Preclinical discovery of duloxetine for the treatment of depression

Introduction: Affective disorders, including major depressive disorder (MDD), are among the most severely disabling mental disorders, and in many cases areIntroduction: Affective disorders, including major depressive disorder (MDD), are among the most severely disabling mental disorders, and in many cases are associated with poor treatment outcomes. From the emergence of the monoamine hypothesis of depression, the first-line treatment for MDD had mainly acted by inhibiting monoamine reuptake, and thereby increasing these levels in the synaptic cleft. However, in recent years, several newantidepressant drugs have appeared, including duloxetine, a dual serotonin (5-HT) and noradrenaline (NA) reuptake inhibitor recommended for the treatment of MDD. Areas covered: The article reviews and discusses the biochemical and functional profile of duloxetine splitting the review into acute and long-term treatment with this dual monoamine reuptake inhibitor. In addition, the authors summarize available preclinical behavioral research data, which have demonstrated among other effects, the antidepressant-like activity of duloxetine in several animal models. The authors focus on the most recent literature on synaptic neuroplasticity modulation of this antidepressant drug. Finally, the authors briefly mention other approved indications of duloxetine. Expert opinion: Duloxetine inhibits 5-HT and NA reuptake, effectively desensitizes various autoreceptors and promotes neuroplasticity. Clinically, duloxetine is an effective antidepressant that is well tolerated and has significant efficacy in the treatment of MDD. associated with poor treatment outcomes. From the emergence of the monoamine hypothesis of depression, the first-line treatment for MDD had mainly acted by inhibiting monoamine reuptake, and thereby increasing these levels in the synaptic cleft. However, in recent years, several new antidepressant drugs have appeared, including duloxetine, a dual serotonin (5-HT) and noradrenaline (NA) reuptake inhibitor recommended for the treatment of MDD

Serotonin and Noradrenaline Reuptake Inhibitors Improve Micturition Control in Mice

Poor micturition control may cause profound distress, because proper voiding is mandatory for an active social life. Micturition results from the subtle interplay of central and peripheral components. It involves the coordination of autonomic and neuromuscular activity at the brainstem level, under the executive control of the prefrontal cortex. We tested the hypothe- sis that administration of molecules acting as reuptake inhibitors of serotonin, noradrenaline or both may exert a strong effect on the control of urine release, in a mouse model of overac- tive bladder. Mice were injected with cyclophosphamide (40 mg/kg), to increase micturition acts. Mice were then given one of four molecules: the serotonin reuptake inhibitor imipra- mine, its metabolite desipramine that acts on noradrenaline reuptake, the serotonin and nor- adrenaline reuptake inhibitor duloxetine or its active metabolite 4-hydroxy-duloxetine. Cyclophosphamide increased urine release without inducing overt toxicity or inflammation, except for increase in urothelium thickness. All the antidepressants were able to decrease the cyclophosphamide effects, as apparent from longer latency to the first micturition act, decreased number of urine spots and volume of released urine. These results suggest that serotonin and noradrenaline reuptake inhibitors exert a strong and effective modulatory ef- fect on the control of urine release and prompt to additional studies on their central effects on brain areas involved in the social and behavioral control of micturition

Duloxetine alleviates high light-induced anxiety-related behaviors in Wistar rats

Purpose: To investigate the effect of subchronic duloxetine treatment on high light-induced anxietyrelated behaviors in Wistar rats. Methods: Adult male Wistar rats (n = 30) were randomly assigned to three groups of rats (10 rats/group): control group, 30 mg/kg duloxetine group, and 60 mg/kg duloxetine group. Intraperitoneal injection of duloxetine was given once a day for ten days. The anxiolytic effect of duloxetine in the rats was assessed using light/dark box (LDB) anxiety test. Results: Anxiety-related behaviors were significantly reduced in duloxetine-treated rats, when compared with control group. The reductions were not dose-dependent (light zone time and latency time were significantly increased, while dark zone time decreased significantly, p < 0.05). The number of rearings significantly increased in 30 mg/kg duloxetine group, relative to control and 60 mg/kg duloxetine groups (p < 0.05). However, there were no significant differences in the number of light-todark entrances among the groups (p > 0.05). Conclusion: These results show that subchronic treatment with duloxetine alleviates anxiety-related behaviors in Wistar rats

Predictors of Treatment with Duloxetine or Venlafaxine XR among Adult Patients Treated for Depression in Primary Care Practices in the United Kingdom

Background. Knowledge about real-world use of duloxetine and venlafaxine XR to treat depression in the UK is limited. Aims. To identify predictors of duloxetine or venlafaxine XR initiation. Method. Adult depressed patients who initiated duloxetine or venlafaxine XR between January 1, 2006 and September 30, 2007 were identified in the UK's General Practice Research Database. Demographic and clinical predictors of treatment initiation with duloxetine and venlafaxine XR were identified using logistic regression. Results. Patients initiating duloxetine (n = 909) were 4 years older than venlafaxine XR recipients (n = 1286). Older age, preexisting unexplained pain, respiratory disease, and pre-period use of anticonvulsants, opioids, and antihyperlipidemics were associated with increased odds of initiating duloxetine compared to venlafaxine XR. Pre-period anxiety disorder was associated with decreased odds of receiving duloxetine. Conclusion. Initial treatment choice with duloxetine versus venlafaxine XR was primarily driven by patient-specific mental and medical health characteristics. General practitioners in the UK favor duloxetine over venlafaxine XR when pain conditions coexist with depression

Management of Widespread Pain and Fibromyalgia

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The facilitatory effect of duloxetine combined with pelvic floor muscle training on the excitability of urethral sphincter motor neurons

Introduction and hypothesis: Aim of this study was to investigate the excitability of sphincter motor neurons under the influence of pelvic floor muscle training (PFMT) and duloxetine. Due to their mechanisms of action, there might be a synergistic effect of duloxetine and PFMT in regard to the facilitation of spinal reflexes controlling urethral sphincter contractions and hence continence. Methods: In ten healthy female subjects, clitoral electric stimulation (CES) and transcranial magnetic stimulation (TMS) were used to determine individual motor thresholds for external urethral sphincter (EUS) contractions before and after PFMT, duloxetine, and PFMT + duloxetine. Results: PFMT and duloxetine alone significantly decreased the motor thresholds for EUS contractions during CES and TMS. However, the combined treatment reduced the motor threshold for EUS contractions significantly stronger compared to PFMT or duloxetine alone. Conclusions: The results are suggestive for a synergistic facilitatory effect of PFMT and duloxetine on sphincter motor neuron activatio

Duloxetine for the management of fibromyalgia syndrome

Fibromyalgia syndrome (FMS) is a widespread pain condition associated with a wide range of additional symptoms including fatigue, insomnia, depression, anxiety and stiffness. Duloxetine is one of three medications currently FDA approved for use in FMS management. Duloxetine is a mixed serotonin and norepinephrine reuptake inhibitor (SNRI) that functions by increasing central nervous system levels of serotonin and norepinephrine. This review is a primer on use of duloxetine in FMS management and includes information on pharmacology and pharmacokinetics, a review of the three duloxetine FMS treatment trials currently in publication, a discussion of the safety and tolerability of duloxetine, and patient-focused perspectives on duloxetine use in FMS management. Duloxetine has proven efficacy in managing pain and mood symptoms in adult FMS patients with and without major depressive disorder. However, due to side effects, duloxetine must be used with caution in patients with fatigue, insomnia, gastrointestinal complaints, headache, cardiovascular disease, bleeding-risk, and in those 24 years of age and younger due to risk of suicidality. Duloxetine use should be avoided in patients with liver disease or alcoholics. As with all medications, duloxetine is best used as part of an individualized regimen that includes nonpharmacologic modalities of exercise, education and behavioral therapies

Cost-effectiveness analysis of pharmaceutical treatment options in the first-line management of major depressive disorder in Belgium

The objective of this study was to assess the cost effectiveness of commonly used antidepressants as first-line treatment of major depressive disorder (MDD) in Belgium. The model structure was based on a decision tree developed by the Swedish TLV (TandvAyenrds- och lakemedelsformAyennsverket) and adapted to the Belgium healthcare setting, using primary local data on the patterns of treatment and following KCE [Federal Knowledge Center (Federaal Kenniscentrum voor de Gezondheidszorg)] recommendations. Comparators were escitalopram, citalopram, fluoxetine, paroxetine, sertraline, duloxetine, venlafaxine, and mirtazapine. In the model, patients not achieving remission or relapsing after remission on the assessed treatment moved to a second therapeutic step (titration, switch, add-on, or transfer to a specialist). In case of failure in the second step or following a suicide attempt, patients were assumed to be referred to secondary care. The time horizon was 1 year and the analysis was conducted from the National Institute for Health and Disability Insurance (NIHDI; national health insurance) and societal perspectives. Remission rates were obtained from the TLV network meta-analysis and risk of relapse, efficacy following therapeutic change, risk of suicide attempts and related death, utilities, costs (2012), and resources were derived from the published literature and expert opinion. The effect of uncertainty in model parameters was estimated through scenario analyses and a probabilistic sensitivity analysis (PSA). In the base-case analysis, escitalopram was identified as the optimal strategy: it dominated all other treatments except venlafaxine from the NIHDI perspective, against which it was cost effective with an incremental cost-effectiveness ratio of a,not sign6,352 per quality-adjusted life-year (QALY). Escitalopram also dominated all other treatments from the societal perspective. At a threshold of a,not sign30,000 per QALY and from the NIHDI perspective, the PSA showed that the probability of escitalopram being identified as the optimal strategy ranged from 61 % (vs. venlafaxine) to 100 % (vs. fluoxetine). Escitalopram was associated with the highest probability of being the optimal treatment from the NIHDI and societal perspectives. This analysis, based on new Belgian clinical practice data and following KCE requirements, provides additional information that may be used to guide the choice of treatments in the management of MDD in Belgium

The Effect of Duloxetine on Mechanistic Pain Profiles, Cognitive Factors, and Clinical Pain in Patients with Painful Knee Osteoarthritis – A Randomized, Double-Blind, Placebo-Controlled, Crossover Study

BACKGROUND: Duloxetine is indicated in the management of pain in osteoarthritis. Evidence suggests that duloxetine modulates central pain mechanisms and cognitive factors, and these factors are assumed contributing to the analgesic effect. This proof‐of‐mechanism, randomized, placebo‐controlled, crossover, double‐blinded trial evaluated the effect of duloxetine on quantitative sensory testing (QST), cognitive factors and clinical pain in patients with osteoarthritis and to predict the analgesic effect. METHODS: Twenty‐five patients completed this cross‐over study with either 18‐week duloxetine (maximum 60 mg/daily) followed by placebo or vice‐versa. Pressure pain thresholds, temporal summation of pain and conditioned pain modulation were assessed using cuff algometry. The Hospital Anxiety and Depression Scale and the Pain Catastrophizing Scale evaluated cognitive factors. Clinical pain was assessed using Brief Pain Inventory and Western Ontario and McMaster Universities Osteoarthritis Index. Linear regression models were used to predict the analgesic effect of duloxetine. RESULTS: Depending on the clinical pain outcome, 40%–68% of patients were classified as responders to duloxetine. Linear regression models predicted the analgesic effect (predictive value of 45%–75% depending on clinical pain outcome parameter) using a combination of pretreatment QST parameters, cognitive factors and clinical pain. No significant changes were found for QST, cognitive factors or clinical pain on a group level when comparing duloxetine to placebo. CONCLUSION: A combination of pretreatment QST, cognitive factors and clinical pain was able to predict the analgesic response of duloxetine. However, in this relatively small study, duloxetine did not selectively modulate QST, cognitive factors or clinical pain intensity when compared with placebo. SIGNIFICANCE: Duloxetine is proposed as a treatment for chronic pain. Pre‐clinical trials suggest that duloxetine provides analgesia through modulation of descending pain inhibitory pathways or through improvements in cognitive factors. The current study demonstrates that pretreatment mechanistic pain profiling, cognitive factors and clinical pain can predict the analgesic effect of duloxetine and that only a subset of patients might benefit from duloxetine treatment

The facilitatory effect of duloxetine combined with pelvic floor muscle training on the excitability of urethral sphincter motor neurons

INTRODUCTION AND HYPOTHESIS: Aim of this study was to investigate the excitability of sphincter motor neurons under the influence of pelvic floor muscle training (PFMT) and duloxetine. Due to their mechanisms of action, there might be a synergistic effect of duloxetine and PFMT in regard to the facilitation of spinal reflexes controlling urethral sphincter contractions and hence continence. METHODS: In ten healthy female subjects, clitoral electric stimulation (CES) and transcranial magnetic stimulation (TMS) were used to determine individual motor thresholds for external urethral sphincter (EUS) contractions before and after PFMT, duloxetine, and PFMT + duloxetine. RESULTS: PFMT and duloxetine alone significantly decreased the motor thresholds for EUS contractions during CES and TMS. However, the combined treatment reduced the motor threshold for EUS contractions significantly stronger compared to PFMT or duloxetine alone. CONCLUSIONS: The results are suggestive for a synergistic facilitatory effect of PFMT and duloxetine on sphincter motor neuron activation