Dual serotonin and noradrenaline uptake inhibitor class of antidepressants potential for greater efficacy or just hype?

Efficacy and safety of duloxetine in painful diabetic peripheral neuropathy: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Painful diabetic peripheral neuropathy (PDPN) is a key concern in clinical practice. In this systematic review and meta-analysis, we compared duloxetine and placebo treatments in terms of their efficacy and safety in patients with PDPN.

METHODS

Following the PRISMA guidelines, we searched the Cochrane Library, PubMed, and Embase databases for relevant English articles published before January 11, 2021. Treatment efficacy and safety were assessed in terms of pain improvement, patient-reported health-related performance, and patients' quality of life.

RESULTS

We reviewed a total of 7 randomized controlled trials. Regarding pain improvement, duloxetine was more efficacious than placebo (mean difference [MD] - 0.89; 95% confidence interval [CI] - 1.09 to - 0.69; P < .00001). Furthermore, duloxetine significantly improved the patients' quality of life, which was assessed using the Clinical Global Impression severity subscale (MD - 0.48; 95% CI - 0.61 to - 0.36; P < .00001), Patient Global Impression of Improvement scale (MD - 0.50; 95% CI - 0.64 to - 0.37; P < .00001), and European Quality of Life Instrument 5D version (MD 0.04; 95% CI 0.02 to 0.07; P = .0002). Severe adverse events were rare, whereas nausea, somnolence, dizziness, fatigue, constipation, and decreased appetite were common; approximately, 12.6% of all patients dropped out because of the common symptoms.

CONCLUSIONS

Duloxetine is more efficacious than placebo treatments in patients with PDPN. The rarity of severe adverse events indicates that duloxetine is safe. When a 60-mg dose is insufficient, 120 mg of duloxetine may improve PDPN symptoms. Our findings may help devise optimal treatment strategies for PDPN.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42021225451.

An Updated Systematic Review and Meta-analysis of Duloxetine for Knee Osteoarthritis Pain

OBJECTIVE

We conducted the updated systematic review and meta-analysis of the best available quantitative and qualitative evidence to evaluate the effects and safety of duloxetine for the treatment of knee osteoarthritis (OA) pain.

METHODS

A comprehensive literature search used 3 English and 4 Chinese biomedical databases from inception through July 10, 2020. We included randomized controlled trials of duloxetine with intervention duration of 2 weeks or longer for knee OA. The primary outcome was pain intensity measured by Brief Pain Inventory and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain subscale. Secondary outcome measurements included 36-Item Short Form Health Survey, Patient's Global Impression of Improvement, Clinical Global Impressions of Severity, and adverse events (AEs). The quality of all included studies was evaluated using the Cochrane risk-of-bias criteria. The review was registered in the PROSPERO (CRD 42020194072).

RESULTS

Six studies totaling 2059 patients met the eligibility criteria. Duloxetine had significant reductions in Brief Pain Inventory 24 hours average pain (mean difference [MD]=-0.74; 95% confidence interval [CI], -0.92 to -0.57; P<0.00001; I2=13%; 5 trials; 1695 patients); patient general activity (MD=-0.76; 95% CI, -0.96 to -0.56; P<0.00001; I2=0%; 5 trials; 1694 patients) WOMAC physical function subscale (MD=-4.22; 95% CI, -5.14 to -3.30; P<0.00001; I2=26%; 5 trials; 1986 patients); Patient's Global Impression of Improvement (MD=-0.48; 95% CI, -0.58 to -0.37; P<0.00001; I2=29%; 5 trials; 1741 patients); and Clinical Global Impressions of Severity (MD=-0.34; 95% CI, -0.44 to -0.24; P<0.00001; I2=0%; 4 trials; 1178 patients) compared with placebo control. However, no difference on WOMAC pain subscale (standard mean difference=-1.68; 95% CI, -3.45 to 0.08; P=0.06; I2=100%; 3 trials; 1104 patients) and in serious AEs (risk ratio=0.92; 95% CI, 0.40-2.11; P=0.84; I2=0%; 5 trials; 1762 patients) between duloxetine and placebo. Furthermore, duloxetine failed to show superior effects for improving the life quality and demonstrated more treatment-emergent AEs.

CONCLUSION

Duloxetine may be an effective treatment option for knee OA patients but further rigorously designed and well-controlled randomized trials are warranted.

Rate Dependence on Inductive and Resonance Effects for the Organocatalyzed Enantioselective Conjugate Addition of Alkenyl and Alkynyl Boronic Acids to β-Indolyl Enones and β-Pyrrolyl Enones

Two key factors bear on reaction rates for the conjugate addition of alkenyl boronic acids to heteroaryl-appended enones: the proximity of inductively electron-withdrawing heteroatoms to the site of bond formation and the resonance contribution of available heteroatom lone pairs to stabilize the developing positive charge at the enone β-position. For the former, the closer the heteroatom is to the enone β-carbon, the faster the reaction. For the latter, greater resonance stabilization of the benzylic cationic charge accelerates the reaction. Thus, reaction rates are increased by the closer proximity of inductive electron-withdrawing elements, but if resonance effects are involved, then increased rates are observed with electron-donating ability. Evidence for these trends in isomeric substrates is presented, and the application of these insights has allowed for reaction conditions that provide improved reactivity with previously problematic substrates.

Inhibition of Fast Nerve Conduction Produced by Analgesics and Analgesic Adjuvants-Possible Involvement in Pain Alleviation

Nociceptive information is transmitted from the periphery to the cerebral cortex mainly by action potential (AP) conduction in nerve fibers and chemical transmission at synapses. Although this nociceptive transmission is largely inhibited at synapses by analgesics and their adjuvants, it is possible that the antinociceptive drugs inhibit nerve AP conduction, contributing to their antinociceptive effects. Many of the drugs are reported to inhibit the nerve conduction of AP and voltage-gated Na⁺ and K⁺ channels involved in its production. Compound action potential (CAP) is a useful measure to know whether drugs act on nerve AP conduction. Clinically-used analgesics and analgesic adjuvants (opioids, non-steroidal anti-inflammatory drugs, ₂-adrenoceptor agonists, antiepileptics, antidepressants and local anesthetics) were found to inhibit fast-conducting CAPs recorded from the frog sciatic nerve by using the air-gap method. Similar actions were produced by antinociceptive plant-derived chemicals. Their inhibitory actions depended on the concentrations and chemical structures of the drugs. This review article will mention the inhibitory actions of the antinociceptive compounds on CAPs in frog and mammalian peripheral (particularly, sciatic) nerves and on voltage-gated Na⁺ and K⁺ channels involved in AP production. Nerve AP conduction inhibition produced by analgesics and analgesic adjuvants is suggested to contribute to at least a part of their antinociceptive effects.

Duloxetine plasma level and antidepressant response

BACKGROUND

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

METHODS

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

RESULTS

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

DISCUSSION

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

Duloxetine in Painful Diabetic Neuropathy: A Systematic Review

OBJECTIVE

To systematically review the evidence for duloxetine in the management of painful diabetic neuropathy (PDN).

METHODS

Electronic searches of Medline and PubMed were performed from 2005 till October 2015 using medical subject headings and free-text words. Two independent reviewers extracted the data and assessed the methodological quality of the selected studies.

RESULTS

Twenty-three studies met our inclusion criteria and 8 were considered of high quality and were included to this review. Because of heterogeneity of the studies included in this review, statistical pooling of the data was not possible. We found good evidence for use of duloxetine in PDN over placebo and pregabalin but there was no benefit of duloxetine over amitriptyline.

CONCLUSIONS

Duloxetine has a beneficial effect over placebo. Nevertheless, the evidence of superiority of duloxetine over pregabalin and amitriptyline should be explored further as there was only 1 trial for each category. Provided majority of the PDN patients share cardiovascular complications, use of duloxetine will be a good option for treating pain associated with PDN over amitriptyline. Future randomized controlled trials should be designed keeping this in mind.

Trajectories of depression symptom improvement and associated predictor analysis: An analysis of duloxetine in double-blind placebo-controlled trials

BACKGROUND

In the treatment of major depressive disorder (MDD), it is not fully understood how individual symptoms improve over time (trajectory) in remitters. This study compared symptom improvement trajectories, as measured with the 17-item Hamilton Depression Rating Scale (HAM-D17), in remitters and nonremitters.

METHODS

This analysis is based on 10 placebo-controlled, randomized, double-blind trials of duloxetine (40-60mg/day) for treatment of MDD from baseline up to week 8. Remission was defined as a HAM-D17 total score ≤7 at week 8 (last observation carried forward). Trajectories of HAM-D17 items were assessed by mixed model repeated measures analysis for treatment and remitter-nonremitter comparisons. Grouping of the trajectories was performed by factor analysis. Predictor analysis using HAM-D17 items was conducted by logistic regression.

RESULTS

There were 1555 patients in the duloxetine group (489 [31.4%] remitters) and 1206 patients in the placebo group (290 [24.0%] remitters; P<.0001). For most items, the difference in trajectories between remitters and nonremitters appeared at early time points and increased over time. Treatment response trajectories were very similar for duloxetine and placebo remitters, while duloxetine nonremitters improved more than placebo nonremitters. For duloxetine remitters, we found 3 trajectory groups of HAM-D17 items. The predictor analysis showed that improvement in 6 individual items at week 1 or 2 was significantly associated with remission at week 8.

LIMITATIONS

Generalizability of these results may be limited by the relatively short observation period used to define remission.

CONCLUSIONS

Early monitoring of some symptoms of depression may prove useful in guiding treatment decisions.

Changes in energy during treatment of depression: an analysis of duloxetine in double-blind placebo-controlled trials

AIMS

The aim of this study was to assess how quickly and effectively duloxetine improves energy compared with placebo in patients with major depressive disorder (MDD).

METHODS

Data from 10 randomised, double-blind, placebo-controlled clinical trials examining duloxetine (40-60 mg/day) vs. placebo in patients diagnosed with MDD were analysed. Change from baseline at Week 1 through Week 8 in Hamilton Depression Rating Scale (HAM-D) retardation subscale score (Item 1 - depressed mood, Item 7 - work and activities, Item 8 - retardation and Item 14 - genital symptoms) was assessed with mixed model repeated measures analysis. Positive predictive values and negative predictive values were calculated for predictor analysis.

RESULTS

Patients treated with duloxetine (N = 1522) experienced statistically significantly (p ≤ 0.05) greater reductions in HAM-D retardation subscale scores vs. placebo (N = 1180) starting at Week 1 throughout Week 8 of treatment. Of the patients with early energy improvement (≥ 20% reduction in HAM-D retardation subscale scores) at Week 1, 48% achieved remission (HAM-D total score ≤ 7) at Week 8; 48% and 46% of patients who experienced early energy improvement at Weeks 2 and 4, respectively, achieved remission at Week 8.

DISCUSSION

We demonstrated that treatment with duloxetine, quickly and with increasing magnitude over treatment time, improves low energy symptoms. As early as 1 week after starting treatment with duloxetine, improvement of low energy may serve as a predictor of remission at end-point.

CONCLUSIONS

Treatment with duloxetine improves energy in patients with MDD and early response in retardation may serve as a modest predictor of remission at end-point.

CLINICAL TRIALS REGISTRATION

ClinicalTrials.gov. Study Identifiers: NCT00036335; NCT00073411; NCT00406848 and NCT00536471. Studies HMAQa, HMAQb, HMATa, HMATb, HMBHa and HMBHb predate the registration requirement.

DATA POSTING

ClinicalTrials.gov. Study Identifiers: NCT00406848; NCT00536471.

Neuronal and immunological basis of action of antidepressants in chronic pain - clinical and experimental studies

The current knowledge of the pharmacological actions of the tricyclic antidepressants (TCAs) has slowly evolved through their over 40-year history. Chronic pain represents one of the most important public health problems, and antidepressants are an essential part of the therapeutic strategy in addition to classical analgesics. This article reviews the available evidence on the efficacy and safety of antidepressants in chronic pain conditions; namely, headaches, low back pain, fibromyalgia, cancer pain and especially neuropathic pain. TCAs are traditionally the main type of depression medication used to treat chronic pain. Recently, new antidepressants were introduced into clinical use, with a significant reduction in side effects and equivalent efficacy on mood disorders. These new drugs that are effective for chronic pain belong to the tetracyclic antidepressants (TeCAs) group (amoxapine, maprotiline), the serotonin and noradrenaline reuptake inhibitors (SNRIs) group (duloxetine, venlafaxine, milnacipran) and the atypical antidepressants group (bupropion, trazodone, mirtazapine, nefazodone). In this review, we present the available publications on TCAs (amitriptyline, doxepin, imipramine, desipramine, nortriptyline), TeCAs (amoxapine, maprotiline), selective serotonin reuptake inhibitors (SSRIs) (citalopram, fluoxetine, paroxetine), SNRIs (duloxetine, venlafaxine, milnacipran) and atypical antidepressants (bupropion) for the treatment of neuropathic pain. We also review analgesics acting as both opioid receptor agonists and also acting as aminergic reuptake inhibitors. Existing data are insufficient to conclude which of these new classes of antidepressants has the best clinical profile and will be the most effective in the treatment of neuropathic pain; in addition, a lower incidence of side effects should be considered. Increased experimental and translational research is a key for further improvement of the treatment of chronic pain with antidepressants. However, evidence from basic science is needed to improve our understanding of the mechanisms of action and their possible pharmacodynamic interactions.

Superiority of duloxetine to placebo in improving diabetic neuropathic pain: Results of a randomized controlled trial in Japan

Aims/Introduction:  Duloxetine has been suggested to exert analgesic effects by activating the descending inhibitory system through inhibition of serotonin (5‐HT) and noradrenaline (NA) reuptake. This randomized controlled trial investigated the efficacy and safety of duloxetine in Japanese patients with diabetic neuropathic pain (DNP).

Materials and Methods:  Duloxetine 40 or 60 mg/day or placebo was given orally once daily for 12 weeks. The primary efficacy measure was weekly mean 24‐h average pain severity score on the 11‐point Numerical Rating Scale.

Results:  At 12 weeks vs baseline, the 24‐h average pain score (adjusted mean ± SE) was significantly improved in the combined duloxetine (−2.47 ± 0.18) and duloxetine 40 mg (−2.41 ± 0.21) and 60 mg groups (−2.53 ± 0.21) as compared with the placebo group (−1.61 ± 0.18). Duloxetine also exerted significant improvements over the placebo in nearly all secondary outcome measures including 24‐h worst pain, night pain, Brief Pain Inventory (BPI) pain scores, Patient’s Global Impression of Improvement (PGI‐I) and health outcome measures, namely, various BPI interference scores. The incidence of adverse events (AE) was higher in the duloxetine groups than in the placebo group (duloxetine overall, 84.8%; duloxetine 40 mg, 84.7%; duloxetine 60 mg, 84.9%; placebo, 73.7%). Most AE were mild or moderate in severity, and resolved or relieved. There were no clinically significant safety concerns.

Conclusions:  Duloxetine 40 or 60 mg/day showed superiority over the placebo at reducing pain scores in patients with DNP. Duloxetine is safe, efficacious and clinically useful in the management of DNP. This trial was registered with ClinicalTrials.gov (no. NCT‐00552175). (J Diabetes Invest, doi: 10.1111/j.2040‐1124.2010.00073.x, 2010)

Antidepressant-like effects of 071031B, a novel serotonin and norepinephrine reuptake inhibitor

SNRIs (serotonin and norepinephrine reuptake inhibitors) have been proposed to exert increased therapeutic efficacy or be faster acting compared to commonly used antidepressants. In this study, we performed in vitro binding and uptake assays and in vivo behavioral tests to assess the pharmacological properties and antidepressant-like efficacy of the compound 071031B; we also performed cytotoxicity tests using HepG2 cells and SH-SY5Y cells to predict the toxicity of 071031B. In vitro, 071031B had high affinity for both serotonin transporters and norepinephrine transporters prepared from rat cortex tissue (Ki=2.68 and 1.09 nM, respectively) and recombinant cells (Ki=1.57 and 0.36 nM, respectively). Moreover, 071031B also potently inhibited the uptake of serotonin (5-HT) and norepinephrine (NE) into rat cortical synaptosomes (Ki=1.99 and 1.09 nM, respectively) and recombinant cells (Ki=3.23 and 0.79 nM, respectively). In vivo, acute administration of 071031B dose-dependently reduced the immobility time in the tail suspension test in mice and the forced swimming test in mice and rats with higher efficacy than duloxetine and showed no stimulatory effect on the locomotor activity. Chronic 071031B treatment (5 or 10mg/kg) significantly reversed depressive-like behaviors in chronically stressed rats, including reduced sucrose preference, decreased locomotor activity, and prolonged latency to begin eating. Furthermore, 071031B also exhibited lower cytotoxicity in HepG2 cells and SH-SY5Y cells in vitro than duloxetine. These findings suggest that 071031B is a novel, balanced serotonin and norepinephrine reuptake inhibitor, with more potent antidepressant effects and lower hepatotoxicity and neurotoxicity in vitro than duloxetine.

The solute carrier 6 family of transporters

The solute carrier 6 (SLC6) family of the human genome comprises transporters for neurotransmitters, amino acids, osmolytes and energy metabolites. Members of this family play critical roles in neurotransmission, cellular and whole body homeostasis. Malfunction or altered expression of these transporters is associated with a variety of diseases. Pharmacological inhibition of the neurotransmitter transporters in this family is an important strategy in the management of neurological and psychiatric disorders. This review provides an overview of the biochemical and pharmacological properties of the SLC6 family transporters.

Duloxetine versus other anti-depressive agents for depression

BACKGROUND

Although pharmacological and psychological interventions are both effective for major depression, in primary and secondary care settings antidepressant drugs remain the mainstay of treatment. Amongst antidepressants many different agents are available. Duloxetine hydrochloride is a dual reuptake inhibitor of serotonin and norepinephrine and has been licensed by the Food and Drug Administration in the US for major depressive disorder (MDD), generalised anxiety disorder, diabetic peripheral neuropathic pain, fibromyalgia and chronic musculoskeletal pain.

OBJECTIVES

To assess the evidence for the efficacy, acceptability and tolerability of duloxetine in comparison with all other antidepressant agents in the acute-phase treatment of major depression.

SEARCH METHODS

MEDLINE (1966 to 2012), EMBASE (1974 to 2012), the Cochrane Collaboration Depression, Anxiety and Neurosis Controlled Trials Register and the Cochrane Central Register of Controlled Trials up to March 2012. No language restriction was applied. Reference lists of relevant papers and previous systematic reviews were hand-searched. Pharmaceutical company marketing duloxetine and experts in this field were contacted for supplemental data.

SELECTION CRITERIA

Randomised controlled trials allocating patients with major depression to duloxetine versus any other antidepressive agent.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and a double-entry procedure was employed. Information extracted included study characteristics, participant characteristics, intervention details and outcome measures in terms of efficacy, acceptability and tolerability.

MAIN RESULTS

A total of 16 randomised controlled trials (overall 5735 participants) were included in this systematic review. Of these, three trials were unpublished. We found 11 studies (overall 3304 participants) comparing duloxetine with one selective serotonin reuptake inhibitor (SSRI) (six studies versus paroxetine, three studies versus escitalopram and two versus fluoxetine), four studies (overall 1978 participants) comparing duloxetine with a newer antidepressants (three with venlafaxine and one with desvenlafaxine, respectively) and one study (overall 453 participants) comparing duloxetine with an antipsychotic drug which is also used as an antidepressive agent, quetiapine. No studies were found comparing duloxetine with tricyclic antidepressants. The pooled confidence intervals were rather wide and there were no statistically significant differences in efficacy when comparing duloxetine with other antidepressants. However, when compared with escitalopram or venlafaxine, there was a higher rate of drop out due to any cause in the patients randomised to duloxetine (odds ratio (OR) 1.62; 95% confidence interval (CI) 1.01 to 2.62 and OR 1.56; 95% CI 1.14 to 2.15, respectively). There was also some weak evidence suggesting that patients taking duloxetine experienced more adverse events than paroxetine (OR 1.24; 95% CI 0.99 to 1.55).

AUTHORS' CONCLUSIONS

Duloxetine did not seem to provide a significant advantage in efficacy over other antidepressive agents for the acute-phase treatment of major depression. No differences in terms of efficacy were found, even though duloxetine was worse than some SSRIs (most of all, escitalopram) and newer antidepressants (like venlafaxine) in terms of acceptability and tolerability. Unfortunately, we only found evidence comparing duloxetine with a handful of other active antidepressive agents and only a few trials per comparison were found (in some cases we retrieved just one trial). This limited the power of the review to detect moderate, but clinically meaningful differences between the drugs. As many statistical tests have been used in the review, the findings from this review are better thought of as hypothesis forming rather than hypothesis testing and it would be very comforting to see the conclusions replicated in future trials. Most of included studies were sponsored by the drug industry manufacturing duloxetine. As for all other new investigational compounds, the potential for overestimation of treatment effect due to sponsorship bias should be borne in mind. In the present review no trials reported economic outcomes. Given that several SSRIs and the great majority of antidepressants are now available as generic formulation (only escitalopram, desvenlafaxine and duloxetine are still on patent), more comprehensive economic estimates of antidepressant treatment effect should be considered to better inform healthcare policy.

The safety and tolerability of duloxetine compared with paroxetine and placebo: a pooled analysis of 4 clinical trials

BACKGROUND

To compare the safety and tolerability of duloxetine with paroxetine and placebo in patients with major depressive disorder (MDD).

METHOD

Data from four 8-week randomized, double-blind, placebo- and paroxetine-controlled studies of duloxetine for MDD (DSM-IV criteria) were pooled to compare the safety and tolerability of duloxetine 40 to 120 mg/day with paroxetine 20 mg q.d. Two of the 4 trials included a 26-week extension.

RESULTS

The pooled database included 1466 patients (duloxetine, N = 736; paroxetine, N = 359; placebo, N = 371). No deaths occurred in the acute phase trials. Discontinuation rates for adverse events did not differ significantly for duloxetine, 8.0%, and paroxetine, 6.1%. Nausea was the most frequent treatment-emergent adverse event for duloxetine (duloxetine, 14.4%; paroxetine, 12.0%; placebo, 3.8%). Blood pressure and corrected QT (QTc) interval changes were modest and did not differ significantly for the 3 groups. Mean heart rate increased slightly in the duloxetine group, 1.0 beat/minute, and did differ significantly (p < .001) from that in the paroxetine group, but the change is of doubtful importance. Mean changes in laboratory analytes remained within the reference range. Emergent sexual dysfunction was significantly greater among duloxetine- and paroxetine-treated patients than placebo-treated patients (p = .007 vs. duloxetine and p < .001 vs. paroxetine); however, it was significantly lower in duloxetine-treated patients than in paroxetine-treated patients (46.4% vs. 61.4%; p = .015). During the extension phase, weight gain (≥ 7% of initial body weight) was greater in both active-treatment groups than in the placebo group (duloxetine, 10.8%; paroxetine, 13.8%; placebo, 3.1%), but the active-treatment groups did not differ.

CONCLUSIONS

Duloxetine is safe and well tolerated in patients with MDD, with safety and tolerability comparable to that of paroxetine.

Emerging drugs for osteoarthritis

INTRODUCTION

Osteoarthritis (OA), the most prevalent form of joint disease, affects as much as 13% of the world's population. In the USA, it is the leading cause of disability in people over age 65 and is characterized by progressive cartilage loss, bone remodeling, osteophyte formation and synovial inflammation with resultant joint pain and disability. There are no treatments marketed for structural disease modification; current treatments mainly target symptoms, with > 75% of patients reporting need for additional symptomatic treatment.

AREAS COVERED

Drugs in later development (Phase II - III) for OA pain and joint structural degeneration are reviewed. Topics that are not covered in this article are procedural-based (e.g., arthrocentesis, physical therapy), behavioral-based (e.g., weight loss, pain coping techniques) or device-based (e.g., knee braces, surgical implants) treatments.

EXPERT OPINION

More in-depth understanding of the pathophysiology of the disease, as well as elucidation of the link between clinical symptomatology and structural changes in the joint will likely lead to the development of novel target classes with promising efficacy in the future. Efficacy notwithstanding, there remain significant hurdles to overcome in clinical development of these therapeutics, inherent in the progression pattern of the disease as well as challenges with readouts for both pain and structure modification trials.

Evaluation of efficacy of duloxetine in stress urinary incontinence in women

Objective:

The purpose of this study has been to assess the efficacy of duloxetine, a selective inhibitor of serotonin and norepinephrine reuptake, in the treatment of stress urinary incontinence (SUI) in women.

Materials and Methods:

The study included 50 women aged above 18 years with a predominant symptom of stress urinary incontinence (SUI). The case definition included a predominant symptom of SUI with a weekly incontinence episode frequency (IEF) of seven or greater and a positive cough stress test. All the patients received duloxetine 20 mg twice daily for 12 weeks. The primary outcome variables included the IEF and improvement in quality of life. Paired Student's ‘t’ test was used to analyze changes in IEF.

Results:

The improvement with duloxetine treatment was found in 40 out of 50 patients. Remaining 10 patients did not show any improvement with duloxetine and discontinued the treatment. In 40 patients, the mean baseline IEF was 12.5/week. At the end of three months treatment, IEF was six/week. This shows a statistically significant reduction in the IEF. Also, there was a good improvement in quality of life with 65% of patients in the “very much better” and “much better” categories according to PGI-I scale. In the remaining 10 patients, there was no significant improvement after one month of treatment and patients underwent surgery.

Conclusions:

The findings support duloxetine as a potential treatment for women with stress urinary incontinence.

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.

A double-blind, randomized, placebo-controlled study of the efficacy and safety of duloxetine for the treatment of chronic pain due to osteoarthritis of the knee

OBJECTIVE

To evaluate the efficacy and safety of duloxetine in the treatment of chronic pain due to osteoarthritis of the knee.

METHODS

This was a 13-week, randomized, double-blind, placebo-controlled trial in patients meeting American College of Rheumatology clinical and radiographic criteria for osteoarthritis of the knee. At baseline, patients were required to have a ≥ 4 weekly mean of the 24-hour average pain ratings. Patients were randomized to either duloxetine 60 mg once daily (QD) or placebo. At week 7, the duloxetine dosage was increased, in a blinded fashion, to 120-mg QD in patients reporting < 30% pain reduction. The primary efficacy measure was Brief Pain Inventory (BPI) 24-hour average pain. Secondary efficacy measures included Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC); Clinical Global Impressions of Severity (CGI-S). Safety and tolerability was also assessed.

RESULTS

Of the total (n = 256) patients, 111 (86.7%) in placebo group and 93 (72.7%) in duloxetine group completed the study. Patients treated with duloxetine had significantly (P ≤ 0.001) greater improvement at all time points on BPI average pain and had significantly greater improvement on BPI pain severity ratings (P ≤ 0.05), WOMAC total (P = 0.044) and physical functioning scores (P = 0.016), and CGI-S (P = 0.009) at the study endpoint. Frequency of treatment-emergent nausea, constipation, and hyperhidrosis were significantly higher in the duloxetine group (P ≤ 0.05). Significantly more duloxetine-treated patients discontinued the trial because of adverse events (P = 0.002).

CONCLUSIONS

Treatment with duloxetine 60 mg to 120 mg QD was associated with significant pain reduction and improved function in patients with pain due to osteoarthritis of the knee.

An improved asymmetric synthetic route to a novel triple uptake inhibitor antidepressant (2S,4R,5R)-2-benzhydryl-5-((4-methoxybenzyl)amino)tetrahydro-2H-pyran-4-ol (D-142)

Triple monoamine reuptake inhibitors have been implicated in the development of a new generation of antidepressants with higher efficacy than the currently existing therapies. In this paper, we have developed an alternative efficient synthetic route for triple monoamine reuptake inhibitor D-142 in 18.5% overall yield in 11 steps starting from diphenylmethane. D-142 was developed by us recently. The key step of the present synthetic strategy is the preferential formation of a bromohydrin from olefin via a cis-bromoinum intermediate, which introduced significant efficiency in the overall synthesis. Furthermore, we have developed an efficient way to recycle the optically active intermediate diol back to the desired chiral epoxide.

Treatment patterns associated with Duloxetine and Venlafaxine use for Major Depressive Disorder

BACKGROUND

Duloxetine and venlafaxine extended release (venlafaxine XR) are SNRIs indicated for the treatment of MDD. This study addresses whether duloxetine and venlafaxine XR are interchangeable in their patterns of use with patients who are depressed or are used more selectively based on treatment history, background characteristics, and presenting symptoms.

METHODS

This was a retrospective analysis of an administrative insurance claims database. We studied patients in managed care with major depressive disorder (MDD) treated with duloxetine or venlafaxine XR. Predictors of treatment and cost were assessed using Chi-square and logistic regression analyses of demographics and past-year medication use and comorbidities.

RESULTS

Patients with MDD treated with duloxetine (n = 9,641) versus venlafaxine XR (n = 8,514) tended to be older, slightly more likely to be female, and treated by a psychiatrist (P < 0.0001). In the prior year, more duloxetine patients (vs. venlafaxine XR) received ≥ 3 unique antidepressants (20.8% vs. 16.6%), ≥ 3 unique pain medications (25.5% vs. 15.6%), and had ≥ 8 unique diagnosed comorbid medical and psychiatric conditions (38.6% vs. 29.1%). The prior 6-month total health care costs were $1,731 higher for duloxetine than for venlafaxine XR and declined for both medications in the 6 months after treatment began. Logistic regression analysis revealed that 61% of duloxetine patients and 61% of venlafaxine XR patients were predictable from prior patient and treatment factors.

CONCLUSIONS

Patients with MDD treated with duloxetine tended to have a more complex and costly antecedent clinical presentation compared with venlafaxine XR patients, suggesting that physicians do not use the medications interchangeably.

Long-term safety of duloxetine during open-label compassionate use treatment of patients who completed previous duloxetine clinical trials

PURPOSE

To provide duloxetine for the treatment of major depressive disorder (MDD), generalized anxiety disorder (GAD), fibromyalgia (FM) and diabetic peripheral neuropathic pain (DPNP) to patients who had previously completed a duloxetine clinical study and for whom, in the opinion of the investigator, no effective alternative therapy was available.

METHODS

Adult outpatients who had previously completed a duloxetine study for the treatment of MDD, GAD, DPNP, or FM received duloxetine 30 mg to 120 mg daily up until its local commercial availability. Safety analyses included treatment-emergent adverse events (TEAEs), serious adverse events (SAEs), AEs reported as reason for discontinuation, and vital signs. No efficacy measures were collected.

RESULTS

Of 667 patients enrolled, 282 (42.3%) were still participating at the time the drug was made commercially available in their countries. Most patients had previously participated in a duloxetine MDD study (76.2%); were female (68.1%) and Caucasian (94.9%). The median duration of exposure was 328 days (range 3-1718 days). The most common reasons for discontinuation were patient decision (25.3%), adverse event (8.4%), and lack of efficacy (8.4%). Of the 86 SAEs experienced by 46 patients, most (including one death) were judged by the investigator to be unrelated to duloxetine treatment. The most common TEAEs were in the System Organ Class of gastrointestinal (28.3%), nervous system (28.0%), and psychiatric (25.8%) and were predominantly mild to moderate in severity. Increases of systolic blood pressure (1.9 mm Hg) and pulse rate (2.2 bpm) at endpoint were reported.

CONCLUSION

The safety data from this long-term compassionate use study of duloxetine were consistent with previous experience and revealed no new safety signals.

LIMITATIONS

The limitations include: lack of a control arm, no efficacy data were collected to assess the long-term efficacy, the results may not necessarily generalize to other ethnic groups as most patients were Caucasians, and lack of consistency in regard to duration of exposure at study entry as patients came from different trials with different study designs. CLINICAL TRIAL REGISTRY ID: www.clinicaltrials.gov--NCT00071708.

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

Duloxetine (DLX) is a dual serotonin and norepinephrine reuptake inhibitor that has been recently approved for the treatment of major depressive disorder (MDD). However, little is known about the relationship between DLX plasma levels and clinical response. The aims of this open-label study were 1) to assess clinical outcome and tolerability of DLX by means of clinician and patient assessments and 2) to evaluate the value of plasma DLX levels as predictors of clinical response and tolerability. This was a naturalistic, open-label study of 45 outpatients affected with MDD (16 men and 29 women), who received DLX at doses of 30-120 mg/day and were evaluated at baseline (T0) and after 2, 4 and 12 weeks (T1-3). The assessments included the Hamilton Rating Scales for Depression (HRSD) and Anxiety (HRSA), Clinical Global Impression-Severity (CGI-S), Beck's Depression Inventory (BDI) and a mood visual analogue scale (VAS). Compared with T0, there were significant improvements in HRSD at T1, T2 and T3 (P < 0.001), in HRSA, CGI-S and the self-administered BDI at T2 and T3 (P < 0.001), and in the VAS scores shown at T3 (P = 0.01). DLX treatment was safe and well tolerated. Plasma DLX levels at T2 ranged from 5 to 135 ng/mL (mean +/- SD = 53.56 +/- 39.45) and correlated almost significantly with the DLX dose (r = 0.35; P = 0.069). There was a significant curvilinear quadratic relationship between the improvement of HRSA scores and plasma DLX levels (R(2) = 0.27; P = 0.02). The incidence of anxiety or irritability was associated with the highest plasma levels. Our findings suggest that monitoring plasma DLX levels may be helpful in predicting better treatment responses and tolerability. The present data seem to suggest an optimal anxiolytic efficacy of DLX at intermediate plasma levels.

Profile of adverse events with duloxetine treatment: a pooled analysis of placebo-controlled studies

BACKGROUND

The serotonin and noradrenaline (norepinephrine) reuptake inhibitor duloxetine has been approved in the US and elsewhere for a number of indications, including psychiatric illnesses and chronic pain conditions. Because the patient populations are diverse within these approved indications, and duloxetine is not yet approved for treatment of other conditions, we wanted to determine if adverse event profiles would differ among patients being treated for these various conditions.

OBJECTIVE

To provide detailed information on the adverse events associated with duloxetine and to identify differences in the adverse event profile between treatment indications and patient demographic subgroups.

METHODS

Data were analysed from all placebo-controlled trials of duloxetine completed as of December 2008. The 52 studies included 17,822 patients (duloxetine n = 10,326; placebo n = 7496) with major depressive disorder, generalized anxiety disorder, diabetic peripheral neuropathic pain, fibromyalgia, osteoarthritis knee pain (OAKP), chronic lower back pain and lower urinary tract disorders. The main outcome measures were rates of treatment-emergent adverse events (TEAEs) and adverse events reported as the reason for discontinuation.

RESULTS

The overall TEAE rate was 57.2% for placebo-treated patients and 72.4% for duloxetine-treated patients (p < or = 0.001). Patients with OAKP had the lowest TEAE rate (placebo 36.7% vs duloxetine 50.2%, p < or = 0.01), while patients with fibromyalgia had the highest rate (placebo 80.0% vs duloxetine 89.0%, p < or = 0.001). The most common TEAE for all indications was nausea (placebo 7.2% vs duloxetine 23.4%, p < or = 0.001), which was predominantly mild to moderate in severity. No statistically significant treatment-by-subgroup interactions for age were found between placebo and duloxetine treatment for the most common TEAEs. The rates of duloxetine-associated dry mouth and fatigue were greater in women than in men (13.1% vs 10.4%, interaction p = 0.004; and 9.4% vs 7.6%, interaction p = 0.03, respectively). Duloxetine-associated dry mouth incidence was higher in Caucasians than non-Caucasians (13.2%, 11.0%, interaction p = 0.04).

CONCLUSIONS

Duloxetine treatment is associated with significantly higher rates of common TEAEs versus placebo, regardless of indication or demographic subgroup. Differences across indications are likely to be attributable to the underlying condition rather than duloxetine, as suggested by the similar trends observed in placebo- and duloxetine-treated patients.

The short- and long-term effect of duloxetine on painful physical symptoms in patients with generalized anxiety disorder: results from three clinical trials

Generalized anxiety disorder (GAD) is associated with painful physical symptoms (PPS). These post hoc analyses of previous trial data assessed PPS and their response to duloxetine treatment in GAD patients. Studies 1 and 2 (n=840) were 9- to 10-week efficacy trials; study 3 (n=887) was a relapse prevention trial comprising a 26-week open-label treatment phase and a 26-week double-blind, placebo-controlled treatment continuation phase. Mean baseline visual analog scale scores (VAS, 0-100; n=1727) ranged from 26 to 37 for overall pain, headache, back pain, shoulder pain, interference with daily activities, and time in pain while awake. In studies 1 and 2, improvement on all VAS scores was greater in duloxetine-treated than in placebo-treated patients (p<or=0.01). In study 3, pain symptoms worsened in responders switched to placebo compared with those maintained on duloxetine (p<or=0.02). In conclusion, duloxetine was efficacious in the short- and long-term treatment of PPS, which are common in GAD patients.

Review of Duloxetine and Venlafaxine in Depression

Objectives:

To compare the efficacy and pharmacologic, pharmacokinetic, drug interaction and adverse effect profiles of duloxetine and venlafaxine.

Methods:

A systematic review of the literature pertaining to duloxetine and venlafaxine was conducted using a computer-aided search of MEDLINE and EMBASE for the period January 1988 to May 2008 with the following search terms: venlafaxine and duloxetine and depression, clinical studies, pharmacology, drug interactions, pharmacokinetics, adverse effects, safety, case reports and review articles.

Results:

Duloxetine and venlafaxine have comparable efficacy and share similar pharmacologic profiles but differ somewhat in their pharmacokinetic profiles, drug interactions and adverse effects. Both agents block the reuptake of serotonin and norepinephrine and both are substrates for the cytochrome P450 2D6 isoenzyme; however, duloxetine inhibits these enzymes to a moderate extent, whereas venlafaxine is only a weak inhibitor. Furthermore, duloxetine is more extensively bound to protein than venlafaxine. Venlafaxine is more likely to elevate blood pressure in a dose-related manner. Both duloxetine and venlafaxine have the potential to cause hepatic injury.

Conclusions:

Although venlafaxine and duloxetine have similar efficacy in the treatment of depression, differences in their adverse effects and pharmacokinetic profiles suggest that one agent may be preferred over the other in certain patient groups.

Efficacy of duloxetine in the treatment of generalized anxiety disorder in patients with clinically significant pain symptoms

Anxiety disorders often are accompanied by painful physical symptoms. This report assessed the effectiveness of duloxetine in improving anxiety symptoms, pain severity, and patient functioning in adults diagnosed with generalized anxiety disorder (GAD), who presented with clinically significant pain symptoms. Data were pooled from two multicenter, randomized, double-blind, placebo-controlled clinical studies evaluating the efficacy of duloxetine 60-120 mg once daily compared with placebo in the treatment of GAD. The primary patient population for these analyses was patients with baseline Visual Analog Scale (VAS) overall pain severity score > or =30. Of the 798 randomized patients that had baseline VAS scores, approximately 44.4% of GAD patients were identified as having baseline VAS overall pain severity score > or =30 (duloxetine N=208, placebo N=146). Duloxetine-treated patients had significantly greater improvement compared with placebo-treated patients on anxiety symptoms (measured by Hamilton Anxiety Scale total score), on patient functioning (measured by the Sheehan Disability Scale Global Functional Impairment Score and across all Sheehan Disability Scale domains), and on all VAS pain items. Patients achieving remission at endpoint, and patients with lower scores on the Clinical Global Impression of Improvement and Patient Global Impression of Improvement scales had greater improvement in VAS pain severity scores. These results suggest that in patients with GAD who present with clinically significant pain symptoms, duloxetine is effective in reducing anxiety symptoms, pain severity, and in improving patient functioning.

The role of duloxetine in the treatment of anxiety disorders

Anxiety disorders (ADs) are the most common type of psychiatric disorders, with a mean incidence of 18.1% and a lifetime prevalence of 28.8%. Pharmacologic options studied for treating ADs may include benzodiazepines, tricyclic antidepressants (TCA), selective serotonin reuptake inhibitors (SSRIs), noradrenergic and specific serotonergic drug (NaSSA) and dual-reuptake inhibitors of serotonin and norepinephrine (SNRIs). In this context, the development of SNRIs (venlafaxine and duloxetine) has been particularly useful. As a dual-acting intervention that targets two neurotransmitter systems, these medications would appePar promising for the treatment of ADs. The purpose of this review was to elucidate current facts and views about the role of duloxetine in the treatment of ADs. In February 2007, duloxetine was approved by FDA for the treatment of generalized anxiety disorder (GAD). The results of trials evaluating the use duloxetine in the treatment of GAD are supportive on its efficacy even if further studies on long-term use are needed. Apart from some interesting case reports, no large studies are, to date, present in literature about duloxetine and other ADs such as panic disorder, social anxiety disorder, obsessive-compulsive disorder and post-traumatic stress disorder. Therefore, the clinical efficacy and the relative good tolerability of duloxetine may be further investigated to widen the therapeutic spectrum of ADs.

Clinical evidence for serotonin and norepinephrine reuptake inhibition of duloxetine

Most antidepressants in clinical use are believed to function by enhancing neurotransmission of serotonin [5-hydroxytryptamine (5-HT)] and/or norepinephrine (NE) via inhibition of neurotransmitter reuptake. Agents that affect reuptake of both 5-HT and NE (serotonin-norepinephrine reuptake inhibitors) have been postulated to offer greater efficacy for the treatment of major depressive disorder (MDD). These dual-acting agents also display a broader spectrum of action, including efficacy for MDD and associated painful physical symptoms, diabetic peripheral neuropathic pain, generalized anxiety disorder, and fibromyalgia syndrome. Substantial preclinical evidence shows that duloxetine, an approved drug for the treatment of MDD, generalized anxiety disorder, and the management of diabetic peripheral neuropathic pain, inhibits reuptake of both 5-HT and NE. This paper reviews clinical and neurochemical evidence of duloxetine's effects on 5-HT and NE reuptake inhibition. The clinical evidence supporting duloxetine's effects on NE reuptake inhibition includes indirect measures such as altered excretion of NE metabolites, cardiovascular effects, and treatment-emergent adverse event profiles similar to those for other drugs believed to act through the inhibition of NE reuptake. In summary, the data presented in this report provide clinical evidence of a mechanism for duloxetine involving both 5-HT and NE reuptake inhibition in humans and are consistent with preclinical evidence for 5-HT/NE reuptake inhibition.

A randomized, double-blind comparison of duloxetine and venlafaxine in the treatment of patients with major depressive disorder

BACKGROUND

Clinical trials assessing antidepressant therapies typically include separate assessments of efficacy (benefit) and adverse events (risk). Global benefit-risk (GBR) assessment allows the simultaneous evaluation of both efficacy and adverse events. The objective was to compare the serotonin and norepinephrine reuptake inhibitors (SNRIs) duloxetine and venlafaxine using GBR assessment.

METHODS

Data were combined from two similarly designed, multicenter, randomized, double-blind, parallel group studies in which patients with major depressive disorder were randomized to either duloxetine 60 mg/day or venlafaxine extended release (XR) 150 mg/day (75 mg/day for the first 2 weeks) for a 6-week fixed dosing period followed by an additional 6 weeks of treatment in which the dose could be increased up to 120 mg/day for duloxetine and 225 mg/day for venlafaxine. Patients completing the study (or receiving study drug for 2 weeks or more) were eligible to enter a taper period where the dose of study drug was gradually reduced over 1-2 weeks prior to drug discontinuation. The primary outcome measure (defined a priori) was the GBR comparison of duloxetine 60 mg/day and venlafaxine XR 150 mg/day after 6 weeks of treatment. In the GBR analysis, benefit was defined as remission at endpoint [17-item Hamilton Depression Rating Scale (HAMD17) 7]. Risk was defined by four categories: patients having either no adverse events (AEs), AEs with no severity rating greater than moderate, AEs with at least one severity rating of severe, or having discontinued with a reason of self-reported adverse event (regardless of any AE severity). Additional efficacy measures included HAMD17 total score and subscales, HAMA, CGI-S, and PGI-I. Safety and tolerability were assessed via analysis of reasons for discontinuation, treatment-emergent adverse events (TEAEs), discontinuation-emergent adverse events, and changes in vital signs, weight, and laboratory analytes.

RESULTS

There were no significant differences between duloxetine 60 mg/day and venlafaxine 150 mg/day as measured by GBR assessment at the end of 6 weeks (-1.418 vs. -1.079, P = 0.217) or 12 weeks (-0.349 vs. -0.121, P = 0.440), nor were there significant differences between treatment groups on the majority of efficacy measures. Significantly more venlafaxine-treated patients (74.5%) completed 12 weeks of treatment compared with duloxetine-treated patients (64.8%, P =.006). Nausea was the most common treatment-emergent adverse event (TEAE) for both drugs, and was significantly higher with duloxetine 60 mg/day compared to venlafaxine 150 mg/day during the first 6 weeks of treatment (43.6% vs. 35.0%, P0.05). During the taper period, significantly more venlafaxine-treated patients reported discontinuation-emergent adverse events (DEAEs) than duloxetine-treated patients. From a safety perspective, significantly more venlafaxine-treated patients (n = 4) than duloxetine-treated patients (n=0, P =.047) experienced sustained elevations of systolic blood pressure during the fixed dosing period. Otherwise, there were few significant differences in safety measures found between treatment groups during 6 and 12 weeks of therapy.

CONCLUSIONS

Duloxetine 60 mg/day and venlafaxine XR 150 mg/day have similar benefit-risk profiles on the basis of a comparison utilizing GBR assessment. The implications of the more subtle differences between these drugs, as well as for interpreting the GBR assessment, are discussed.

Duloxetine for the management of diabetic peripheral neuropathic pain: response profile

OBJECTIVE

The current analysis examines the response profile in patients receiving duloxetine for the management of diabetic peripheral neuropathic pain (DPNP).

PATIENTS/DESIGN

Data were pooled from three double-blind, randomized, placebo-controlled 12-week acute therapy trials of patients with DPNP of at least 6 months' duration. Study 1 (N = 457) had treatment groups of duloxetine 20 mg once daily (QD), 60 mg QD, 60 mg twice daily (BID), and placebo; Studies 2 (N = 334) and 3 (N = 348) compared duloxetine 60 mg QD and 60 mg BID with placebo. The primary efficacy measure in each study was the weekly mean score of the 24-hour average pain severity. Treatment response was defined as a 30% reduction in pain severity, although some analyses were repeated using alternative response criteria (50% reduction, or 2-point reduction, in pain severity).

RESULTS

Consistently across the three studies, response rates at endpoint were significantly higher among patients receiving duloxetine (60 mg QD or 60 mg BID) than among those receiving placebo, regardless of the chosen response criterion (30% reduction, 50% reduction, or 2-point reduction in weekly mean of 24-hour average pain severity). The proportion of patients achieving pain relief in the duloxetine treatment groups was significantly greater than that in the placebo group at Week 1 and at all subsequent study visits to the end of acute phase therapy. Using diary data (24-hour average pain severity) from the first 7 days of treatment, the first significant separation from placebo in pain severity reduction for duloxetine 60 mg QD occurred at Day 1 (Study 1), Day 2 (Study 2), and Day 4 (Study 3), while significant separation in response rates first occurred at Day 3 when using pooled data.

CONCLUSIONS

Patients with DPNP receiving duloxetine 60 mg QD or 60 mg BID had significantly higher rates of treatment response, when compared with patients receiving placebo, regardless of the chosen response criterion. Response to duloxetine treatment tended to occur early in therapy.

Triple uptake inhibitors: therapeutic potential in depression and beyond

Drugs that interfere with the uptake and/or metabolism of biogenic amines have been used to treat depression for > 4 decades. Early medications such as tricyclic antidepressants and monoamine oxidase inhibitors are effective but possess many side effects that limit their usefulness. Selective serotonin reuptake inhibitors (SSRIs) or selective noradrenaline reuptake inhibitors (SNRIs) are the results of rational design to find drugs that are as effective as the tricyclic antidepressants, but with more selectivity towards a single monoamine transporter. The SSRI class of drugs, which includes fluoxetine, paroxetine and sertraline, were previously viewed as the agents of choice for treating major depression. Recently, inhibitors of both serotonin and noradrenaline uptake ('dual uptake inhibitors'; SSRI/SNRI such as venlafaxine, duloxetine and milnacipran) have gained acceptance in the market. However, neither the SSRIs nor the SSRI/SNRI are fully satisfactory due to a delayed onset of action, low rate of response and side effect that can affect compliance. An important recent development has been the emergence of the triple uptake inhibitors (SSRI/SNRI/selective dopamine reuptake inhibitor), which inhibit the uptake of all three neurotransmitters that are most closely linked to depression: serotonin, noradrenaline and dopamine. Preclinical studies and clinical trials indicate that a drug inhibiting the uptake of all three of these neurotransmitters could produce a more rapid onset of action and possess greater efficacy than traditional antidepressants. This review discusses the evolution of biogenic amine-based therapies, the emerging strategies involved in the design and synthesis of novel triple uptake inhibitors as antidepressants and the therapeutic potential of triple uptake inhibitors.

An Open-Label 52-Week Clinical Extension Comparing Duloxetine with Routine Care in Patients with Diabetic Peripheral Neuropathic Pain

OBJECTIVE

To assess the safety of duloxetine at a fixed-dose of 60 mg twice daily (BID) for up to 52 weeks, and compare duloxetine with routine care in the management of patients with diabetic peripheral neuropathic pain (DPNP).

DESIGN AND INTERVENTIONS

Patients who completed a 13-week, randomized, double-blind, placebo-controlled acute therapy period were randomly reassigned in a 2:1 ratio to therapy with duloxetine 60 mg BID (N = 197) or routine care (N = 96) for an additional 52 weeks.

PATIENTS

The trial included outpatients > or =18 years of age diagnosed with moderate to severe DPNP caused by type 1 or type 2 diabetes.

RESULTS

Fourteen patients discontinued due to adverse events or death (11 [5.6%] duloxetine- and 3 [3.1%] routine care-treated patients). There were no significant therapy-group differences observed for patients with >/=1 serious adverse event. In total, 110 (55.8%) duloxetine- and 47 (49%) routine care-treated patients had > or =1 treatment-emergent adverse event (TEAE). The TEAE with a significant therapy-group difference, with patients in the duloxetine therapy group experiencing a higher percentage of events, was asthenia (11 [5.6%] duloxetine- vs no routine care-treated patients). Duloxetine did not appear to adversely affect lipid profiles, or nerve or eye function. There were no significant therapy-group differences observed in mean change in systolic blood pressure, weight, or electrocardiogram parameters. Significant therapy-group differences were observed in favor of duloxetine in the SF-36 physical component summary score, and subscale scores of physical functioning, bodily pain, mental health, and vitality.

CONCLUSIONS

The results of this study provide support for the use of duloxetine in the long-term management of DPNP.

Duloxetine in the treatment of major depressive disorder: an open-label study

BACKGROUND

Major depressive disorder (MDD) is a chronic and highly disabling condition. Existing pharmacotherapies produce full remission in only 30% to 40% of treated patients. Antidepressants exhibiting dual reuptake inhibition of both serotonin (5-HT) and norepinephrine (NE) may achieve higher rates of remission compared with those acting upon a single neurotransmitter. In this study, the safety and efficacy of duloxetine, a potent dual reuptake inhibitor of 5-HT and NE, were examined.

METHODS

Patients (N = 533) meeting DSM-IV criteria for MDD received open-label duloxetine (60 mg once a day [QD]) for 12 weeks during the initial phase of a relapse prevention trial. Patients were required to have a 17-item Hamilton Rating Scale for Depression (HAMD17) total score >or=18 and a Clinical Global Impression of Severity (CGI-S) score >or=4 at baseline. Efficacy measures included the HAMD17 total score, HAMD17 subscales, the CGI-S, the Patient Global Impression of Improvement (PGI-I) scale, Visual Analog Scales (VAS) for pain, and the Symptom Questionnaire, Somatic Subscale (SQ-SS). Quality of life was assessed using the Sheehan Disability Scale (SDS) and the Quality of Life in Depression Scale (QLDS). Safety was evaluated by recording spontaneously-reported treatment-emergent adverse events, changes in vital signs and laboratory analytes, and the Patient Global Impression of Sexual Function (PGI-SF) scale.

RESULTS

The rate of discontinuation due to adverse events was 11.3%. Treatment-emergent adverse events reported by >or=10% duloxetine-treated patients were nausea, headache, dry mouth, somnolence, insomnia, and dizziness. Following 12 weeks of open-label duloxetine therapy, significant improvements were observed in all assessed efficacy and quality of life measures. In assessments of depression severity (HAMD17, CGI-S) the magnitude of symptom improvement continued to increase at each study visit, while for painful physical symptoms the onset of improvement was rapid and reached a maximum after 2 to 3 weeks of treatment.

CONCLUSION

In this open-label phase of a relapse prevention study, duloxetine (60 mg QD) was shown to be safe and effective in the treatment of MDD.

Duloxetine for the Management of Diabetic Peripheral Neuropathic Pain: Evaluation of Functional Outcomes

OBJECTIVE

To assess the effectiveness of duloxetine, compared with placebo, on patient-reported health outcomes over a 12-week period, in the management of diabetic peripheral neuropathic pain (DPNP).

METHODS

The results were pooled from three 12-week multicenter, double-blind studies. In study 1 (N = 457), patients with DPNP were randomly assigned to treatment with duloxetine 20 mg once daily (QD), 60 mg QD, 60 mg twice daily (BID), or placebo. In studies 2 (N = 334) and 3 (N = 348), patients with DPNP were randomly assigned to treatment with duloxetine 60 mg QD, 60 mg BID, or placebo. Patient-reported functional outcomes were measured by the Short Form 36 (SF-36), the interference portion of the Brief Pain Inventory (BPI), and EuroQol 5D Health Questionnaire (EQ-5D). Results for all functional outcomes from the intent-to-treat and completer populations are discussed.

RESULTS

In the SF-36 health survey and the BPI interference, duloxetine 60 mg QD and 60 mg BID were significantly superior to placebo in all the domains (P <or= 0.03). In the analysis of the EQ-5D, duloxetine 60 mg QD (P = 0.004) and 60 mg BID (P < 0.001) were significantly better than placebo on all items.

CONCLUSIONS

Acute treatment with duloxetine was associated with significant improvement in functional outcomes in persons with DPNP.

ORIGINAL RESEARCH—PSYCHOLOGY: Changes in Sexual Functioning Associated with Duloxetine, Escitalopram, and Placebo in the Treatment of Patients with Major Depressive Disorder

INTRODUCTION

Depression and antidepressant therapy have been associated with sexual dysfunction in short-term and point-prevalence trials.

AIM

This report describes effects of duloxetine and escitalopram on sexual functioning during acute and long-term treatment of major depressive disorder (MDD).

METHODS

In this 8-month, double-blind, placebo-controlled study, adult outpatients with Diagnostic and Statistical Manual of Mental Disorders, 4th Edition (DSM-IV)-defined MDD were randomized to duloxetine 60 mg/day (N = 273; 173 female), escitalopram 10 mg/day (N = 274; 186 female), or placebo (N = 137; 87 female). After the first 8 weeks of treatment, dose increases were permitted to optimize treatment.

MAIN OUTCOME MEASURE

The 14-item Changes in Sexual Functioning Questionnaire (CSFQ) was used to assess sexual functioning.

RESULTS

Of the 114 patients who did not meet total CSFQ score criteria for global sexual dysfunction at baseline (duloxetine, N = 51; escitalopram, N = 39; placebo, N = 24), the incidence of treatment-emergent sexual dysfunction was significantly higher for escitalopram compared with placebo at 4 and 8 weeks, and significantly higher compared with duloxetine at 4 weeks. At 8 weeks, the incidence of treatment-emergent sexual dysfunction was 17/51 (33.3%) for duloxetine-treated patients; 19/39 (48.7%) for escitalopram-treated patients; and 4/24 (16.7%) for placebo-treated patients (P = 0.01 escitalopram vs. placebo; P = 0.13 duloxetine vs. placebo). After 12 weeks, no significant differences were observed between active drugs. At 8 months, the incidence of treatment-emergent sexual dysfunction was 33.3% for duloxetine, 43.6% for escitalopram, and 25.0% for placebo. Regardless of treatment, patients who achieved remission of MDD showed improvement in global sexual functioning, whereas worsening was observed for patients who did not achieve remission (P < 0.001). Discontinuation rates for sexual side effects did not differ between duloxetine (N = 2) and escitalopram (N = 7) (P = 0.07).

CONCLUSIONS

Short-term treatment demonstrated a higher incidence of treatment-emergent sexual dysfunction with escitalopram compared with duloxetine and placebo. After 12 weeks, there were no statistically significant differences between drugs; however, MDD outcome (regardless of treatment) had a significant impact on improvement in global sexual functioning.

Duloxetine versus escitalopram and placebo: an 8-month, double-blind trial in patients with major depressive disorder

BACKGROUND

Duloxetine and escitalopram were compared in an 8-month, randomized, double-blind, placebo-controlled trial in adult outpatients meeting DSM-IV criteria for major depressive disorder (MDD). The results regarding the primary objective of the study (onset of antidepressant action) have been previously published. The current paper focuses on the longer-term (8-month) comparisons of efficacy and safety between duloxetine and escitalopram.

RESEARCH DESIGN AND METHODS

Upon completion of the 8-week, fixed-dose, placebo-controlled, acute-treatment phase (duloxetine 60 mg/day (n = 273), escitalopram 10 mg/day (n = 274), placebo (n = 137)), patients remaining in the duloxetine (n = 188) and escitalopram (n = 208) groups were eligible for double-blind dose increases (duloxetine to 120 mg/day, escitalopram to 20 mg/day), and placebo non-responders were eligible for double-blind rescue to active drug.

MAIN OUTCOME MEASURES

Efficacy was primarily assessed using the HAMD(17). Safety/tolerability assessments included spontaneously reported adverse events (AEs), overall rates and reasons for discontinuation, laboratory analyses, and vital signs.

RESULTS

Both drugs demonstrated similar remission rates over the course of the study, with the probability of remission reaching 70% (duloxetine) and 75% (escitalopram) at 8 months (p = 0.44). Similar improvement was observed for both duloxetine and escitalopram on efficacy measures with the exception of the sleep subscale of the HAMD(17), wherein escitalopram had a statistically significant advantage over duloxetine in improving sleep. Over the entire 8-month study, discontinuation rates differed significantly for duloxetine (62%) compared with escitalopram (55%; p = 0.02). Rates of discontinuation due to AEs did not differ significantly between duloxetine (12.8%), escitalopram (12.0%), and placebo (10.2%) (p > 0.05 all pairwise comparisons). AEs associated with duloxetine tended to emerge early in treatment (e.g., nausea, dry mouth), whereas AEs associated with escitalopram tended to emerge later in treatment (e.g., diarrhea, weight increase). The incidence of sustained hypertension was similar between drugs (1.5 vs. 1.1% patients for duloxetine and escitalopram, respectively). Statistically significant drug differences were identified in the mean changes from baseline to study endpoint for pulse (+3.05 beats per minute (bpm), duloxetine; -0.89 bpm, escitalopram; p < 0.001) and systolic blood pressure (+3.73 mmHg, duloxetine; +0.31 mmHg, escitalopram; p < 0.05), but not diastolic blood pressure (+0.81 mmHg, duloxetine; -0.24 mmHg, escitalopram; p = 0.27). At 8 months, mean change in weight was significantly higher for escitalopram compared with duloxetine (+0.61 kg, duloxetine; +1.83 kg, escitalopram; p < 0.05), however, the incidence of treatment-emergent abnormal weight gain (> or = 7% increase in weight from baseline) was similar between drugs and was significantly greater for both duloxetine and escitalopram compared with placebo.

LIMITATIONS

Because so few patients on placebo (n = 15), in comparison to duloxetine (n = 104) or escitalopram (n = 123), completed the entire 8-month study, the power to detect a difference between the active treatments and placebo after 8 weeks was significantly decreased and very likely insufficient.

CONCLUSION

Throughout the 8-month study, similar improvement was observed for both duloxetine and escitalopram on most efficacy measures with the exception of the sleep subscale of the HAMD(17). Drug differences were identified in safety/tolerability measures.

Antidepressant-like effects of piperine and its derivative, antiepilepsirine

In the present study, antidepressant-like effects of piperine (PIP) and its derivative, antiepilepsirine (AES), were investigated in two depressive models: forced swimming test (FST) and tail suspension test (TST). To further explore the mechanisms underlying their antidepressant-like activities, the brain monoamine levels and monoamine oxidase A and B (MAO-A and MAO-B) activities were also determined. The research results for the first time indicated that after two weeks of chronic administration, PIP and AES at doses of 10-20 mg/kg significantly reduced the duration of immobility in both FST and TST, without accompanying changes in locomotor activity in the open-field test. But at the dose of 80 mg/kg, the antidepressant activity of both PIP and AES returned to the control level in the TST and FST. In the monoamine assay, chronic AES administration significantly elevated the dopamine level in striatum, hypothalamus and hippocampus, and also increased the serotonin level in the hypothalamus and hippocampus. In contrast, chronic treatment of PIP only enhanced the serotonin level in the hypothalamus and hippocampus but did not influence the dopamine level. Moreover, both PIP and AES showed no effects on level of noradrenaline in these brain regions. The MAO activity assay also indicated that PIP and AES showed a minor MAO inhibitory activity. In the present study, we demonstrated that the antidepressant-like effects of PIP and AES might depend on the augmentation of the neurotransmitter synthesis or the reduction of the neurotransmitter reuptake. Antidepressant properties of PIP were supposed to be mediated via the regulation of serotonergic system, whereas the mechanisms of antidepressant action of AES might be due to its dual regulation of both serotonergic and dopaminergic systems.

A retrospective pooled analysis of duloxetine safety in 23,983 subjects

OBJECTIVE

The safety and tolerability of duloxetine for major depressive disorder (MDD), generalized anxiety disorder (GAD), diabetic peripheral neuropathic pain (DPNP), fibromyalgia, and lower urinary tract disorders (LUTD) (including female stress urinary incontinence [SUI] and other LUTDs) has been established in individual clinical studies. The objective of this manuscript is to characterize the overall safety profile of duloxetine, regardless of indication, based on data from the duloxetine exposures integrated safety database.

RESEARCH DESIGN AND METHODS

The duloxetine exposures integrated safety database was examined using pooled data from 23,983 patients randomized to receive duloxetine in 64 studies for MDD, GAD, DPNP, fibromyalgia, or LUTDs. Evaluated aspects of drug safety included treatment-emergent adverse events (TEAEs), adverse events leading to discontinuation, serious adverse events (SAEs), clinical laboratory tests, vital signs, and electrocardiograms.

RESULTS

Common TEAEs included nausea, headache, dry mouth, insomnia, constipation, dizziness, fatigue, somnolence, diarrhea, and hyperhidrosis. Most TEAEs emerged early; the majority were mild to moderate in severity, and did not worsen. Overall, discontinuation rates due to AEs were 20.0%. SAEs occurred at a rate of 3.5% and no single event was predominant. Mean pulse increased by < 2 beats per minute. Mean increases in systolic and diastolic blood pressure were < 1 mmHg. Mean alanine transaminase and aspartate transaminase values increased by < 2 U/L.

CONCLUSIONS

The safety profile for the molecule from the overall duloxetine exposures integrated safety database suggests that benign and common pharmacologic side effects occur with duloxetine treatment. Because these pooled analyses do not allow for statistical comparison to placebo or active comparator, and include data from five different studied indications, these data do not suggest causality for AEs, nor are they necessarily generalizable to each disease stated studied.

Efficacy of duloxetine in painful symptoms: an analgesic or antidepressant effect?

The evidence that the effects of the antidepressant duloxetine on painful physical symptoms in depression and chronic pain disorders are a direct analgesic effect rather than an indirect antidepressant effect is reviewed. Data from placebo-controlled acute studies of duloxetine in major depressive disorder, diabetic peripheral neuropathic pain and fibromyalgia syndrome are included in this review. In placebo-controlled studies of duloxetine in patients with major depressive disorder, non-depressed diabetic peripheral neuropathic pain, and fibromyalgia syndrome, duloxetine has a statistically significantly greater effect on pain than placebo. Path analysis suggests that in these patient populations, approximately 50, 90, and 80%, respectively, of the observed effect on pain is a direct analgesic effect rather than an indirect antidepressant effect. In fibromyalgia syndrome studies, duloxetine had similar and substantial effects on pain regardless of whether patients had comorbid major depressive disorder. Pain is a complex experience, involving both the physiological responses of the nociceptive system and the processing of that information in brain regions associated with emotion. While some effects of duloxetine on painful symptoms can be accounted for by its antidepressant action, the data strongly suggest that duloxetine also exerts a substantial direct analgesic effect over and above its antidepressant effects, in patients with major depressive disorder, diabetic peripheral neuropathic pain, and fibromyalgia syndrome.