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

Anxiety disorders, PTSD and OCD: systematic review of approved psychiatric medications (2008-2024) and pipeline phase III medications

Objective

This systematic review examines psychiatric medications approved by the FDA for anxiety disorders, post-traumatic stress disorder (PTSD) and obsessive-compulsive disorder (OCD) from 2008 to 2024 and describes the mechanism of action, indications for both labelled and off-label uses, evidence for efficacy, dosing and adverse effects for each medication.

Methods

The methodology involved a literature search of the PubMed database for studies published from 1 January 2008 to 31 December 2024 on FDA-approved psychiatric medications and phase III pipeline medications, using the keywords: "anxiety" OR "PTSD" OR "OCD" AND "psychopharm*" OR "medic*" OR "pharm*". The authors conducted independent assessments of the resulting articles and reached a consensus on eligible studies to include in this systematic review.

Results

Our review revealed that, in the past 16 years, the FDA approved only two medications for anxiety disorders (a delayed-release form of duloxetine for generalized anxiety disorder and an extended-release form of lorazepam) and none for PTSD or OCD. We also identified 14 pipeline medications for anxiety disorders, eight for PTSD and one for OCD, all of which are currently in phase III clinical trials.

Conclusion

Our results showed a paucity of new medications for anxiety disorders and none for PTSD and OCD in the past 16 years. However, phase III psychiatric medications for anxiety disorders, PTSD and OCD seem to show several agents with novel mechanisms of action, various modes of administration, and improved side-effect profiles.

Perioperative Duloxetine in Total Joint Arthroplasty: An Umbrella Review

PURPOSE

Duloxetine, a serotonin and norepinephrine reuptake inhibitor primarily used for chronic neuropathic pain, has been debated for its efficacy in total joint arthroplasty contexts.

DESIGN

Umbrella review.

METHODS

A comprehensive search spanning PubMed, CINAHL, OVID, Embase, MEDLINE, CENTRAL, Google Scholar, and Cochrane, with no language restrictions up to January 2024, was conducted. Two independent reviewers performed data extraction and quality assessment. Primary outcomes focused on pain scores, with secondary outcomes including morphine consumption.

FINDINGS

This review encompasses 8 randomized controlled trials involving 740 patients and 6 meta-analyses. Moderate-certainty evidence from both individual studies and meta-analyses suggests that duloxetine administration correlates with reduced ambulation (-0.73, 95% confidence interval [CI] -0.95 to -0.51 for central sensitization; -0.36, 95% CI -0.47 to -0.25 for noncentral sensitization) and decreased rest pain scores (-0.81, 95% CI -1.07 to -0.55 for central sensitization; -0.22, 95% CI -0.36 to -0.09 for noncentral sensitization), along with lower morphine consumption (-0.52, 95% CI -0.65 to -0.38). Systematic reviews indicate a consistent trend of duloxetine reducing ambulatory (ranging from -1.45 to 0.13) and resting (ranging from -13.46 to 0.16) pain scores, as well as opioid consumption (ranging from -12.72 to -0.71).

CONCLUSIONS

Despite controversies surrounding its efficacy in total joint arthroplasty, duloxetine demonstrates potential in reducing perioperative pain scores and opioid consumption, even in cases of central sensitization. Further trials with larger cohorts are necessary to strengthen the validity of these findings.

Iodine-catalyzed three-component annulation: access to highly fluorescent trisubstituted thiophenes

An efficient synthesis of highly fluorescent trisubstituted thiophenes was achieved via iodine-catalyzed, base-promoted annulation employing elemental sulfur as a sulfur source. The compounds exhibit excellent photophysical properties like solid-state fluorescence, high quantum yield and solvatochromism. As these thiophene derivatives have potential application in the development of optoelectronic devices, gram-scale synthesis of the desired heterocycles was demonstrated.

Precision Medicine in Antidepressants Treatment

Precision medicine uses innovative approaches to improve disease prevention and treatment outcomes by taking into account people's genetic backgrounds, environments, and lifestyles. Treatment of depression is particularly challenging, given that 30-50% of patients do not respond adequately to antidepressants, while those who respond may experience unpleasant adverse drug reactions (ADRs) that decrease their quality of life and compliance. This chapter aims to present the available scientific data that focus on the impact of genetic variants on the efficacy and toxicity of antidepressants. We compiled data from candidate gene and genome-wide association studies that investigated associations between pharmacodynamic and pharmacokinetic genes and response to antidepressants regarding symptom improvement and ADRs. We also summarized the existing pharmacogenetic-based treatment guidelines for antidepressants, used to guide the selection of the right antidepressant and its dose based on the patient's genetic profile, aiming to achieve maximum efficacy and minimum toxicity. Finally, we reviewed the clinical implementation of pharmacogenomics studies focusing on patients on antidepressants. The available data demonstrate that precision medicine can increase the efficacy of antidepressants and reduce the occurrence of ADRs and ultimately improve patients' quality of life.

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.

Multitargeting the sleep-pain interaction with pharmacological approaches: A narrative review with suggestions on new avenues of investigation

The multimorbidity formed by sleep disturbances and pain conditions is highly prevalent and has a significant impact in global health and in the socioeconomic system. Although different approaches have been directed toward its management, evidence regarding an optimal treatment is lacking, and pharmacological options are often preferred. Health professionals (e.g., pain and sleep clinicians) tend to focus on their respective expertise, targeting a single symptom with a single drug. This may increase polypharmacy and the risk of drug interactions, adverse events, and mortality. Hence, the use of medications that can directly or indirectly improve sleep, pain, and other possible accompanying conditions without exacerbating them becomes especially relevant. The objectives of this comprehensive review are to: a) describe the beneficial or deleterious effects that some commonly used medications to manage pain have on sleep and sleep disorders; and b) describe the beneficial or deleterious effects that frequently prescribed medications for sleep may have on pain. Moreover, medications targeting some specific sleep-pain interactions will be suggested and future directions for improving sleep and alleviating pain of these patients will be provided with clinical and research perspectives.

Duloxetine-Induced Neural Cell Death and Promoted Neurite Outgrowth in N2a Cells

Duloxetine is a clinical drug that is primarily used for treatment of depression and pain, but it has side effects of addiction and tolerance. Cytochrome P450 (CYP) is its metabolic enzyme, and the drug's biofunction results from its neuro-protective effect in animal and cell models. We aimed to investigate the duloxetine-induced neural cytotoxicity effect and its performance in an N2a cell neurite outgrowth model. Cell death was assessed as cell viability using a Cell Count Kit-8 and further evaluated using bright-field images, propidium iodide (PI) and annexin V staining, colony-formation analysis, TUNEL staining of the cells, and biochemical testing. N2a cells were committed to differentiation by serum withdrawal and RA induction, and the neurite outgrowth was evaluated as the number of differentiated cells, longest neurite length, and average neurite length. Cell cycle analysis, PI and annexin V staining, mRNA expression, and biochemical testing were used to evaluate the drug effects on differentiation. The induction of neural cell death by duloxetine was not affected by classic cell death inhibitors but was promoted by the CYP inducer rifampicin. N2a cell neurite outgrowth was promoted by duloxetine via reduction of the CYP2D6 and MDA levels and induction of Bdnf protein levels. Duloxetine induces neural cell death through effects on CYP and promotes N2a cell neurite outgrowth by regulating CYP, Bdnf protein, and the intracellular lipid peroxidation level.

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.

Biocatalysis as Useful Tool in Asymmetric Synthesis: An Assessment of Recently Granted Patents (2014–2019)

The broad interdisciplinary nature of biocatalysis fosters innovation, as different technical fields are interconnected and synergized. A way to depict that innovation is by conducting a survey on patent activities. This paper analyses the intellectual property activities of the last five years (2014–2019) with a specific focus on biocatalysis applied to asymmetric synthesis. Furthermore, to reflect the inventive and innovative steps, only patents that were granted during that period are considered. Patent searches using several keywords (e.g., enzyme names) have been conducted by using several patent engine servers (e.g., Espacenet, SciFinder, Google Patents), with focus on granted patents during the period 2014–2019. Around 200 granted patents have been identified, covering all enzyme types. The inventive pattern focuses on the protection of novel protein sequences, as well as on new substrates. In some other cases, combined processes, multi-step enzymatic reactions, as well as process conditions are the innovative basis. Both industries and academic groups are active in patenting. As a conclusion of this survey, we can assert that biocatalysis is increasingly recognized as a useful tool for asymmetric synthesis and being considered as an innovative option to build IP and protect synthetic routes.

Odorants: a tool to provide nonpharmacological intervention to reduce anxiety during normal and pathological aging

Anxiety disorders represent 1 of the most common classes of psychiatric disorders. In the aging population and for patients with age-related pathology, the percentage of people suffering of anxiety is significantly elevated. Furthermore, anxiety carries with it an increased risk for a variety of age-related medical conditions, including cardiovascular disease, stroke, cognitive decline, and increased severity of motor symptoms in Parkinson's disease. A variety of anxiolytic compounds are available but often carry with them disturbing side effects that impact quality of life. Among nonmedicinal approaches to reducing anxiety, odor diffusion and aromatherapy are the most popular. In this review, we highlight the emerging perspective that the use of odorants may reduce anxiety symptoms or at least potentiate the effect of other anxiolytic approaches and may serve as an alternative form of therapy to deal with anxiety symptoms. Such approaches may be particularly beneficial in aging populations with elevated risk for these disorders. We also discuss potential neural mechanisms underlying the anxiolytic effects of odorants based on work in animal models.

Treatment of Poststroke Pathologic Laughing With Duloxetine: A Case Series

OBJECTIVES

Pathologic laughing is characterized by episodes of uncontrollable laughter caused by underlying neurologic disturbances, such as stroke. Several types of medication, including selective serotonin reuptake inhibitors, have demonstrated only limited success at treating the condition. Duloxetine, a dual serotonin-norepinephrine reuptake inhibitor, is reportedly effective in treating the symptoms of mood disorders. We herein introduce a prospective consecutive sample of stroke patients with pathologic laughing treated with duloxetine.

METHODS

We enrolled patients without a history of psychological illness who exhibited poststroke pathologic laughter. Duloxetine administration was commenced at an initial dose of 30 mg once daily. The dose was increased to 60 mg once daily within 2 weeks for all patients except 2. The effect of the treatment was assessed by means of the Pathological Laughter and Crying Scale.

RESULTS

A total of 7 patients were included in the study. Improvements were observed within an average of 10 days after duloxetine administration. Pathological Laughter and Crying Scale score decreased after duloxetine administration in all patients, and 4 patients demonstrated a decrease in score of more than 50%. All patients reported subjective improvement of symptoms, and no adverse effects were observed.

CONCLUSIONS

This case series demonstrates that duloxetine could attenuate pathologic laughing exhibited by stroke patients; however, further randomized controlled studies are necessary to validate our findings.

Interventional and preventive effects of aripiprazole and ceftriaxone used alone or in combination on oxaliplatin-induced tactile and cold allodynia in mice

BACKGROUND AND PURPOSE

Chemotherapy-induced peripheral neuropathy (CIPN) is a pharmacoresistant neurological complication induced by some antitumor drugs. This study aimed to assess antiallodynic properties of aripiprazole and ceftriaxone used alone or in combination to attenuate neuropathic pain related to CIPN caused by oxaliplatin.

METHODS

Neuropathic pain was induced in mice by a single intraperitoneal dose of oxaliplatin (10 mg/kg). Aripiprazole and ceftriaxone were used in a single- or repeated dosing protocol. Their antiallodynic activity was assessed using von Frey and cold plate tests on the day of oxaliplatin injection and after 7 days. The influence of aripiprazole and ceftriaxone on animals' locomotor activity and motor coordination was also assessed.

RESULTS

Single-dose and repeated-dose aripiprazole 10 mg/kg and ceftriaxone 200 mg/kg used alone and in combination attenuated early-phase and late-phase tactile allodynia in oxaliplatin-treated mice. Repeated administrations of ceftriaxone 200 mg/kg prevented the development of late-phase tactile allodynia. Both drugs showed no antiallodynic properties in the cold plate test. Single-dose aripiprazole 1 and 10 mg/kg but not its repeated administration significantly decreased locomotor activity of oxaliplatin-treated mice. Single-dose aripiprazole 1 and 10 mg/kg, aripiprazole 1 mg/kg + ceftriaxone 50 mg/kg and aripiprazole 1 mg/kg + ceftriaxone 200 mg/kg impaired motor coordination in the rotarod test.

CONCLUSIONS

In mice, neither ceftriaxone nor aripiprazole attenuated cold allodynia. Ceftriaxone alone could attenuate tactile allodynia caused by oxaliplatin without inducing motor adverse effects. Although the administration of aripiprazole reduced tactile allodynia, this effect seems to be limited considering severe motor deficits induced by this drug.

Therapeutic Drug Monitoring of Antidepressants

For a number of antidepressants in current clinical use, concentrations in serum or plasma are a more reliable index of target drug concentrations than is dosage. For such drugs, therapeutic drug monitoring (TDM) may be a useful clinical guide for the purpose of maximizing the likelihood of favorable therapeutic outcome while minimizing the probability of clinical ineffectiveness or adverse side effects. TDM is of greatest benefit when a therapeutic range of serum concentrations has been well established. Even if such a range is not definitively determined, TDM can be of help in situations in which patients are refractory to therapy despite adequate or high dosages, when adverse events supervene even with low doses, or when noncompliance with the intended dosage plan is suspected. Serum antidepressant concentrations from TDM should be interpreted in the full context of the patient's demographic characteristics and clinical status, along with an understanding of the pharmacokinetics of the medication being taken, the timing of the sample in relation to the dosage regimen, and the specific laboratory assay procedure. TDM measurements may be costly, and the potential benefits of the information need to be weighed against the cost to the patient or to the health care system.

Efficacy and tolerability of short-term duloxetine treatment in adults with generalized anxiety disorder: A meta-analysis

OBJECTIVE

To investigate the efficacy and tolerability of duloxetine during short-term treatment in adults with generalized anxiety disorder (GAD).

METHODS

We conducted a comprehensive literature review of the PubMed, Embase, Cochrane Central Register of Controlled Trials, Web of Science, and ClinicalTrials databases for randomized controlled trials(RCTs) comparing duloxetine or duloxetine plus other antipsychotics with placebo for the treatment of GAD in adults. Outcome measures were (1) efficacy, assessed by the Hospital Anxiety and Depression Scale(HADS) anxiety subscale score, the Hamilton Rating Scale for Anxiety(HAM-A) psychic and somatic anxiety factor scores, and response and remission rates based on total scores of HAM-A; (2) tolerability, assessed by discontinuation rate due to adverse events, the incidence of treatment emergent adverse events(TEAEs) and serious adverse events(SAEs). Review Manager 5.3 and Stata Version 12.0 software were used for all statistical analyses.

RESULTS

The meta-analysis included 8 RCTs. Mean changes in the HADS anxiety subscale score [mean difference(MD) = 2.32, 95% confidence interval(CI) 1.77-2.88, P<0.00001] and HAM-A psychic anxiety factor score were significantly greater in patients with GAD that received duloxetine compared to those that received placebo (MD = 2.15, 95%CI 1.61-2.68, P<0.00001). However, there was no difference in mean change in the HAM-A somatic anxiety factor score (MD = 1.13, 95%CI 0.67-1.58, P<0.00001). Discontinuation rate due to AEs in the duloxetine group was significantly higher than the placebo group [odds ratio(OR) = 2.62, 95%CI 1.35-5.06, P = 0.004]. The incidence of any TEAE was significantly increased in patients that received duloxetine (OR = 1.76, 95%CI 1.36-2.28, P<0.0001), but there was no significant difference in the incidence of SAEs (OR = 1.13, 95%CI 0.52-2.47, P = 0.75).

CONCLUSION

Duloxetine resulted in a greater improvement in symptoms of psychic anxiety and similar changes in symptoms of somatic anxiety compared to placebo during short-term treatment in adults with GAD and its tolerability was acceptable.

Impact of duloxetine and dexamethasone for improving postoperative pain after laparoscopic gynecological surgeries: A randomized clinical trial

Background

Patients' surgical experiences are influenced by their perception of pain management. Duloxetine (Dulox) and dexamethasone (Dex) are used in multimodal analgesia to reduce opioid use and side effects. Dulox is a selective serotonin and norepinephrine reuptake inhibitor and has efficacy in chronic pain conditions. Dex enhances postoperative (PO) analgesia and reduces PO nausea and vomiting (PONV).

Methods

Seventy-five female patients were randomly allocated into one of three equal groups. GI received Dulox 60 mg orally and 100 ml 0.9% sodium chloride (normal saline [NS]) intravenous infusion (IVI) over 15 min, GII: received as GI except Dex 0.1 mg/kg was mixed with NS and GIII received identical placebo for Dulox capsule and Dex IVI, 2 h preoperatively. Patients' vitals, visual analog scale (VAS), and sedation score were assessed at 30 min, 1 h, 2 h, 6 h, and 12 h postoperatively. Total pethidine requirements, plasma cortisol, PONV, and patients satisfaction were recorded.

Results

PO time for 1^st rescue analgesic was significantly high in GI and GII compared to GIII and in GII compared to GI. There was a significant less VAS score, heart rate, mean arterial pressure, and a high sedation score in GI and GII compared to GIII at 30 min, 1, 2, and 6 h postoperatively. Total pethidine requirements were significantly less in GI and GII compared to GIII 12 h postoperatively. There was a significant reduction in the 2 h PO serum cortisol (μg/dl) and a significant increase in the PO patients satisfaction score in GI and GII compared to GIII. PONV was decreased significantly in GII compared to GI and GIII.

Conclusion

The use of oral Dulox 60 mg combined with Dex 0.1 mg/kg IVI is more effective than oral Dulox 60 mg alone, 2 h preoperatively, for improving PO pain by reducing the requirements for rescue analgesia and PONV.

A Guide to Medications Inducing Salivary Gland Dysfunction, Xerostomia, and Subjective Sialorrhea: A Systematic Review Sponsored by the World Workshop on Oral Medicine VI

BACKGROUND

Medication-induced salivary gland dysfunction (MISGD), xerostomia (sensation of oral dryness), and subjective sialorrhea cause significant morbidity and impair quality of life. However, no evidence-based lists of the medications that cause these disorders exist.

OBJECTIVE

Our objective was to compile a list of medications affecting salivary gland function and inducing xerostomia or subjective sialorrhea.

DATA SOURCES

Electronic databases were searched for relevant articles published until June 2013. Of 3867 screened records, 269 had an acceptable degree of relevance, quality of methodology, and strength of evidence. We found 56 chemical substances with a higher level of evidence and 50 with a moderate level of evidence of causing the above-mentioned disorders. At the first level of the Anatomical Therapeutic Chemical (ATC) classification system, 9 of 14 anatomical groups were represented, mainly the alimentary, cardiovascular, genitourinary, nervous, and respiratory systems. Management strategies include substitution or discontinuation of medications whenever possible, oral or systemic therapy with sialogogues, administration of saliva substitutes, and use of electro-stimulating devices.

LIMITATIONS

While xerostomia was a commonly reported outcome, objectively measured salivary flow rate was rarely reported. Moreover, xerostomia was mostly assessed as an adverse effect rather than the primary outcome of medication use. This study may not include some medications that could cause xerostomia when administered in conjunction with others or for which xerostomia as an adverse reaction has not been reported in the literature or was not detected in our search.

CONCLUSIONS

We compiled a comprehensive list of medications with documented effects on salivary gland function or symptoms that may assist practitioners in assessing patients who complain of dry mouth while taking medications. The list may also prove useful in helping practitioners anticipate adverse effects and consider alternative medications.

Monoaminergic Mechanisms in Epilepsy May Offer Innovative Therapeutic Opportunity for Monoaminergic Multi-Target Drugs

A large body of experimental and clinical evidence has strongly suggested that monoamines play an important role in regulating epileptogenesis, seizure susceptibility, convulsions, and comorbid psychiatric disorders commonly seen in people with epilepsy (PWE). However, neither the relative significance of individual monoamines nor their interaction has yet been fully clarified due to the complexity of these neurotransmitter systems. In addition, epilepsy is diverse, with many different seizure types and epilepsy syndromes, and the role played by monoamines may vary from one condition to another. In this review, we will focus on the role of serotonin, dopamine, noradrenaline, histamine, and melatonin in epilepsy. Recent experimental, clinical, and genetic evidence will be reviewed in consideration of the mutual relationship of monoamines with the other putative neurotransmitters. The complexity of epileptic pathogenesis may explain why the currently available drugs, developed according to the classic drug discovery paradigm of "one-molecule-one-target," have turned out to be effective only in a percentage of PWE. Although, no antiepileptic drugs currently target specifically monoaminergic systems, multi-target directed ligands acting on different monoaminergic proteins, present on both neurons and glia cells, may represent a new approach in the management of seizures, and their generation as well as comorbid neuropsychiatric disorders.

The Psychopharmacology Algorithm Project at the Harvard South Shore Program: An Algorithm for Generalized Anxiety Disorder

This revision of previous algorithms for the pharmacotherapy of generalized anxiety disorder was developed by the Psychopharmacology Algorithm Project at the Harvard South Shore Program. Algorithms from 1999 and 2010 and associated references were reevaluated. Newer studies and reviews published from 2008-14 were obtained from PubMed and analyzed with a focus on their potential to justify changes in the recommendations. Exceptions to the main algorithm for special patient populations, such as women of childbearing potential, pregnant women, the elderly, and those with common medical and psychiatric comorbidities, were considered. Selective serotonin reuptake inhibitors (SSRIs) are still the basic first-line medication. Early alternatives include duloxetine, buspirone, hydroxyzine, pregabalin, or bupropion, in that order. If response is inadequate, then the second recommendation is to try a different SSRI. Additional alternatives now include benzodiazepines, venlafaxine, kava, and agomelatine. If the response to the second SSRI is unsatisfactory, then the recommendation is to try a serotonin-norepinephrine reuptake inhibitor (SNRI). Other alternatives to SSRIs and SNRIs for treatment-resistant or treatment-intolerant patients include tricyclic antidepressants, second-generation antipsychotics, and valproate. This revision of the GAD algorithm responds to issues raised by new treatments under development (such as pregabalin) and organizes the evidence systematically for practical clinical application.

Alleviation of pain in painful diabetic neuropathy

INTRODUCTION

Painful diabetic neuropathy (PDN) is a disabling pain condition. Its pathomechanism remains unknown, but a sensitization and neuronal hyperexcitabilty have been suggested. Only symptomatic pharmacological pain management treatment is currently available.

AREAS COVERED

The origin of PDN is enigmatic, and the evidence-based therapeutic guidelines therefore consist only of antidepressants and antiepileptics as first-line recommended drugs. This article relates to a MEDLINE/PubMed systematic search (2005-2015).

EXPERT OPINION

The results of the meta-analysis from the aspect of the efficacy of amitriptyline, duloxetine, venlafaxine, gabapentin and pregabalin are favorable, but the placebo response rate is relatively high in patients with neuropathic pain. For personalization of the medication of PDN patients, the optimum dosing, the genotyping of the metabolizing enzymes and optimum biomarkers are needed. As concerns the future perspectives, specific sodium channel subtype inhibitors acting on peripheral nociceptive neurons or modified T-type voltage-gated calcium channel blockers may be promising targets for pharmaceutical innovations. Another attractive strategy for the treatment is based on the effects of monoclonal antibodies against nerve growth factor, sodium channels, specific receptor and cytokines. Botulinum toxin A, capsaicin patch and spinal cord stimulation therapies are the nearest future therapeutic options for the treatment of PDN patients.

Treatment of major depressive disorders with generic duloxetine and paroxetine: a multi-centered, double-blind, double-dummy, randomized controlled clinical trial

Background

This study is a pre-registration trial of generic duloxetine that was approved by the China Food and Drug Administration (approval number: 2006L01603).

Aims

Compare the treatment efficacy and safety of generic duloxetine to that of paroxetine in patients with major depressive disorders (MDD).

Methods

This was a double-dummy, double-blind, multicenter, positive drug (paroxetine), parallel randomized controlled clinical trial. The 299 patients with MDD recruited for the study were randomly assigned to use duloxetine (n=149; 40–60 mg/d) or paroxetine (n=150; 20 mg/d) for 8 weeks. The Hamilton Depression rating scale (HAMD-17) was administered at baseline and 1, 2, 4, 6, and 8 weeks after starting treatment. Remission was defined as a HAMD-17 score below 8 at the end of the trial, and treatment effectiveness was defined as a decrease in baseline HAMD-17 score of at least 50% by the end of the trial. Safety was assessed based on the reported prevalence and severity of side effects and changes in laboratory and electrocardiographic findings. Three patients in the duloxetine group dropped out before starting medication, so results were analyzed using a modified intention-to-treat (ITT) method with 146 in the experimental group and 150 in the control group.

Results

Both groups experienced 29 dropouts during the 8-week trial. HAMD-17 scores decreased significantly from baseline throughout the trial in both groups. Based on the ITT analysis, at the end of the trial there was no significant difference between the duloxetine group and the paroxetine group in effectiveness (67.1% v. 71.3%, X²=0.62 p=0.433), remission rate (41.1% v. 51.3%, X²=3.12, p=0.077), or in the incidence of side effects (56.8% v. 54.7%, X²=0.14, p=0.705).

Conclusions

Generic duloxetine is as effective and safe as paroxetine in the acute treatment of patients with MDD who seek care at psychiatric outpatient departments in China.

Update on managing generalized anxiety disorder in older adults

With the recent updates to the Diagnostic and Statistical Manual of Mental Disorders (5th edition; DSM-5), there are many questions on how to care for older adults with generalized anxiety disorder (GAD) and other psychiatric conditions. The current article reviews the new changes to the DSM-5 for diagnosis of GAD, discusses new anxiety assessment scales that are validated in older adults, evaluates pharmacological agents that have been studied in older adults for GAD treatment, and provides monitoring recommendations to help those who provide care to older adults experiencing GAD.

Reduction of patient-reported antidepressant side effects, by type of collaborative care

OBJECTIVE

Antidepressants are effective for treating depression, and collaborative care increases initiation of and adherence to antidepressants. Side effects of antidepressants are common and can adversely affect quality of life. Care managers address antidepressant side effects directly, but the impact of collaborative care on adverse effects is unknown. This secondary data analysis tested the hypothesis that patient-reported antidepressant side effects were lower for depressed patients receiving high-intensity, telemedicine-based collaborative care (TBCC) than for patients receiving low-intensity, practice-based collaborative care (PBCC).

METHODS

This analysis used data from 190 patients enrolled in a pragmatic, multisite, comparative-effectiveness trial from 2007 to 2009 and followed for 18 months. Most patients were female (83%) and Caucasian (80%). The mean age was 50. Patients randomly assigned to PBCC received 12 months of evidence-based care from an on-site primary care provider and nurse care manager. Patients in TBCC received evidence-based care from an on-site primary care provider supported by a nurse care manager available off site by telephone, as well as by a telepharmacist, telepsychologist, and telepsychiatrist. Telephone interviews completed at baseline, six, 12, and 18 months included assessments of sociodemographic characteristics, beliefs about antidepressant treatment, depression severity, psychiatric comorbidity, medications, adherence, and side effects.

RESULTS

With controls for baseline case mix and time-variant medication characteristics, the TBCC group reported significantly fewer side effects at six and 12 months (p=.008 and .002, respectively). The number of antidepressants prescribed increased risk of side effects (p=.02).

CONCLUSIONS

Patients in the TBCC group reported fewer antidepressant-related side effects, which may have contributed to improved quality of life.

Bioactivation potential of thiophene-containing drugs

Thiophene is a five-membered, sulfur-containing heteroaromatic ring commonly used as a building block in drugs. It is considered to be a structural alert, as its metabolism can lead to the formation of reactive metabolites. Thiophene S-oxides and thiophene epoxides are highly reactive electrophilic thiophene metabolites whose formation is cytochrome P450-dependent. These reactive thiophene-based metabolites are quite often responsible for drug-induced hepatotoxicity. Tienilic acid is an example of a thiophene-based drug that was withdrawn from the market after only a few months of use, due to severe cases of immune hepatitis. However, inclusion of the thiophene moiety in drugs does not necessarily result in toxic effects. The presence of other, less toxic metabolic pathways, as well as an effective detoxification system in our body, protects us from the bioactivation potential of the thiophene ring. Thus, the presence of a structural alert itself is insufficient to predict a compound's toxicity. The question therefore arises as to which factors significantly influence the toxicity of thiophene-containing drugs. There is no easy way to answer this question. However, the findings presented here indicate that, for a number of reasons, daily dose and alternative metabolic pathways are important factors when predicting toxicity and will therefore be discussed together with examples.

The efficacy and safety of duloxetine in a multidrug regimen for chronic prostatitis/chronic pelvic pain syndrome

OBJECTIVE

To evaluate the efficacy and safety of duloxetine hydrochloride in the treatment of patients affected by chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS).

METHODS

Thirty-eight CP/CPPS patients completed the National Institutes of Health Chronic Prostatitis Symptom Index (NIH-CPSI) and International Index of Erectile Function-Erectile Function-5 (IIEF-5) questionnaires, uroflowmetry, and evaluation of psychologic status using Hamilton Anxiety Scale (HAM-A) and Hamilton Depression Scale (HAM-D). Patients were randomly assigned to 2 treatments groups. Treatment in group 1 consisted of a simultaneous oral administration of tamsulosin (0.4 mg/d, 60 mg/d), saw palmetto (320 mg/d), and duloxetine (60 mg/d). Treatment in group 2 consisted of tamsulosin (0.4 mg/d) and saw palmetto (320 mg/d). NIH-CPSI and IIEF-5 questionnaires, uroflowmetry, and evaluation of the psychological status were repeated at 16 weeks of follow-up.

RESULTS

At 16 weeks, a significant improvement in NIH-CPSI pain subscore, NIH-CPSI quality of life subscore, and NIH-CPSI total score were observed in group 1 patients compared with those in group 2 (P <.01, respectively), together with a significant improvement in HAM-A and HAM-D scores (P <.01, respectively). Patients in group 2 showed a significant improvement in NIH-CPSI total score, in the urinary symptoms subscore, and in the HAM-A total score. No significant differences were observed in IIEF-5 scores in the 2 groups. Maximum flow rate significantly increased in both groups. In group 1, 20% of patients stopped the study due to adverse effects.

CONCLUSION

The use of duloxetine in a multimodal treatment with an α-blocker medication and a saw palmetto extract allowed better results in controlling clinical symptoms, psychologic status and quality of life patients affected by CP/CPPS.

Comprehensive review of generalized anxiety disorder in primary care in Europe

OBJECTIVE

This review aims to summarize meta-analyses and other relevant data relating to the efficacy and safety of the various treatment options for generalized anxiety disorder (GAD) in Europe. In addition, it will provide an overview of the prevalence, burden, and recognition of the disorder, with a view to raise awareness of GAD and inform primary care practitioners.

RESEARCH DESIGN AND METHODS

Relevant research or review articles on psychological or pharmacological treatments for GAD published in the English language between March 2006 and March 2012 were identified via a literature search in PubMed and ISI Web of Knowledge and from the Cochrane Library. Other relevant references/clinical guidelines were individually selected by the authors.

RESULTS

Prevalence rates of GAD vary across Europe but its economic and social burden is increasing. A large proportion of patients with GAD present with symptoms in primary care. However, due to the disorder's complexity and the incidence of comorbid diseases, some primary care physicians may lack the knowledge or confidence to effectively recognize, manage, and/or treat the disorder. This is despite psychological and pharmacological treatments being available for the effective management of GAD.

CONCLUSIONS

GAD remains a difficult disorder to detect and comorbid complications add to its economic and social burden. Early detection and intervention reduces the societal burden and improves GAD patients' quality of life and functional ability. Primary care practitioners play a key role in identifying and treating patients with GAD.

Duloxetine in affective disorders: a naturalistic study on psychiatric and medical comorbidity, use in association and tolerability across different age groups

Objective:

Duloxetine, a selective serotonin and norepinephrine reuptake inhibitor (SNRI), is currently approved in many countries for the treatment of Major Depressive Disorder (MDD) and Generalized Anxiety Disorder (GAD). The present naturalistic study was aimed to investigate tolerability of Duloxetine in a sample of patients with affective disorders and psychiatric/medical comorbidity, comparing tolerability in monotherapy versus polytherapy and across different age groups.

Methods:

The sample included 165 patients, affected by anxiety and/or mood disorders with or without comorbidity, who had been taken Duloxetine for at least 1 month. Sample variables were collected through a retrospective chart review.

Results:

Most common primary diagnoses were MDD (49.1 %), Bipolar Disorder (BD) (15.7 %) and GAD (5.5%). The 40 % of the sample had psychiatric comorbidity: in particular, anxiety disorders (15.8 %) (GAD 7.9%, Panic Disorder –PD- 7.3%) and personality disorders (9.1%) as the most frequent ones. With respect to medical comorbidities (68% of the sample), hypertension (12.1%) and diabetes (7.3%) were the most common ones. Mean duration of treatment and dosage of Duloxetine were, respectively, 11 months (± 9.1) and 70 mg/day (± 28.6). The 68 % of the sample received Duloxetine in association with other drugs. Minor side-effects, in particular drowsiness and gastrointestinal problems, were reported by 15 % of the sample. No difference in terms of tolerability across distinct groups, divided on the basis of mono- vs polytherapy as well as of different age, was found.

Conclusion:

Duloxetine, mostly administered in patients with affective disorders with psychiatric/ medical comorbidity and in association with other drugs, appeared to be well tolerated, showing limited rates of side effects of mild intensity. Further naturalistic studies are warranted to confirm present results.

The role of the NMDA receptors and l-arginine-nitric oxide-cyclic guanosine monophosphate pathway in the antidepressant-like effect of duloxetine in the forced swimming test

Duloxetine is a selective serotonin and noradrenaline reuptake inhibitor used as antidepressant. However, its mechanisms of action are not fully understood. This study investigated the effect of duloxetine in the mouse forced swimming test (FST) and in the tail suspension test (TST) and the involvement of the NMDA receptors and the l-arginine-NO-cGMP pathway in its effect in the FST. Duloxetine reduced the immobility time both in the FST and in the TST (dose range of 1-30mg/kg, i.p.), without changing locomotion in an open-field. Duloxetine administered orally (1-30mg/kg) also reduced the immobility time in the FST. The effect of duloxetine (10mg/kg, p.o.) in the FST was prevented by pre-treatment with NMDA (0.1pmol/site, i.c.v.), d-serine (30μg/site, i.c.v.), (l-arginine (750mg/kg, i.p.), S-nitroso-N-acetyl-penicillamine (SNAP, 25μg/site, i.c.v) or sildenafil (5mg/kg, i.p.). The administration of MK-801 (0.001mg/kg, i.p.), 7-nitroindazole (50mg/kg, i.p.), methylene blue (20mg/kg, i.p.) or 1H-[1,2,4]oxadiazole[4,3-a]quinoxalin-1-one (ODQ) (30pmol/site i.c.v.) in combination with a sub-effective dose of duloxetine (0.3mg/kg, p.o.) reduced the immobility time in the FST. Moreover, the administration of duloxetine (10mg/kg) produced a reduction in NOx levels in the hippocampus and cerebral cortex. Altogether the results suggest that the effect of duloxetine in the FST is dependent on either a blockade of NMDA receptors or an inhibition of NO. In addition, our results further reinforce the role of NMDA receptors and l-arginine-NO-cGMP pathway, besides the monoaminergic systems, in the mechanism of action of current prescribed antidepressant agents.

Duloxetine blocks cloned Kv4.3 potassium channels

The effects of duloxetine were examined on cloned Kv4.3 channels stably expressed in CHO cells using the whole-cell patch-clamp technique. Duloxetine decreased the peak amplitude of Kv4.3 currents with an acceleration of the decay rate of current inactivation in a concentration-dependent manner. The IC(50) values required for the blocking effects of duloxetine on the peak amplitude and the integral of currents were 8.4 and 2.1μM, respectively. Duloxetine accelerated the rate of inactivation of Kv4.3 currents and thereby decreased the time-to-peak in a concentration-dependent manner. Analysis of the time dependence of the drug block produced estimates of 21.9μM(-1)s(-1) and 165.9s(-1), for the respective association (k(+1)) and dissociation (k(-1)) rate constants. The K(d) value (k(-1)/k(+1)) yielded 7.5μM, which approximates the experimental IC(50) value obtained from the concentration-response curve. The block of Kv4.3 by duloxetine was voltage-dependent at a membrane potential coinciding with the activation of the channels. At a more positive potential, however, the block was relieved. Duloxetine produced a hyperpolarizing shift in the voltage dependence of the steady-state inactivation of Kv4.3, and accelerated the closed-state inactivation of Kv4.3 in the subthreshold voltage range. Duloxetine induced a significant use-dependent block at frequencies of 1 and 2Hz. In the presence of duloxetine, the recovery from inactivation was slower than under control conditions. These results demonstrate that duloxetine exerts a concentration-dependent block of Kv4.3 by binding to the channels in the open and inactivated states and these actions may contribute to its analgesic effect in neuropathic pain.

Developmental influence of the serotonin transporter on the expression of npas4 and GABAergic markers: modulation by antidepressant treatment

Alterations of the serotonergic system are involved in the pathophysiology of mood disorders and represent an important target for its pharmacological treatment. Genetic deletion of the serotonin transporter (SERT) in rodents leads to an anxious and depressive phenotype, and is associated with reduced neuronal plasticity as indicated by decreased brain-derived neurotrophic factor (Bdnf) expression levels. One of the transcription factors regulating Bdnf is the neuronal PAS domain protein 4 (Npas4), which regulates activity-dependent genes and neuroprotection, and has a critical role in the development of GABA synapses. On the basis of these premises, we investigated the expression of Npas4 and GABAergic markers in the hippocampus and prefrontal cortex of homozygous (SERT(-/-)) and heterozygous (SERT(+/-)) knockout rats, and analyzed the effect of long-term duloxetine treatment on the expression of these targets. We found that Npas4 expression was reduced in both the brain structures of adult SERT(+/-) and SERT(-/-) animals. This effect was already present in adolescent SERT(-/-), and could be mimicked by prenatal exposure to the antidepressant fluoxetine. Moreover, SERT(-/-) rats showed a strong impairment of the GABAergic system, as indicated by the reduction of several markers, including the vesicular transporter (Vgat), glutamic acid decarboxylase-67 (Gad67), the receptor subunit GABA A receptor, gamma 2 (GABA(A)-γ2), and calcium-binding proteins that label subgroups of the GABAergic neurons. Interestingly, chronic treatment with the antidepressant duloxetine was able to restore the physiological levels of Npas4 and GABAergic markers in SERT(-/-) rats, although some differences in the modulation of GABAergic genes exist between hippocampus and prefrontal cortex. Our results demonstrate that SERT knockout rats, an animal model of mood disorders, have reduced Npas4 expression that correlates with decreased expression of Bdnf exon I and IV. These changes lead to an impairment of the GABAergic system that may contribute to the anxious and depressive phenotype associated with inherited SERT downregulation.

Clinically significant drug interactions with newer antidepressants

After the introduction of selective serotonin reuptake inhibitors (SSRIs), other newer antidepressants with different mechanisms of action have been introduced in clinical practice. Because antidepressants are commonly prescribed in combination with other medications used to treat co-morbid psychiatric or somatic disorders, they are likely to be involved in clinically significant drug interactions. This review examines the drug interaction profiles of the following newer antidepressants: escitalopram, venlafaxine, desvenlafaxine, duloxetine, milnacipran, mirtazapine, reboxetine, bupropion, agomelatine and vilazodone. In general, by virtue of a more selective mechanism of action and receptor profile, newer antidepressants carry a relatively low risk for pharmacodynamic drug interactions, at least as compared with first-generation antidepressants, i.e. monoamine oxidase inhibitors (MAOIs) and tricyclic antidepressants (TCAs). On the other hand, they are susceptible to pharmacokinetic drug interactions. All new antidepressants are extensively metabolized in the liver by cytochrome P450 (CYP) isoenzymes, and therefore may be the target of metabolically based drug interactions. Concomitant administration of inhibitors or inducers of the CYP isoenzymes involved in the biotransformation of specific antidepressants may cause changes in their plasma concentrations. However, due to their relatively wide margin of safety, the consequences of such kinetic modifications are usually not clinically relevant. Conversely, some newer antidepressants may cause pharmacokinetic interactions through their ability to inhibit specific CYPs. With regard to this, duloxetine and bupropion are moderate inhibitors of CYP2D6. Therefore, potentially harmful drug interactions may occur when they are coadministered with substrates of these isoforms, especially compounds with a narrow therapeutic index. The other new antidepressants are only weak inhibitors or are not inhibitors of CYP isoforms at usual therapeutic concentrations and are not expected to affect the disposition of concomitantly administered medications. Although drug interactions with newer antidepressants are potentially, but rarely, clinically significant, the use of antidepressants with a more favourable drug interaction profile is advisable. Knowledge of the interaction potential of individual antidepressants is essential for safe prescribing and may help clinicians to predict and eventually avoid certain drug combinations.

Evidence for a differential opioidergic involvement in the analgesic effect of antidepressants: prediction for efficacy in animal models of neuropathic pain?

BACKGROUND AND PURPOSE

Antidepressants are one of the recommended treatments for neuropathic pain. However, their analgesic action remains unpredictable, and there are no selection criteria for clinical use. Better knowledge of their mechanism of action could help highlight differences underlying their unequal efficacy.

EXPERIMENTAL APPROACH

We compared the activity of a tricyclic antidepressant (clomipramine) with selective 5-HT and noradrenaline reuptake inhibitors (milnacipran and duloxetine) in streptozocin-induced diabetic and chronic constriction nerve injury-induced neuropathic rats, after repeated injections. We looked for an opioidergic mechanism in their action.

KEY RESULTS

Abolition of mechanical hyperalgesia was observed in mononeuropathic rats after five injections of clomipramine (5 mg·kg(-1) , s.c.) and milnacipran (10 or 20 mg·kg(-1) , i.p.) and in diabetic rats after clomipramine. An additional antinociceptive effect was obtained with five injections of duloxetine (3 mg·kg(-1) , i.p.) in both models and milnacipran (10 mg·kg(-1) , i.p.) in diabetic rats. These effects were observed with plasma antidepressant concentrations similar to those found in patients treated for neuropathic pain. Naloxone (1 mg·kg(-1) , i.v.) only suppressed the anti-hyperalgesic effects of clomipramine in both models of pain and of milnacipran in the traumatic model.

CONCLUSIONS AND IMPLICATIONS

The opioid system appears to be involved in the mechanism of action of antidepressants that only have an anti-hyperalgesic effect but not in those that have a stronger (i.e. antinociceptive) effect. These differences between the antidepressants occurred whatever the aetiology of the neuropathy and, if confirmed in clinical trials, could be used to decide which antidepressant is administered to a patient with neuropathic pain.

Duloxetine for the treatment of mood disorder in cancer patients: a 12-week case-control clinical trial

OBJECTIVE

The aim of this study was to investigate the efficacy and tolerability of duloxetine in cancer patients with mood disorder (MD) by means of a comparison with a matched control group of patients with MD without medical illness.

METHODS

Fifty-nine consecutive patients with MD were enrolled in this prospective case-control study and received duloxetine 60/120 mg per day for 12 weeks. Twenty-seven patients were affected by cancer, whereas 32 had an MD without cancer. All the patients were assessed by means of efficacy and effectiveness tolerability scales for depression (Montgomery-Asberg Depression Rating Scale and Hospital Anxiety and Depression Scale), anxiety (State-Trait Anxiety Inventory-Y1/Y2) and severity of symptoms (Clinical Global Impression (CGI)-Severity) at baseline (T0), after 4 weeks (T1) and 12 weeks (T2). The CGI-Improvement, CGI-Effectiveness Index and Dosage Record Treatment Emergent Symptom Scale were administered at T1 and T2.

RESULTS

A significant global improvement in all the efficacy measures was found. The results showed no significant interaction 'Time X Group', suggesting a similar improvement in efficacy scores for cancer-depressed patients and depressed patients without cancer. No difference was found between the two groups with regard to drop-out percentage, effectiveness and tolerability.

CONCLUSION

Although the results of this case-control study are preliminary, they suggest that duloxetine can be considered a good option for the treatment of MD in cancer patients.

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.

Duloxetine in the treatment of adolescents with attention deficit/hyperactivity disorder: an open-label study

OBJECTIVE

The main aim of this study was to explore the efficacy and safety of duloxetine, a serotonin and norepinephrine reuptake inhibitor, in the treatment of adolescents with attention deficit/hyperactivity disorder (ADHD).

METHODS

Seventeen adolescents aged 11-18 years, diagnosed with ADHD, participated in this 6-week open-label study. Duloxetine was given in doses of 30 mg/day in the first week and 60 mg/day from week 2 to the end of the study. Conners' Parent Rating Scale-Revised (CPRS-R) short form was used to assess the efficacy of the therapy.

RESULTS

A significant reduction in ADHD symptoms measured by CPRS-R was observed. This reduction was evident from week 4 of the study. In addition, the decrease was significant in all four subscales of CPRS-R including inattention, oppositionality, hyperactivity and ADHD index. In terms of side effects, duloxetine was generally safe and well tolerated.

CONCLUSIONS

The results of this open-label study suggest a promise of duloxetine in the treatment of youth with ADHD. Further controlled studies with larger samples are required to evaluate the efficacy of duloxetine in children and adolescents with ADHD.

The effect of coadministration of duloxetine on steady-state serum concentration of risperidone and aripiprazole: a study based on therapeutic drug monitoring data

Previous studies have categorized duloxetine as a moderate inhibitor of CYP2D6. The aim of the present study was to investigate the potential interactions between duloxetine and the two CYP2D6 substrates risperidone and aripiprazole in psychiatric patients. Serum concentration data from patients treated with risperidone (n = 8) or aripiprazole (n = 7) in combination with duloxetine were retrieved from therapeutic drug monitoring files at the Center for Psychopharmacology, Diakonhjemmet Hospital, Oslo, Norway. The degree of interaction was assessed by comparing the data with a control group of CYP2D6-genotyped patients (homozygous "extensive metabolizers") using oral risperidone or aripiprazole without duloxetine. Coadministration of duloxetine did not significantly increase the concentration of the parent drug or the parent drug/metabolite ratio of either risperidone or aripiprazole. The present study therefore indicates that duloxetine may safely be used concomitantly with risperidone or aripiprazole.

An open, non-randomised comparison of escitalopram and duloxetine for the treatment of subjects with Generalized Anxiety Disorder

OBJECTIVES

This study compares the effectiveness of a 6-months treatment with escitalopram (ESC), a selective serotonin reuptake inhibitor, or duloxetine (DUL), a balanced serotonin and nor-adrenaline reuptake inhibitor, in 43 subjects with Generalized Anxiety Disorder (GAD).

METHODS

Assessment was made with the Hamilton Anxiety and Depression scales (HAM-A; HAM-D), with the CGI, and with the GAF at T0 (intake), T1, T3, T6 (1, 3, and 6 months later). The comparison among the two treatment groups (ESC=20; DUL=23) at the four endpoints was made through a GLM-ANOVA for repeated measures. Rates of remission (HAM-A<7), response (HAM-A reduction of 50% or above) and dropout were evaluated.

RESULTS

At 1, 3, and 6 months after treatment inception both treatment groups showed a significant improvement in the scores of CGI, HAMA, HAM-D, and GAF, and an equivalent rate of dropout. The DUL group registered a greater amount of remission and response rates at T1 against the ESC group in all the scales except in the HAM-D scale. Duloxetine was more effective than escitalopram after the first month of treatment only in the somatic subscale of HAM-A. The presence of a cluster C personality disorder was associated in both groups to greater difficulties in attaining remission and to dropout.

CONCLUSIONS

Implications for clinical practice are discussed.

Synthesis and structure-activity studies of benzyl ester meperidine and normeperidine derivatives as selective serotonin transporter ligands

A series of benzyl esters of meperidine and normeperidine were synthesized and evaluated for binding affinity at serotonin, dopamine and norepinephrine transporters. The 4-methoxybenzyl ester 8b and 4-nitrobenzyl ester 8c in the meperidine series and 4-methoxybenzyl ester 14a in the normeperidine series exhibited low nanomolar binding affinities at the SERT (K(i) values <2nM) and high SERT selectivity (DAT/SERT >1500 and NET/SERT >1500).

Pharmacotherapy Update: Pregabalin in the Treatment of Generalized Anxiety Disorder

Generalized anxiety disorder (GAD) is a common disorder that is chronic, disabling, and often goes undiagnosed. Currently, four distinct classes of medications have demonstrated efficacy in the treatment of GAD: benzodiazepines, serotonin and/or norepinephrine reuptake inhibitors (SSRIs/SNRIs), histamine H1 receptor blockers (hydroxyzine), and pregabalin. Pregabalin acts via binding to an α2-δ subunit presynaptic membrane protein that inhibits neurotransmitter release in excited neurons. Pregabalin is renally excreted and undergoes minimal (<2%) hepatic metabolism, thus limiting the risk of drug–drug interactions. The efficacy of pregabalin for the treatment of GAD has been established based on the results of 8 double-blind, placebo-controlled, short-term led trials, and one 6-month relapse prevention study. The current review summarizes data showing that pregabalin has a significantly different safety profile from the benzodiazepines (eg, less sedation, less cognitive and psychomotor impairment, less risk of dependence and withdrawal), and SSRI/SNRI anxiolytics (eg, less gastrointestinal side effects and sexual dysfunction). The review also summarizes efficacy data showing that pregabalin is a broad spectrum anxiolytic that with a speed of onset similar to the benzodiazepines.

Synthesis and monoamine transporter affinity of 3alpha-arylmethoxy-3beta-arylnortropanes

A series of 3-arylnortrop-2-enes and 3alpha-arylmethoxy-3beta-arylnortropanes were synthesized and evaluated for binding affinity at monoamine transporters. The 3-(3,4-dichlorophenyl)nortrop-2-ene (6e) exhibited high affinity for the SERT (K(i)=0.3 nM). The 3alpha-arylmethoxy-3beta-arylnortropanes were generally SERT selective with the 3alpha-(3.4-dichlorophenylmethoxy)-3betaphenylnortrop-2-ene (7c) possessing subnanomolar potency (K(i)=0.061 nM). However, 3alpha-(3,4-dichlorophenylmethoxy)-3beta-phenylnortrop-2-ene (7b) exhibited high affinity at all three transporters [(DAT K(i)=22 nM), (SERT K(i)=6 nM) and (NET K(i)=101 nM)].