differences between antidepressants in overall antidepressant efficacy are not consistent, unequivocal differences in improving measures of cognitive function are noted with evidence indicating that vortioxetine has multidomain cognitive benefits, whereas duloxetine has replicated evidence of improving measures of acquisition and recall (i.e. memory).

SUMMARY

The probability of functional recovery in MDD is likely to increase with interventions that specifically target and improve measures of cognitive function. Clinicians are encouraged to evaluate patients using a validated measure (e.g. the THINC-it tool); prevention of cognitive impairment in MDD is a critical therapeutic priority. Vortioxetine and duloxetine benefit measures of cognitive function in MDD. Preliminary evidence of beneficial effects on cognitive emotional processing are reported with ketamine.

BDNF plasma levels variations in major depressed patients receiving duloxetine

It has been frequently reported that brain-derived neurotrophic factor (BDNF) plays an important role in the pathophysiology of major depressive disorder (MDD). Objective of the study was to investigate BDNF levels variations in MDD patients during antidepressant treatment with duloxetine. 30 MDD patients and 32 healthy controls were assessed using Hamilton Depression Scale (HAM-D) and monitored for BDNF plasma levels at baseline, week 6 and week 12 of duloxetine treatment (60 mg/day) and at baseline, respectively. According to early clinical response to duloxetine (defined at week 6 by reduction >50 % of baseline HAM-D score), MDD patients were distinguished in early responders (ER) and early non-responders (ENR), who reached clinical response at week 12. Laboratory analysis showed significant lower baseline BDNF levels among patients compared to controls. During duloxetine treatment, in ENR BDNF levels increased, reaching values not significantly different compared to controls, while in ER BDNF levels remained nearly unchanged. Lower baseline BDNF levels observed in patients possibly confirm an impairment of the NEI stress-adaptation system and neuroplasticity in depression, while BDNF increase and normalization observed only in ENR might suggest differential neurobiological backgrounds in ER vs. ENR within the depressive syndrome.

Occupancy of serotonin transporter by tramadol: a positron emission tomography study with [11C]DASB

Tramadol is used for the treatment of pain, and it is generally believed to activate the μ-opioid receptor and inhibit serotonin (5-HT) and norepinephrine (NE) transporters. Recent findings from animal experiments suggest that 5-HT reuptake inhibition in brain is related to pain reduction. However, there has been no report of 5-HT transporter (5-HTT) occupancy by tramadol at clinical doses in humans. In the present study, we investigated 5-HTT occupancy by tramadol in five subjects receiving various doses of tramadol by using positron emission tomography (PET) scanning with the radioligand [11C]DASB. Our data showed that mean 5-HTT occupancies in the thalamus by single doses of tramadol were 34.7% at 50 mg and 50.2% at 100 mg. The estimated median effective dose (ED50) of tramadol was 98.1 mg, and the plasma concentration was 0.33 μg/ml 2 h after its administration; 5-HTT occupancy by tramadol was dose-dependent. We estimated 5-HTT occupancy at 78.7% upon taking an upper limit dose (400 mg) of tramadol. The results of the present study support the finding that 5-HTT inhibition is involved in the mechanism underlying the analgesic effect of tramadol in humans, and a clinical dose of tramadol sufficiently inhibits 5-HTT reuptake; this inhibition is similar to that shown by selective serotonin reuptake inhibitors (SSRIs).

Effects of duloxetine on norepinephrine and serotonin transporter activity in healthy subjects

Duloxetine selectively inhibits the serotonin (5-HT) and norepinephrine (NE) transporters (5-HTT and NET, respectively), as demonstrated in vitro and in preclinical studies; however, transporter inhibition has not been fully assessed in vivo at the approved dose of 60 mg/d. Here, the in vivo effects of dosing with duloxetine 60 mg once daily for 11 days in healthy subjects were assessed in 2 studies: (1) centrally (n = 11), by measuring concentrations of 5-hydroxyindoleacetic acid, 3,4-dihydroxyphenylglycol (DHPG), and NE in cerebrospinal fluid, and (2) versus escitalopram 20 mg/d (n = 32) in a 2-period crossover study by assessing the ΔDHPG/ΔNE ratio in plasma during orthostatic testing and by pharmacokinetic/pharmacodynamic modeling of reuptake inhibition using subjects' serum in cell lines expressing cloned human 5-HTT or NET. At steady state, duloxetine significantly reduced concentrations of DHPG and 5-hydroxyindoleacetic acid (P < 0.05), but not NE, in cerebrospinal fluid; DHPG was also decreased in plasma and urine. The ΔDHPG/ΔNE ratio in plasma decreased significantly more with duloxetine than escitalopram (65% and 21%, respectively; P < 0.0001). Ex vivo reuptake inhibition of 5-HTT was comparable (EC50 = 44.5 nM) for duloxetine and escitalopram, but duloxetine inhibited NET more potently (EC50 = 116 nM and 1044 nM, respectively). Maximal predicted reuptake inhibition for 5-HTT was 84% for duloxetine and 80% for escitalopram, and that for NET was 67% and 14%, respectively. In summary, duloxetine significantly affected 5-HT and NE turnover in the central nervous system and periphery; these effects presumably occurred via inhibition of reuptake by the 5-HTT and NET, as indicated by effects on functional reuptake inhibition ex vivo.

Does duloxetine improve cognitive function independently of its antidepressant effect in patients with major depressive disorder and subjective reports of cognitive dysfunction?

Introduction. Cognitive deficits are commonly reported by patients with major depressive disorder (MDD). Duloxetine, a dual serotonin/noradrenaline reuptake inhibitor, may improve cognitive deficits in MDD. It is unclear if cognitive improvements occur independently of antidepressant effects with standard antidepressant medications. Methods. Thirty participants with MDD who endorsed cognitive deficits at screening received 12-week duloxetine treatment. Twenty-one participants completed treatment and baseline and posttreatment cognitive testing. The Cambridge Neuropsychological Test Automated Battery was used to assess the following cognitive domains: attention, visual memory, executive function/set shifting and working memory, executive function/spatial planning, decision making and response control, and verbal learning and memory. Results. Completers showed significant cognitive improvements across several domains on tasks assessing psychomotor function and mental processing speed, with additional improvements in visual and verbal learning and memory, and affective decision making and response control. Overall significance tests for executive function tasks were also significant, although individual tasks were not, perhaps due to the small sample size. Most notably, cognitive improvements were observed independently of symptom reduction on all domains except verbal learning and memory. Conclusions. Patients reporting baseline cognitive deficits achieved cognitive improvements with duloxetine treatment, most of which were independent of symptomatic improvement. This trial is registered with NCT00933439.

VEGF plasma level variations in duloxetine-treated patients with major depression

BACKGROUND

The vascular endothelial growth factor (VEGF) signaling, which modulates angiogenesis and neurogenesis within the neurovascular unit, might play an important role in the neuro-endocrine-immune (NEI) stress-adaptation system. Recent evidence suggests that VEGF is involved in the pathophysiology of a number of diseases including major depressive disorder (MDD) and is affected by some treatments, including antidepressants. The objective of the study was to investigate the VEGF level variations in MDD patients during antidepressant treatment with duloxetine, a relatively new SNRI.

METHODS

A total of 30 MDD patients and 32 healthy controls were assessed using the Hamilton Depression Scale (HAM-D) and monitored for VEGF plasma levels at baseline, week 6 and week 12 of duloxetine treatment (60 mg/day) and at baseline, respectively.

RESULTS

According to early clinical response to duloxetine (defined at week 6 by reduction>50% of baseline HAM-D score), the MDD patients were divided into early responders (ER) and early non-responders (ENR). During duloxetine treatment, we found an opposite trend in the VEGF levels between ER and ENR: in ER the VEGF levels significantly increased in association with clinical response at W6, while in ENR the VEGF levels significantly decreased in association with an overall clinical response at W12.

LIMITATIONS

Small sample size.

CONCLUSIONS

The opposite trends in VEGF levels, increasing in ER and decreasing in ENR, might reflect differential Norepinephrine/Serotonin effects of duloxetine on differential neurobiological backgrounds of depressive syndromes. Overall, the modulation of VEGF signaling within the neurovascular unit during antidepressant treatment could hypothetically favor the remodeling of neural circuitry, contributing to adaptive adjustment of the NEI stress-adaptation system.

Relative contributions of norepinephrine and serotonin transporters to antinociceptive synergy between monoamine reuptake inhibitors and morphine in the rat formalin model

Multimodal analgesia is designed to optimize pain relief by coadministering drugs with distinct mechanisms of action or by combining multiple pharmacologies within a single molecule. In clinical settings, combinations of monoamine reuptake inhibitors and opioid receptor agonists have been explored and one currently available analgesic, tapentadol, functions as both a µ-opioid receptor agonist and a norepinephrine transporter inhibitor. However, it is unclear whether the combination of selective norepinephrine reuptake inhibition and µ-receptor agonism achieves an optimal antinociceptive synergy. In this study, we assessed the pharmacodynamic interactions between morphine and monoamine reuptake inhibitors that possess different affinities and selectivities for norepinephrine and serotonin transporters. Using the rat formalin model, in conjunction with measurements of ex vivo transporter occupancy, we show that neither the norepinephrine-selective inhibitor, esreboxetine, nor the serotonin-selective reuptake inhibitor, fluoxetine, produce antinociceptive synergy with morphine. Atomoxetine, a monoamine reuptake inhibitor that achieves higher levels of norepinephrine than serotonin transporter occupancy, exhibited robust antinociceptive synergy with morphine. Similarly, a fixed-dose combination of esreboxetine and fluoxetine which achieves comparable levels of transporter occupancy potentiated the antinociceptive response to morphine. By contrast, duloxetine, a monoamine reuptake inhibitor that achieves higher serotonin than norepinephrine transporter occupancy, failed to potentiate the antinociceptive response to morphine. However, when duloxetine was coadministered with the 5-HT₃ receptor antagonist, ondansetron, potentiation of the antinociceptive response to morphine was revealed. These results support the notion that inhibition of both serotonin and norepinephrine transporters is required for monoamine reuptake inhibitor and opioid-mediated antinociceptive synergy; yet, excess serotonin, acting via 5-HT₃ receptors, may reduce the potential for synergistic interactions. Thus, in the rat formalin model, the balance between norepinephrine and serotonin transporter inhibition influences the degree of antinociceptive synergy observed between monoamine reuptake inhibitors and morphine.

Evaluation of the effects of duloxetine and escitalopram on 24-hour heart rate variability: a mechanistic study using heart rate variability as a pharmacodynamic measure

A decrease in heart rate variability (HRV) can indicate increased sympathetic nervous system activity and possibly increased norepinephrine levels. In this randomized, placebo- and escitalopram (ESC)-controlled, subject-blind, 2-period, crossover study, 26 healthy subjects 50 to 65 years old received duloxetine (DLX) 60 mg once daily or ESC 20 mg once daily for 11 days, each in sequential study periods separated by a 10-day or more washout period. Continuous electrocardiogram recordings were obtained by Holter monitoring (baseline, day 9, and day 10 of treatment). Duloxetine and ESC did not produce any clinically significant effects on standard measures of HRV, which included SD of normal R-R intervals and the root mean square difference among successive R-R normal intervals index values, mean change in SD of normal R-R intervals, and frequency domain analysis. However, treatment with DLX was associated with significantly less change from baseline in total beats per 24 hours than ESC, which was an unexpected finding compared with previous observations in which vital signs were measured at a specific time point while awake. In conclusion, in healthy adults exposed to DLX or ESC, no clinically significant effects on HRV were observed.

Might different cytokine trends in depressed patients receiving duloxetine indicate differential biological backgrounds

BACKGROUND

Correlational studies investigating neurohormonal-cytokine modulation by antidepressants suggest, among others, variations in cytokines balances as state markers of different biological subtypes of major depressive disorder (MDD) and response predictors to specific treatments. Objective of the study was to investigate cytokines modulation by duloxetine, a relatively newer SNRI with "clean" dual serotonin/norepinephrine mechanism.

METHODS

30 MDD patients and 32 healthy controls were assessed using Hamilton Depression Scale (HAM-D) and monitored for levels of IL-1β, IL-2, IL-4, IL-10, IL-12, IFN-γ and TNF-α, at baseline, week 6 and week 12 of duloxetine treatment (60mg/day) and at baseline, respectively.

RESULTS

Early responders (ER: defined at week 6 by reduction >50% of baseline HAM-D score) and early non-responders (ENR) showed opposite trends in cytokine levels during duloxetine treatment: ENR were characterized by baseline Th2 shift compared to controls (lower IL-1β, IFN-γ and TNF-α) with increase in Th1 cytokines levels during treatment (increase of IL-1β, IL-12, IFN-γ, IL-1β/IL-10 and TNF-α/IL-10, decrease of IL-10), achieving clinical response at week 12; ER were characterized by baseline Th2-to-Th1 relative switch compared to ENR (higher IL-1β, IL-1β/IL-10 and TNF-α/IL-10) with reduction in Th1 cytokines levels during treatment (decrease of TNF-α and TNF-α/IL-10), achieving clinical response at week 6.

LIMITATIONS

Small sample size.

CONCLUSIONS

In accordance to early clinical response, duloxetine treatment could divide depressed patients into at least 2 subgroups characterized by clinical and laboratory differentiated behavior, suggesting different neurobiological background within depressive syndrome differentially sensitive to different drug components: pro-serotonergic effect and increase in Th1 cytokines in ENR vs. pro-noradrenergic effect and decrease in Th1 cytokines in ER.

Efficacy and safety of duloxetine 60 mg once daily in major depressive disorder: a review with expert commentary

OBJECTIVE

Major depressive disorder (MDD) is a significant public health concern and challenges health care providers to intervene with appropriate treatment. This article provides an overview of efficacy and safety information for duloxetine 60 mg/day in the treatment of MDD, including its effect on painful physical symptoms (PPS).

DESIGN

A literature search was conducted for articles and pooled analyses reporting information regarding the use of duloxetine 60 mg/day in placebo-controlled trials.

SETTING

Placebo-controlled, active-comparator, short- and long-term studies were reviewed.

PARTICIPANTS

Adult (≥18 years) patients with MDD.

MEASUREMENTS

Effect sizes for continuous outcome (change from baseline to endpoint) and categorical outcome (response and remission rates) were calculated using the primary measures of 17-item Hamilton Rating Scale for Depression (HAMD-17) or Montgomery-Åsberg Depression Rating Scale (MADRS) total score. The Brief Pain Inventory and Visual Analogue Scales were used to assess improvements in PPS. Glass estimation method was used to calculate effect sizes, and numbers needed to treat (NNT) were calculated based on HAMD-17 and MADRS total scores for remission and response rates. Safety data were examined via the incidence of treatment-emergent adverse events and by mean changes in vital-sign measures.

RESULTS

Treatment with duloxetine was associated with small-to-moderate effect sizes in the range of 0.12 to 0.72 for response rate and 0.07 to 0.65 for remission rate. NNTs were in the range of 3 to 16 for response and 3 to 29 for remission. Statistically significant improvements (p≤0.05) were observed in duloxetine-treated patients compared to placebo-treated patients in PPS and quality of life. The safety profile of the 60-mg dose was consistent with duloxetine labeling, with the most commonly observed significant adverse events being nausea, dry mouth, diarrhea, dizziness, constipation, fatigue, and decreased appetite.

CONCLUSION

These results reinforce the efficacy and tolerability of duloxetine 60 mg/day as an effective short- and long-term treatment for adults with MDD. The evidence of the independent analgesic effect of duloxetine 60 mg/day supports its use as a treatment for patients with PPS associated with depression. This review is limited by the fact that it included randomized clinical trials with different study designs. Furthermore, data from randomized controlled trials may not generalize well to real clinical practice.

Adverse reactions to duloxetine in depression

INTRODUCTION

Untreated or inadequately treated depression is the largest risk factor for suicide. However, treatment with different antidepressants can have considerable adverse effects, including the increase of the frequency of suicidal thoughts and behavior. This review summarizes the frequency and severity of adverse events observed during the treatment of depression with duloxetine and considers their relevance to clinical practice.

AREAS COVERED

A comprehensive review of the literature was conducted using PubMed and Medline databases listing data published until December 2010. Articles describing safety and tolerability of duloxetine were selected and reference lists of these articles were scrutinized for further relevant papers. In addition, US and EU Summaries of Product Characteristics were studied.

EXPERT OPINION

Treatment with duloxetine was associated with mild to moderate adverse events; sexual dysfunction, nausea, headache, dry mouth, somnolence and dizziness being the most frequent among them. No increase in death from suicide and suicidal thoughts and behavior were detected as compared to placebo. So as to avoid discontinuation syndrome as a consequence of abrupt withdrawal of duloxetine, 2 weeks tapering has been recommended before discontinuation. Overall, duloxetine was found to be well tolerated and can be safely administered even in older patients and in those with concomitant illnesses.

Increase in IL-6 levels among major depressive disorder patients after a 6-week treatment with duloxetine 60 mg/day: a preliminary observation

BACKGROUND

Immune modifications, including changes in interleukin (IL)-6 levels, have often been observed in major depressive disorder (MDD) during treatment with selective serotonin reuptake inhibitors (SSRIs) or the serotonin norepinephrine reuptake inhibitor (SNRI) venlafaxine. Nevertheless, no equivalent observation for the SNRI duloxetine has been made to date.

METHOD

Sixteen patients diagnosed with MDD and an actual major depressive episode according to DSM-IV criteria and 16 healthy controls entered a 6-week trial with duloxetine 60 mg/day. All subjects (n = 32) were assessed using the Hamilton Depression Rating Scale (HAM-D), the Young Mania Rating Scale (YMRS), and were monitored for IL-6 levels both at baseline and at week 6. Blood samples for IL-6 levels were evaluated by ELISA.

RESULTS

After 6 weeks of treatment, the mean total scores for HAM-D declined both in the depressed and control groups, while IL-6 modification showed an opposite trend both in depressed (12.38 ± 19.80 to 19.73 ± 18.94 pg/mL) and control subjects (12.25 ± 21.12 to 17.63 ± 20.44 pg/mL), as did YMRS (ns), although none of the subjects switched to (hypo)mania. Of note, IL-6 levels increased significantly only in the responders subgroup (n = 9; P = 0.012).

CONCLUSION

The small sample size and weak design of this study limit the validity of our results, which should be regarded as preliminary only. Nonetheless, the trend of increasing IL-6 levels observed in responder patients treated with duloxetine should prompt further controlled, extended studies with larger samples, with the specific aim of better assessing a putative differential role of norepinephrinergic antidepressant stimulation of serotonergic reuptake inhibition in determining modifications in IL-6 levels. Ideally, more accurate replication studies may contribute to further understanding of the complex interaction of mood, antidepressant response, and the immune system.

Duloxetine in the treatment of chronic pain due to fibromyalgia and diabetic neuropathy

Duloxetine is a serotonin-norepinephrine reuptake inhibitor approved by the US Food and Drug Administration for the treatment of fibromyalgia and painful diabetic neuropathy at doses of 60 mg daily. Duloxetine has been shown to significantly improve the symptoms of chronic pain associated with these disorders, as measured by the Fibromyalgia Impact Questionnaire, Brief Pain Inventory scores, the Clinical Global Impressions Scale, and other various outcome measures in several placebo-controlled, randomized, double-blind, multicenter studies. Symptom improvement generally began within the first few weeks, and continued for the duration of the study. In addition, the efficacy of duloxetine was found to be due to direct effects on pain symptoms rather than secondary to improvements in depression or anxiety. Adverse events including nausea, constipation, dry mouth, and insomnia, were mild and transient and occurred at relatively low rates. In conclusion, duloxetine, a selective inhibitor for the serotonin and norepinephrine transporters, is efficacious in the treatment of chronic pain associated with fibromyalgia or diabetic neuropathy, and has a predictable tolerability profile, with adverse events generally being mild to moderate.

Effects of duloxetine treatment on brain response to painful stimulation in major depressive disorder

Major depressive disorder (MDD) is characterized by a constellation of affective, cognitive, and somatic symptoms associated with functional abnormalities in relevant brain systems. Painful stimuli are primarily stressful and can trigger consistent responses in brain regions highly overlapping with the regions altered in MDD patients. Duloxetine has proven to be effective in treating both core emotional symptoms and somatic complaints in depression. This study aimed to assess the effects of duloxetine treatment on brain response to painful stimulation in MDD patients. A total of 13 patients and a reference group of 20 healthy subjects were assessed on three occasions (baseline, treatment week 1, and week 8) with functional magnetic resonance imaging (fMRI) during local application of painful heat stimulation. Treatment with duloxetine was associated with a significant reduction in brain responses to painful stimulation in MDD patients in regions generally showing abnormally enhanced activation at baseline. Clinical improvement was associated with pain-related activation reductions in the pregenual anterior cingulate cortex, right prefrontal cortex, and pons. Pontine changes were specifically related to clinical remission. Increased baseline activations in the right prefrontal cortex and reduced deactivations in the subgenual anterior cingulate cortex predicted treatment responders at week 8. This is the first fMRI study addressed to assess the effect of duloxetine in MDD. As a novel approach, the application of painful stimulation as a basic neural stressor proved to be effective in mapping brain response changes associated with antidepressant treatment and brain correlates of symptom improvement in regions of special relevance to MDD pathophysiology.

Fibromyalgia: diagnosis and treatment options

BACKGROUND

Fibromyalgia is a widespread, chronic pain disorder that includes a complex constellation of somatic and emotional symptoms. Controlled clinical trials for both medication and nonmedication therapies have led to sound, evidence-based recommendations for the care of patients with fibromyalgia.

OBJECTIVE

This review article was designed to provide updated information from database literature searches on fibromyalgia epidemiology, including gender differences, psychological comorbidity, and treatment with medication and nonmedication therapies.

METHODS

A literature review was performed by identifying fibromyalgia articles published in English from January 2000 to October 2008 using the PubMed and EMBASE databases. Search terms included fibromyalgia, exercise, gender, nonpharmacologic, placebo-controlled, randomized, and treatment.

RESULTS

New epidemiologic data support important differences in fibromyalgia symptom severity between the sexes and the important role of comorbid psychological distress. Physicians diagnose fibromyalgia in women at an approximately 3- to 6-fold rate compared with men. Well-conducted clinical trials and recently published treatment guidelines reinforce effective treatment with medication and nonpharmacologic therapy. The strongest evidence suggests effective treatment of fibromyalgia with duloxetine and milnacipran. Studies also report efficacy with gabapentin, pramipexole, pregabalin, tramadol, and IV tropisetron. Nonpharmacologic treatments should include fitness and strengthening exercise, as well as warm-water therapy and psychological pain management techniques.

CONCLUSIONS

Fibromyalgia is a common, disabling, chronic pain condition that predominantly affects women. Symptoms can be effectively treated using both drug and nondrug therapies. In general, treatment benefits in fibromyalgia appear largely independent of patient sex.

Duloxetine for the treatment of fibromyalgia

This article presents a brief review of the physiologic abnormalities seen in fibromyalgia, current theories of widespread pain, and treatment options, including emerging therapeutics, with a focus on the use of duloxetine to manage fibromyalgia symptoms. Major clinical trials that examine the efficacy and effectiveness of duloxetine to date are reviewed, and safety issues are discussed.

Duloxetine: in patients with fibromyalgia

Duloxetine is a selective serotonin and norepinephrine reuptake inhibitor available in delayed-release capsules for oral use. Duloxetine 60 mg/day, compared with placebo, was associated with a greater reduction from baseline in the Brief Pain Inventory (BPI) average pain severity score, a greater improvement in the patient-rated global impression of improvement (PGI-I) scale in patients with fibromyalgia, with or without major depressive disorder, in two 12- and 15-week phase III studies. In a 27-week, phase III trial, there was no significant difference between duloxetine (60 or 120 mg/day) and placebo for the least squares mean change from baseline to endpoint in BPI average pain scores and the PGI-I score. The significant improvements in efficacy that occurred in patients with fibromyalgia during 8 weeks of open-label treatment with duloxetine 60 mg/day were generally maintained during 52 weeks of subsequent blinded treatment at the same dosage in a phase III trial. Nonresponders during treatment with open-label duloxetine 60 mg/day, demonstrated no increased ability to respond if the duloxetine dosage was up-titrated to 120 mg/day than those who remained on the same dosage during the subsequent 52-week, double-blind phase. Duloxetine was generally well tolerated in studies of up to 1 year in duration, with nausea being the most frequent adverse event and main cause for discontinuing therapy.

Inhibition of serotonin and norepinephrine reuptake and inhibition of phosphodiesterase by multi-target inhibitors as potential agents for depression

Compounds possessing more than one functional activity incorporated into the same molecule may have advantages in treating complex disease states. Balanced serotonin/norepinephrine reuptake inhibitors (SNRIs) (i.e., (R)- and (S)-norduloxetine) were chemically linked to a PDE4 inhibitor via a five carbon bridge. The new dual SNRI/PDE4 inhibitors (i.e., (R)-15 and (S)-15) showed moderately potent serotonin reuptake inhibition (IC(50) values of 442 and 404 nM, respectively) but low reuptake inhibition of norepinephrine (IC(50) values of 2097 and 2190 nM, respectively) in vitro. The dual SNRI/PDE4 inhibitors (i.e., (R)-15 and (S)-15) also inhibited PDE4D2 (i.e., K(i) values of 23 and 45 nM, respectively). Due to their synergistic functional activity, SNRI/PDE4 inhibitors may be effective in treating diseases such as depression.

Duloxetine: a review of its use in the treatment of generalized anxiety disorder

Duloxetine (Cymbalta(R)) is a potent serotonin and noradrenaline (norepinephrine) reuptake inhibitor (SNRI) in the CNS. It is indicated for the treatment of generalized anxiety disorder (GAD) as well as other indications. In patients with GAD of at least moderate severity, oral duloxetine 60-120 mg once daily was effective with regard to improvement from baseline in assessments of anxiety and functional impairment, and numerous other clinical endpoints. Longer-term duloxetine 60-120 mg once daily also demonstrated efficacy in preventing or delaying relapse in responders among patients with GAD. In addition, duloxetine was generally well tolerated, with most adverse events being of mild to moderate severity in patients with GAD in short- and longer-term trials. Additional comparative and pharmacoeconomic studies are required to position duloxetine among other selective serotonin reuptake inhibitors and SNRIs. However, available clinical data, and current treatment guidelines, indicate that duloxetine is an effective first-line treatment option for the management of GAD. Duloxetine is a potent and selective inhibitor of serotonin and noradrenaline transporters, and a weak inhibitor of dopamine transporters. It has a low affinity for neuronal receptors, such as alpha(1)- and alpha(2)-adrenergic, dopamine D(2), histamine H(1), muscarinic, opioid and serotonin receptors, as well as ion channel binding sites and other neurotransmitter transporters, such as choline and GABA transporters. It does not inhibit monoamine oxidase types A or B. The pharmacokinetics of duloxetine in healthy volunteers were dose proportional over the range of 40-120 mg once daily. Steady state was typically reached by day 3 of administration. Duloxetine may be administered without regard to food or time of day. Duloxetine is highly protein bound and is widely distributed throughout tissues. It is rapidly and extensively metabolized in the liver by cytochrome P450 (CYP) 1A2 and 2D6, and its numerous metabolites, which are inactive, are mainly excreted in the urine. The mean elimination half-life of duloxetine is approximately 12 hours. Duloxetine is a substrate for CYP1A2 and CYP2D6 and a moderate inhibitor of CYP2D6. Concomitant use of duloxetine and potent CYP1A2 inhibitors should be avoided and duloxetine should be used with caution in patients receiving drugs that are extensively metabolized by CYP2D6, particularly those with a narrow therapeutic index. Duloxetine was effective in the short-term treatment of patients with primary GAD of at least moderate severity. In four randomized, double-blind, placebo-controlled, multicentre, phase III trials, duloxetine 60-120 mg once daily for 9 or 10 weeks was significantly more effective than placebo with regard to the primary endpoint of mean change in Hamilton Anxiety Rating Scale (HAM-A) total score from baseline to study endpoint. In addition, all other endpoints were generally improved from baseline to a greater extent with duloxetine 60-120 mg once daily than with placebo. Duloxetine also improved patient role functioning (assessed using Sheehan Disability Scale global impairment functioning scores), health-related quality of life and patient well-being compared with placebo. Duloxetine was effective in patients with GAD who were aged >/=65 years. Pooled results of data from the two short-term efficacy trials that also included an active comparator arm showed that the mean change in HAM-A scores with duloxetine relative to placebo were of the same magnitude as those with venlafaxine extended release versus placebo. Duloxetine 60-120 mg once daily was also more effective than placebo in preventing or delaying relapse in responders to duloxetine in a longer-term study. In this study, patients with GAD received duloxetine during a 26-week, open-label, acute treatment phase and responders were then randomized to continue on duloxetine or receive placebo during a 26-week, double-blind, continuation phase. Time to relapse was significantly longer in duloxetine recipients than in placebo recipients. In addition, significantly fewer duloxetine recipients than placebo recipients relapsed during the double-blind phase of the trial and more duloxetine recipients achieved remission. Short- (9-10 weeks) and longer-term (52 weeks) treatment with duloxetine 60-120 mg once daily was generally well tolerated in patients with GAD, with the majority of adverse events being of mild to moderate severity. Nausea, dry mouth, headache, constipation, dizziness and fatigue were among the most common treatment-emergent adverse events. The adverse event profile of duloxetine did not differ with dose or treatment duration. Significantly more patients receiving short-term duloxetine than placebo discontinued treatment because of an adverse event, with nausea being the only event that resulted in significantly more treatment discontinuations in duloxetine recipients than in placebo recipients. Serious adverse events were uncommon with both short- and longer-term duloxetine treatment. Two episodes of attempted suicide and one episode of completed suicide occurred in duloxetine recipients during the 24-week open-label phase of a longer-term trial. No deaths or suicides were reported in any of the short-term trials. Discontinuation-emergent adverse events, most commonly nausea and dizziness, occurred in up to one-third of duloxetine recipients in the short-term trials.

Open-label support for duloxetine for the treatment of panic disorder

Panic disorder with or without agoraphobia is a common, often chronic and refractory anxiety disorder. Although a number of pharmacotherapies are now indicated for panic disorder, many patients do not respond to available interventions. We hypothesized that duloxetine, a serotonin-norepinephrine reuptake inhibitor (SNRI) that has greater initial noradrenergic effects than venlafaxine, would have broad efficacy for individuals with panic disorder. Fifteen individuals with panic disorder with or without agoraphobia received 8 weeks of open label duloxetine flexibly dosed from 60 to 120 mg per day. Duloxetine treatment resulted in significant anxiolysis as measured by the primary outcome measure, the Panic Disorder Severity Scale (PDSS) (paired t(df) = 4.02(14), P= 0.0013), as well as measures of generalized anxiety, depression and quality of life (all P < 0.05). Although definitive conclusions are limited due to its small open-label nature, this first prospective study provides preliminary support for the efficacy of duloxetine for panic disorder and suggests larger randomized controlled study is warranted.