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

Analgesic efficacy and safety of duloxetine premedication in patients undergoing hysterectomy - A systematic review

Background and Aims

Patients undergoing hysterectomy by open or laparoscopic approach experience moderate to severe postoperative pain. A multimodal analgesic approach is recommended for these patients. This study reviews the analgesic efficacy of duloxetine, a selective serotonin and norepinephrine reuptake inhibitor used as an adjuvant for opioid-sparing postoperative analgesia.

Methods

After registering the protocol in the international prospective register of systematic reviews (PROSPERO), databases like PubMed, Ovid, Scopus, Cochrane Library and clinicaltrials.gov were searched for randomised controlled trials using relevant keywords to find studies in which duloxetine premedication was compared to a placebo in patients undergoing hysterectomy. The revised Cochrane risk-of-bias tool for randomised trials (RoB 2) was used to assess the quality of evidence.

Results

The qualitative systematic review included five of the 88 studies identified. The overall risk of bias in the included studies was very high. In all the studies, 60 mg oral duloxetine was used, and the control group was placebo. In two studies, duloxetine premedication was administered 2 h before and 24 h after surgery. In the other three studies, a single dose of 60 mg duloxetine was only administered 2 h before surgery. A pooled meta-analysis was not performed due to fewer studies that fulfilled the inclusion criteria and even fewer studies with consistent reporting of various outcomes.

Conclusion

The evidence is insufficient to advocate routine duloxetine premedication in patients undergoing hysterectomy.

Antidepressants for hip and knee osteoarthritis

BACKGROUND

Although pain is common in osteoarthritis, most people fail to achieve adequate analgesia. Increasing acknowledgement of the contribution of pain sensitisation has resulted in the investigation of medications affecting pain processing with central effects. Antidepressants contribute to pain management in other conditions where pain sensitisation is present.

OBJECTIVES

To assess the benefits and harms of antidepressants for the treatment of symptomatic knee and hip osteoarthritis in adults.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search was January 2021.

SELECTION CRITERIA

We included randomised controlled trials of adults with osteoarthritis that compared use of antidepressants to placebo or alternative comparator. We included trials that focused on efficacy (pain and function), treatment-related adverse effects and had documentation regarding discontinuation of participants. We excluded trials of less than six weeks of duration or had participants with concurrent mental health disorders.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Major outcomes were pain; responder rate; physical function; quality of life; and proportion of participants who withdrew due to adverse events, experienced any adverse events or had serious adverse events. Minor outcomes were proportion meeting the OARSI (Osteoarthritis Research Society International) Response Criteria, radiographic joint structure changes and proportion of participants who dropped out of the study for any reason. We used GRADE to assess certainty of evidence.

MAIN RESULTS

Nine trials (2122 participants) met the inclusion criteria. Seven trials examined only knee osteoarthritis. Two also included participants with hip osteoarthritis. All trials compared antidepressants to placebo, with or without non-steroidal anti-inflammatory drugs. Trial sizes were 36 to 388 participants. Most participants were female, with mean ages of 54.5 to 65.9 years. Trial durations were 8 to 16 weeks. Six trials examined duloxetine. We combined data from nine trials in meta-analyses for knee and hip osteoarthritis. One trial was at low risk of bias in all domains. Five trials were at risk of attrition and reporting bias. High-certainty evidence found that antidepressants resulted in a clinically unimportant improvement in pain compared to placebo. Mean reduction in pain (0 to 10 scale, 0 = no pain) was 1.7 points with placebo and 2.3 points with antidepressants (mean difference (MD) -0.59, 95% confidence interval (CI) -0.88 to -0.31; 9 trials, 2122 participants). Clinical response was defined as achieving a 50% or greater reduction in 24-hour mean pain. High-certainty evidence demonstrated that 45% of participants receiving antidepressants had a clinical response compared to 28.6% receiving placebo (RR 1.55, 95% CI 1.32 to 1.82; 6 RCTs, 1904 participants). This corresponded to an absolute improvement in pain of 16% more responders with antidepressants (8.9% more to 26% more) and a number needed to treat for an additional beneficial effect (NNTB) of 6 (95% CI 4 to 11). High-certainty evidence showed that the mean improvement in function (on 0 to 100 Western Ontario and McMaster Universities Arthritis Index, 0 = best function) was 10.51 points with placebo and 16.16 points with antidepressants (MD -5.65 points, 95% CI -7.08 to -4.23; 6 RCTs, 1909 participants). This demonstrates a small, clinically unimportant response. Moderate-certainty evidence (downgraded for imprecision) showed that quality of life measured using the EuroQol 5-Dimension scale (-0.11 to 1.0, 1.0 = perfect health) improved by 0.07 points with placebo and 0.11 points with antidepressants (MD 0.04, 95% CI 0.01 to 0.07; 3 RCTs, 815 participants). This is clinically unimportant. High-certainty evidence showed that total adverse events increased in the antidepressant group (64%) compared to the placebo group (49%) (RR 1.27, 95% CI 1.15 to 1.41; 9 RCTs, 2102 participants). The number needed to treat for an additional harmful outcome (NNTH) was 7 (95% CI 5 to 11). Low-certainty evidence (downgraded twice for imprecision for very low numbers of events) found no evidence of a difference in serious adverse events between groups (RR 0.94, 95% CI 0.46 to 1.94; 9 RCTs, 2101 participants). The NNTH was 1000.  Moderate-certainty evidence (downgraded for imprecision) showed that 11% of participants receiving antidepressants withdrew from trials due to an adverse event compared to 5% receiving placebo (RR 2.15, 95% CI 1.56 to 2.97; 6 RCTs, 1977 participants). The NNTH was 17 (95% CI 10 to 35).

AUTHORS' CONCLUSIONS

There is high-certainty evidence that use of antidepressants for knee osteoarthritis leads to a non-clinically important improvement in mean pain and function. However, a small number of people will have a 50% or greater important improvement in pain and function. This finding was consistent across all trials. Pain in osteoarthritis may be due to a variety of causes that differ between individuals. It may be that the cause of pain that responds to this therapy is only present in a small number of people. There is moderate-certainty evidence that antidepressants have a small positive effect on quality of life with heterogeneity between trials. High-certainty evidence indicates antidepressants result in more adverse events and moderate-certainty evidence indicates more withdrawal due to adverse events. There was little to no difference in serious adverse events (low-certainty evidence due to low numbers of events). This suggests that if antidepressants were being considered, there needs to be careful patient selection to optimise clinical benefit given the known propensity for adverse events with antidepressant use. Future trials should include alternative antidepressant agents or phenotyping of pain in people with osteoarthritis, or both.

Duloxetine overdose causes sympathomimetic and serotonin toxicity without major complications

OBJECTIVE

Duloxetine is a commonly used antidepressant that is a serotonin and norepinephrine reuptake inhibitor. We aimed to investigate the frequency and severity of clinical effects following duloxetine overdose.

METHODS

We undertook a retrospective review of duloxetine overdoses (>120 mg) admitted to two tertiary toxicology units between March 2007 and May 2021. Demographic information, details of ingestion (dose, co-ingestants), clinical effects, investigations (ECG parameters including QT interval), complications (coma [GCS < 9], serotonin toxicity, seizures and cardiovascular effects), length of stay [LOS] and intensive care unit [ICU] admission were extracted from a clinical database.

RESULTS

There were 241 duloxetine overdoses (>120 mg), median age 37 years (interquartile range [IQR]: 25-48 years) and there were 156 females (65%). The median dose was 735 mg (IQR: 405-1200 mg). In 177 patients, other medications were co-ingested, most commonly alcohol, paracetamol, quetiapine, diazepam, ibuprofen, pregabalin and oxycodone. These patients were more likely to be admitted to ICU (12 [7%] vs. none; p = 0.040), develop coma (16 [9%] vs. none; p = 0.008) and hypotension [systolic BP < 90 mmHg] (15 [8%] vs. one; p = 0.076). Sixty four patients ingested duloxetine alone with a median dose of 840 mg (180-4200 mg). The median LOS, in the duloxetine only group, was 13 h (IQR:8.3-18 h), which was significantly shorter than those taking coingestants, 19 h (IQR:12-31 h; p = 0.004). None of these patients were intubated. Six patients developed moderate serotonin toxicity, without complications and one had a single seizure. Tachycardia occurred in 31 patients (48%) and mild hypertension (systolic BP > 140 mmHg) in 29 (45%). One patient had persistent sympathomimetic toxicity, and one had hypotension after droperidol. Two patients of 63 with an ECG recorded had an abnormal QT: one QT 500 ms, HR 46 bpm, which resolved over 3.5 h and a second with tachycardia (QT 360 ms, HR 119 bpm). None of the 64 patients had an arrhythmia.

CONCLUSION

Duloxetine overdose most commonly caused sympathomimetic effects and serotonin toxicity, consistent with its pharmacology, and did not result in coma, arrhythmias or intensive care admission, when taken alone in overdose.

The Treatment of Painful Diabetic Neuropathy

Painful diabetic peripheral neuropathy (painful-DPN) is a highly prevalent and disabling condition, affecting up to one-third of patients with diabetes. This condition can have a profound impact resulting in a poor quality of life, disruption of employment, impaired sleep, and poor mental health with an excess of depression and anxiety. The management of painful-DPN poses a great challenge. Unfortunately, currently there are no Food and Drug Administration (USA) approved disease-modifying treatments for diabetic peripheral neuropathy (DPN) as trials of putative pathogenetic treatments have failed at phase 3 clinical trial stage. Therefore, the focus of managing painful- DPN other than improving glycaemic control and cardiovascular risk factor modification is treating symptoms. The recommended treatments based on expert international consensus for painful- DPN have remained essentially unchanged for the last decade. Both the serotonin re-uptake inhibitor (SNRI) duloxetine and α2δ ligand pregabalin have the most robust evidence for treating painful-DPN. The weak opioids (e.g. tapentadol and tramadol, both of which have an SNRI effect), tricyclic antidepressants such as amitriptyline and α2δ ligand gabapentin are also widely recommended and prescribed agents. Opioids (except tramadol and tapentadol), should be prescribed with caution in view of the lack of definitive data surrounding efficacy, concerns surrounding addiction and adverse events. Recently, emerging therapies have gained local licenses, including the α2δ ligand mirogabalin (Japan) and the high dose 8% capsaicin patch (FDA and Europe). The management of refractory painful-DPN is difficult; specialist pain services may offer off-label therapies (e.g. botulinum toxin, intravenous lidocaine and spinal cord stimulation), although there is limited clinical trial evidence supporting their use. Additionally, despite combination therapy being commonly used clinically, there is little evidence supporting this practise. There is a need for further clinical trials to assess novel therapeutic agents, optimal combination therapy and existing agents to determine which are the most effective for the treatment of painful-DPN. This article reviews the evidence for the treatment of painful-DPN, including emerging treatment strategies such as novel compounds and stratification of patients according to individual characteristics (e.g. pain phenotype, neuroimaging and genotype) to improve treatment responses.

Pharmacological Management of Osteoarthritis With a Focus on Symptomatic Slow-Acting Drugs: Recommendations From Leading Russian Experts

BACKGROUND

This article describes an updated stepwise algorithm for the pharmacological management of osteoarthritis (OA) to establish a treatment method for patients with OA.

SUMMARY

In step 1, background maintenance therapy includes symptomatic slow-acting drugs for OA, especially prescription crystalline glucosamine sulfate product, for which the high-quality evidence base of efficacy is unequivocal, or prescription chondroitin sulfate. Oral nonsteroidal anti-inflammatory drugs (NSAIDs) or paracetamol only as rescue analgesia is given on top of the background therapy. Step 2: For patients with persistent OA symptoms, the use of oral NSAIDs is mandatory for maintaining supportive therapy with symptomatic slow-acting drugs for OA. It is recommended to properly stratify patients and carefully select oral NSAID therapy to maximize the benefit-to-risk ratio. Intra-articular hyaluronic acid and intra-articular corticosteroids are recommended as well in step 2 of the algorithm, especially for patients who do not respond to the previous therapies. Step 3: Duloxetine is considered along with the previous procedures, especially in patients with pain from central sensitization. Step 4: Total joint replacement is recommended for patients with severe symptoms and poor quality of life.

MAJOR CONCLUSIONS

The current guidelines and literature review provide evidence-based recommendations supported by clinical experience on how to organize the treatment process in patients with knee OA applicable in the Russian clinical practice.

FUTURE RESEARCH DIRECTIONS

International evidence-based guidelines lack consensus on different treatments, including the use of prescription crystalline glucosamine sulfate, NSAIDs, and intra-articular hyaluronic acid. The content of this article needs a further discussion about the clinical evidence and harmonization of recommendations for knee OA management.

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.

Green Light Exposure Improves Pain and Quality of Life in Fibromyalgia Patients: A Preliminary One-Way Crossover Clinical Trial

OBJECTIVE

Fibromyalgia is a functional pain disorder in which patients suffer from widespread pain and poor quality of life. Fibromyalgia pain and its impact on quality of life are not effectively managed with current therapeutics. Previously, in a preclinical rat study, we demonstrated that exposure to green light-emitting diodes (GLED) for 8 hours/day for 5 days resulted in antinociception and reversal of thermal and mechanical hypersensitivity associated with models of injury-related pain. Given the safety of GLED and the ease of its use, our objective is to administer GLED as a potential therapy to patients with fibromyalgia.

DESIGN

One-way crossover clinical trial.

SETTING

United States.

METHOD

We enrolled 21 adult patients with fibromyalgia recruited from the University of Arizona chronic pain clinic who were initially exposed to white light-emitting diodes and then were crossed over to GLED for 1 to 2 hours daily for 10 weeks. Data were collected by using paper surveys.

RESULTS

When patients were exposed to GLED, but not white light-emitting diodes, they reported a significant reduction in average pain intensity on the 10-point numeric pain scale. Secondary outcomes were assessed by using the EQ-5D-5L survey, Short-Form McGill Pain Questionnaire, and Fibromyalgia Impact Questionnaire and were also significantly improved in patients exposed to GLED. GLED therapy was not associated with any measured side effects in these patients.

CONCLUSION

Although the mechanism by which GLED elicits pain reduction is currently being studied, these results supporting its efficacy and safety merit a larger clinical trial.

Therapeutic Potential of Polyphenols in the Management of Diabetic Neuropathy

Diabetic neuropathy (DN) is a common and serious diabetes-associated complication that primarily takes place because of neuronal dysfunction in patients with diabetes. Use of current therapeutic agents in DN treatment is quite challenging because of their severe adverse effects. Therefore, there is an increased need of identifying new safe and effective therapeutic agents. DN complications are associated with poor glycemic control and metabolic imbalances, primarily oxidative stress (OS) and inflammation. Various mediators and signaling pathways such as glutamate pathway, activation of channels, trophic factors, inflammation, OS, advanced glycation end products, and polyol pathway have a significant contribution to the progression and pathogenesis of DN. It has been indicated that polyphenols have the potential to affect DN pathogenesis and could be used as potential alternative therapy. Several polyphenols including kolaviron, resveratrol, naringenin, quercetin, kaempferol, and curcumin have been administered in patients with DN. Furthermore, chlorogenic acid can provide protection against glutamate neurotoxicity via its hydrolysate, caffeoyl acid group, and caffeic acid through regulating the entry of calcium into neurons. Epigallocatechin-3-gallate treatment can protect motor neurons by regulating the glutamate level. It has been demonstrated that these polyphenols can be promising in combating DN-associated damaging pathways. In this article, we have summarized DN-associated metabolic pathways and clinical manifestations. Finally, we have also focused on the roles of polyphenols in the treatment of DN.

Oral pharmacotherapeutics for the management of peripheral neuropathic pain conditions - a review of clinical trials

INTRODUCTION

Epidemiological studies have shown that 6.9-10% of people suffer from neuropathic pain, a complex painful condition which is often undertreated. Data regarding the effectiveness of treatment options for patients with neuropathic pain is inconsistent, and there is no single treatment option that shows cost-effectiveness across studies.

AREAS COVERED

In this narrative review, the authors present the results of different prospective, randomized controlled trials, systematic reviews and meta-analyses assessing the effects of different oral medications in the management of various peripheral neuropathic pain conditions. The authors discuss the effectiveness of commonly used oral medications such as voltage-gated calcium channels antagonists, voltage-gated sodium channel antagonists, serotonin-norepinephrine reuptake inhibitors, NMDA antagonists, and medications with other mechanisms of action.

EXPERT OPINION

Most of the presented medications were more effective than placebo; however, when compared to each other, none of them were significantly superior. The heterogeneity of the studies looking into different oral neuropathic conditions has been the major issue that prevents us from making stronger recommendations. There are multiple reasons including high placebo responsiveness, improperly treated underlying comorbidities (particularly anxiety and depression), and inter-patient variability. Different sensory phenotypes should also be taken into consideration when designing future clinical trials for neuropathic pain.

Efficacy and safety of duloxetine in osteoarthritis or chronic low back pain: a Systematic review and meta-analysis

OBJECTIVE

To evaluate the efficacy and safety of duloxetine in the treatment of patients with osteoarthritis (OA) or chronic low back pain (CLBP).

METHODS

Relevant randomized controlled trials (RCTs) were searched in PubMed, Embase, Web of Science, Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov. Included RCTs compared the efficacy and safety of duloxetine vs placebo in the treatment of OA or CLBP. Weighted mean difference (WMD) were calculated for continuous outcomes while risk ratio (RR) were calculated for dichotomous outcomes.

RESULTS

Nine RCTs were included in our meta-analysis. Duloxetine had significant improvement over placebo in Brief Pain Inventory 24-h average pain [WMD: -0.67; 95% confidence interval (CI):-0.80, -0.53], weekly mean of the 24-h average pain (WMD: -0.65; 95% CI: -0.79, -0.52), Patient's Global Impression of Improvement (WMD: -0.41; 95% CI: -0.49, -0.32), Clinical Global Impression of Severity (WMD: -0.32; 95% CI: -0.38, -0.25), European Quality of Life Questionnaire-5 Dimension (WMD: 0.04; 95% CI: 0.02, 0.07). In addition, duloxetine is associated with more treatment-emergent adverse events (TEAEs) (RR: 1.25; 95% CI: 1.17, 1.33) and discontinuations for adverse events (AEs) (RR: 2.31; 95% CI: 1.81, 2.94). However, there was no statistically significant difference in serious AEs between duloxetine and placebo.

CONCLUSION

Duloxetine had modest to moderate effects on pain relief, function improvement, mood regulation and improvement in quality of life with mild AEs in the treatment of OA or CLBP. Future RCTs should focus on comparing duloxetine with other oral drugs and assessing the long-term safety of duloxetine.

The short-term effect and safety of duloxetine in osteoarthritis: A systematic review and meta-analysis

BACKGROUND

Previous clinical trials indicated that duloxetine may be effective in the treatment of osteoarthritis (OA) pain. This meta-analysis is conducted to evaluate short term analgesic effect and safety of duloxetine in the treatment of OA.

METHODS

Electronic databases were searched in February 2019, including PUBMED, EMBASE, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, Web of Science. All eligible studies should be randomized controlled trials (RCTs) comparing duloxetine treatment group to placebo about OA pain relief and safety outcomes.

RESULTS

Five RCTs with 2059 patients were involved in this systematic review and meta-analysis. Compared to placebo, duloxetine treatment showed significant better result, with higher reduction pain intensity (mean difference [MD] = -0.77, P < .00001), higher rates of both 30% and 50% reduction in pain severity (risk ratio [RR] = 1.42, P < .00001; RR = 1.62, P < .00001), lower mean Patient Global Improvement-Inventory (PGI-I) score (MD = -0.48, P < .00001). The results of the Western Ontario and McMaster Universities (WOMAC) score change from baseline to endpoint also favored duloxetine treatment group in all four categories, including total (MD = -5.43, P < .00001), pain (MD = -1.63, P = .001), physical function (MD = -4.22, P < .00001), and stiffness score (MD = -0.58, P < .00001). There were higher rates of treatment-emergent adverse events (TEAEs) (RR = 1.32, P < .00001) and discontinuation (RR = 1.88, P < .00001) in duloxetine group. However, there was no significant difference in the incidence of severe adverse events (SAEs) between these 2 groups (RR = 0.84, P = .68).

CONCLUSION

Duloxetine was an effective and safe choice to improve pain and functional outcome in OA patients. However, further studies are still needed to find out the optimal dosage for OA and examine its long-term efficacy and safety.

TRIAL REGISTRATION NUMBER

CRD42019128862.

Maintenance of effect of duloxetine in Chinese patients with pain due to osteoarthritis: 13-week open-label extension data

Background

The objectives of this study were to assess the maintenance of effect of duloxetine 60 mg once-daily (QD) in Chinese patients with chronic pain due to osteoarthritis (OA) of the knee or hip and to provide additional long-term safety data.

Methods

This was an open-label, extension phase of a randomized, double-blind, placebo-controlled clinical trial. Eligible patients were outpatients who met the American College of Rheumatology clinical and radiographic criteria for OA with a rating ≥4 on Brief Pain Inventory (BPI) 24-h average pain. After completing the 13-week placebo-controlled phase, patients originally assigned to placebo were titrated to duloxetine 60 mg QD (PLA_DLX), whereas patients originally assigned to duloxetine 60 mg QD remained on the same dose of duloxetine (DLX_DLX) for another 13 weeks. The maintenance effect of duloxetine 60 mg QD during the extension phase was evaluated by a 1-sided 97.5% confidence interval (CI) of the baseline-to-endpoint change in the extension phase for patients who took duloxetine and reported ≥30% reduction in BPI average pain at the end of placebo-controlled phase (placebo-controlled phase duloxetine responders). Other BPI severity and interference items, as well as safety and tolerability, were assessed.

Results

Of 342 patients entering the extension phase, 162 (97.6%) DLX_DLX-treated patients and 157 (89.2%) PLA_DLX-treated patients completed this phase. Most patients (76.0%) were female. Mean age was 60.6 years. Mean BPI average pain was 5.5 at baseline of the placebo-controlled phase. Among 113 placebo-controlled phase duloxetine responders, mean change in BPI average pain during the extension phase was − 0.59 (from 2.47 to 1.88); the upper bound of the 1-sided 97.5% CI was − 0.31 and less than the pre-specified non-inferiority margin of a 1.5-point increase (p < 0.001). Significant within-group improvements in all BPI items were observed for both PLA_DLX and DLX_DLX groups during the extension phase (all p < 0.01). No deaths or suicide-related events occurred. Seven (4.0%) PLA_DLX-treated patients and no DLX_DLX-treated patients discontinued due to an adverse event.

Conclusion

The analgesic effect of duloxetine 60 mg QD among treatment responders was maintained for the entire duration of the extension phase. Duloxetine 60 mg QD was well tolerated during the extension phase.

Trial registration

ClinicalTrials.gov identification number NCT01931475. Registered 29 August 2013.

Mirogabalin and emerging therapies for diabetic neuropathy

There are currently no approved disease-modifying therapies for diabetic neuropathy, and there are only 3 US Food and Drug Administration-approved therapies (pregabalin, duloxetine, and tapentadol) for painful diabetic neuropathy. They each have moderate efficacy with adverse effects limiting optimal dose titration. There is a considerable need for new therapies for the management of painful diabetic neuropathy. We reviewed the potential role of mirogabalin, which like gabapentin and pregabalin modulates the alpha-2/delta-1 subunit of the voltage-gated calcium channel, allowing the influx of calcium and release of neurotransmitters at the synaptic cleft in the central nervous system and spinal cord. It has shown efficacy and good tolerability in a Phase II study in diabetic painful neuropathy and based on the results of two Phase III clinical trials in diabetic painful neuropathy and post-herpetic neuralgia, Daiichi Sankyo submitted a marketing application for neuropathic pain in Japan in February 2018. We have also reviewed potential new therapies, currently in Phase II clinical trials that may modify disease and/or relieve neuropathic pain through novel modes of action.

Temporal Profiles and Dose-Responsiveness of Side Effects with Escitalopram and Duloxetine in Treatment-Naïve Depressed Adults

Side effect profiles of antidepressants are relevant to treatment selection and adherence among patients with major depressive disorder (MDD), but several clinically-relevant characteristics of side effects are poorly understood. We aimed to compare the side effect profiles of escitalopram and duloxetine, including frequencies, time to onset, duration, dose responsiveness, and impact on treatment outcomes. Side effects occurring in 211 treatment-naïve patients with MDD randomized to 12 weeks of treatment with flexibly-dosed escitalopram (10–20 mg/day) or duloxetine (30–60 mg/day) as part of the Predictors of Remission in Depression to Individual and Combined Treatments (PReDICT) study were evaluated. Escitalopram- and duloxetine-treated patients experienced a similar mean number of overall side effects and did not differ in terms of the specific side effects observed or their temporal profile. Experiencing any side effect during the first 2 weeks of treatment was associated with increased likelihood of trial completion (86.7% vs. 73.7%, p = 0.045). Duloxetine-treated patients who experienced dry mouth were significantly more likely to achieve remission than those who did not (73.7% vs. 44.8%, p = 0.026). Side effects that resolved prior to a dose increase were unlikely to recur after the increase, but only about 45% of intolerable side effects that required a dose reduction resolved within 30 days of the reduction. At the doses used in this study, escitalopram and duloxetine have similar side effect profiles. Understanding characteristics of side effects beyond simple frequency rates may help prescribers make more informed medication decisions and support conversations with patients to improve treatment adherence.

Study of Sex Differences in Duloxetine Efficacy for Depression in Transgenic Mouse Models

Clinical evidences show sex differences in risk of developing depressive disorders as well as effect of antidepressants in depression treatment. However, whether such a sex-dependent risk of depression and efficacy of antidepressants is dependent on endogenous estrogen level remain elusive. The aim of this study is to explore the molecular mechanisms of sex differences in antidepressant duloxetine. In the present study, we used genetic knockout or overexpression estrogen-synthesizing enzyme aromatase (Ar) gene as models for endogenous estrogen deficiency and elevation endogenous estrogen, respectively, to examine the anti-depressive efficacy of duloxetine in males and females by force swimming test (FST). We also measured the sex-specific effect of duloxetine on dopamine and serotonin (5-HT) metabolisms in frontal cortex and hippocampus (HPC). Elevation of brain endogenous estrogen in male and female mice showed a reduction of immobility time in FST compared to control mice. Estrogen deficiency in females showed poor response to duloxetine treatment compared to sex-matched wildtype (WT) or aromatase transgenic mice. In contrast, male mice with estrogen deficiency showed same anti-depressive response to duloxetine treatments as aromatase transgenic mice. Our data showed that the sex different effect of endogenous estrogen on duloxetine-induced anti-depressive behavioral change is associated with brain region-specific changes of dopamine (DA) and 5-HT system. Endogenous estrogen exerts antidepressant effects in both males and females. Lacking of endogenous estrogen reduced antidepressive effect of duloxetine in females only. The endogenous estrogen level alters 5-HT system in female mainly, while both DA and 5-HT metabolisms were regulated by endogenous estrogen levels after duloxetine administration.

Treatment discontinuation and tolerability as a function of dose and titration of duloxetine in the treatment of major depressive disorder

PURPOSE

We sought to better understand how dose and titration with duloxetine treatment may impact tolerability and treatment discontinuation in patients with major depressive disorder.

PATIENTS AND METHODS

We investigated Phase III duloxetine trials. Group 1 was a single placebo-controlled study with a 20 mg initial dose and a slow titration to 40 and 60 mg. Group 2 was a single study with a 40 mg initial dose and final "active" doses of 40 and 60 mg (5 mg control group), with 1-week titration. Group 3 consisted of eight placebo-controlled studies with starting doses of 40, 60, and 80 mg/day with minimal titration (final dose 40-120 mg/day). Tolerability was measured by rate of discontinuation due to adverse events (DCAE).

RESULTS

The DCAE in Group 1 were 3.6% in the 60 mg group, 3.3% in the 40 mg group, and 3.2% in the placebo group. In Group 2, the DCAE were 15.0% in the 60 mg group, 8.1% in the 40 mg group, and 4.9% in the 5 mg group. In Group 3, the DCAE were 9.7% and 4.2% in the duloxetine and placebo groups, respectively.

CONCLUSION

This study suggests that starting dose and titration may have impacted tolerability and treatment discontinuation. A lower starting dose of duloxetine and slower titration may contribute to improving treatment tolerability for patients with major depressive disorder.

A Mechanism-Based Approach to the Management of Osteoarthritis Pain

Pain from osteoarthritis (OA) affects millions of people worldwide, yet treatments are limited to acetaminophen, NSAIDs, physical therapy, and ultimately, surgery when there is significant disability. In recent years, our understanding of pain pathways in OA has developed considerably. Though joint damage and inflammation play a significant role in pain generation, it is now understood that both central and peripheral nervous system mechanisms exacerbate symptoms. Evolving management strategies for OA address central factors (e.g., sleep difficulties, catastrophizing, and depression) with treatments such as cognitive behavioral therapy and exercise. In addition, emerging data suggest that antibodies against peripheral signaling neuropeptides, such as nerve growth factor-1 (NGF-1), may significantly alleviate pain. However, concerns regarding potential adverse effects, such as rapidly progressive OA, still remain. A nuanced understanding is essential if we are to make headway in developing more effective treatments for OA.

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.

Acute and longer-term safety results from a pooled analysis of duloxetine studies for the treatment of children and adolescents with major depressive disorder

OBJECTIVE

To assess acute and longer-term safety of duloxetine in the treatment of children and adolescents with major depressive disorder (MDD), a pooled analysis of data from two completed randomized, double-blind, multicenter, phase 3, placebo- and active-controlled trials was undertaken. In these studies, neither duloxetine (investigational drug) nor fluoxetine (active control) demonstrated a statistically significant improvement compared with placebo on the primary efficacy measure.

METHODS

Patients ages 7-17 years with MDD as defined by the Diagnostic and Statistical Manual of Mental Disorders, 4th ed., Text Revision (DSM-IV-TR) received duloxetine (n=341), fluoxetine (n=234), or placebo (n=225) for 10 week acute and 26 week extended (duloxetine or fluoxetine only) treatments. Safety measures included treatment-emergent adverse events (TEAEs), the Columbia-Suicide Severity Rating Scale, vital signs, electrocardiograms, laboratory samples, and growth (height and weight) assessments.

RESULTS

Significantly more patients discontinued because of adverse events during duloxetine (8.2%) treatment than during placebo (3.1%) treatment (p≤0.05). TEAEs in >10% of duloxetine-treated patients were headache and nausea. No completed suicides or deaths occurred. During acute treatment, 6.6% of duloxetine-, 8.0% of fluoxetine-, and 8.2% of placebo-treated patients had worsening suicidal ideation from baseline. Among patients initially randomized to duloxetine or fluoxetine who had suicidal ideation at study baseline, 81% of duloxetine- and 77% of fluoxetine-treated patients had improvements in suicidal ideation at end-point in the 36-week studies. Suicidal behavior occurred in two fluoxetine-treated patients and one placebo-treated patient during acute treatment, and in seven duloxetine-treated patients and one fluoxetine-treated patient during extended treatment. Duloxetine-treated patients had a mean pulse increase of ∼3 beats per minute, and mean blood pressure (both systolic and diastolic) increases of <2.0 mm Hg at week 36. Weight decrease (≥3.5%) during acute treatment occurred with statistically (p≤0.05) greater frequency for both the duloxetine (11.4%) and fluoxetine (11.5%) groups versus the placebo (5.5%) group; however, mean weight increase occurred for both duloxetine and fluoxetine groups during extended treatment.

CONCLUSION

Results from this pooled analysis of two studies were consistent with the known safety and tolerability profile of duloxetine. Clinical Trial Registry Numbers: NCT00849901 and NCT00849693.

Comparative safety and tolerability of duloxetine vs. pregabalin vs. duloxetine plus gabapentin in patients with diabetic peripheral neuropathic pain

OBJECTIVE

The safety and tolerability of three treatments for diabetic peripheral neuropathic pain (DPNP) were compared.

METHODS

A 12-week, randomized, open-label study confirming the non-inferiority of duloxetine (N = 138) vs. pregabalin (N = 134) and the combination of duloxetine plus gabapentin (N = 135) as the primary outcome was previously published. Patients had an inadequate pain response to a stable dose of gabapentin (≥ 900 mg/day) for ≥ 5 weeks prior to study enrolment. Data from that study were assessed in this current analysis for a detailed report of safety and tolerability.

RESULTS

Completion rates did not differ significantly between the groups. Discontinuation because of adverse events was significantly greater in the duloxetine (19.6%) vs. pregabalin group (10.4%; p = 0.04); no differences emerged between the duloxetine vs. duloxetine plus gabapentin (13.3%) groups (p = 0.19) or pregabalin vs. duloxetine plus gabapentin groups (p = 0.57). Adverse event rates varied: nausea, insomnia, hyperhidrosis and decreased appetite were reported significantly more often in patients treated with duloxetine vs. patients treated with pregabalin (each p ≤ 0.01); insomnia significantly more in patients treated with duloxetine vs. duloxetine plus gabapentin (p = 0.01); peripheral oedema significantly more in patients treated with pregabalin vs. duloxetine and duloxetine plus gabapentin (p ≤ 0.001 each) and nausea, hyperhidrosis, decreased appetite and vomiting significantly more in patients treated with duloxetine plus gabapentin vs. pregabalin (each p ≤ 0.05). At end-point, weight change differed significantly among treatment groups: patients in the pregabalin group on average gained weight (1.0 ± 0.04 kg); while, patients in the duloxetine and duloxetine plus gabapentin groups on average lost weight (-2.39 ± 0.04 and -1.06 ± 0.04 kg, respectively) (pregabalin vs. duloxetine, p ≤ 0.001; pregabalin vs. duloxetine plus gabapentin, p ≤ 0.001; duloxetine vs. duloxetine plus gabapentin, p = 0.01).

CONCLUSION

Duloxetine, pregabalin and duloxetine plus gabapentin were generally safe and tolerable for the treatment of DPNP.

Safety, tolerability, and clinical effect of low-dose buprenorphine for treatment-resistant depression in midlife and older adults

OBJECTIVE

To describe the clinical effect and safety of low-dose buprenorphine, a κ-opioid receptor antagonist, for treatment-resistant depression (TRD) in midlife and older adults.

METHOD

In an 8-week open-label study, buprenorphine was prescribed for 15 adults aged 50 years or older with TRD, diagnosed with the Structured Clinical Interview for DSM-IV, between June 2010 and June 2011. The titrated dose of buprenorphine ranged from 0.2-1.6 mg/d. We assessed clinical change in depression, anxiety, sleep, positive and negative affect, and quality of life. The Montgomery-Asberg Depression Rating scale (MADRS) served as the main outcome measure. Tolerability was assessed by documenting side effects and change in vital signs, weight, and cognitive function. Clinical response durability was assessed 8 weeks after discontinuation of buprenorphine.

RESULTS

The mean dose of buprenorphine was 0.4 mg/d (mean maximum dose = 0.7 mg/d). The mean depression score (MADRS) at baseline was 27.0 (SD = 7.3) and at week 8 was 9.5 (SD = 9.5). A sharp decline in depression severity occurred during the first 3 weeks of exposure (mean change = -15.0 [SD = 7.9]). Depression-specific items measuring pessimism and sadness indicated improvement during exposure, supporting a true antidepressant effect. Treatment-emergent side effects (in particular, nausea and constipation) were not sustained, vital signs and weight remained stable, and executive function and learning improved from pretreatment to posttreatment.

CONCLUSION

Low-dose buprenorphine may be a novel-mechanism medication that provides a rapid and sustained improvement for older adults with TRD. Placebo-controlled trials of longer duration are required to assess efficacy, safety, and physiologic and psychological effects of extended exposure to this medication.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT01071538.

Cost effectiveness of duloxetine for osteoarthritis: a Quebec societal perspective

OBJECTIVE

To assess the cost effectiveness of duloxetine compared to other oral postacetaminophen treatments for osteoarthritis (OA) from a Quebec societal perspective.

METHODS

A cost-utility analysis was performed enhancing the Markov model from the 2008 OA guidelines of the National Institute for Health and Clinical Excellence (NICE). The NICE model was extended to include opioid and antidepressant comparators, adding titration, discontinuation, and relevant adverse events (AEs). Comparators included duloxetine, celecoxib, diclofenac, naproxen, hydromorphone, and oxycodone extended release (oxycodone). AEs included gastrointestinal and cardiovascular events associated with nonsteroidal antiinflammatory drugs (NSAIDs), as well as fracture, opioid abuse, and constipation, among others. Costs and incremental cost-effectiveness ratios (ICERs) were estimated in 2011 Canadian dollars. The base case modeled a cohort of 55-year-old patients with OA for a 12-month period of treatment, followed by treatment from a basket of post-discontinuation oral therapies until death. Sensitivity analyses (one-way and probabilistic) were conducted.

RESULTS

Overall, naproxen was the least expensive treatment, whereas oxycodone was the most expensive. Duloxetine accumulated the highest number of quality-adjusted life years (QALYs), with an ICER of $36,291 per QALY versus celecoxib. Duloxetine was dominant over opioids. In subgroup analyses, ICERs for duloxetine versus celecoxib were $15,619 and $20,463 for patients at high risk of NSAID-related AEs and patients ages >65 years, respectively.

CONCLUSION

Duloxetine was cost effective for a cohort of 55-year-old patients with OA, and more so in older patients and those with greater AE risks.

Duloxetine in adults with ADHD: a randomized, placebo-controlled pilot study

OBJECTIVE

To assess the effect of duloxetine on ADHD in adults.

METHOD

In a 6-week double-blind trial, 30 adults with ADHD received placebo or duloxetine 60 mg daily. The Conners' Adult ADHD Rating Scale (CAARS) and the Clinical Global Impression Scales (CGI) were used to assess symptom severity and clinical improvement. The Hamilton Anxiety Rating Scale (HARS) and the Hamilton Depression Rating Scale (HDRS) were used to measure the effect on anxiety and depressive symptoms.

RESULTS

The Duloxetine group showed lower score on CGI-Severity at Week 6 (3.00 vs. 4.07 for placebo, p < .001), greater improvement on CGI-Improvement (2.89 vs. 4.00 at Week 6, p < .001), and greater decreases on five of eight subscales of the CAARS. There was no treatment group effect on HDRS or HARS scores.

CONCLUSION

Duloxetine may be a therapeutic option for adults with ADHD, but further studies are required to replicate these findings in larger samples.

Acute and long-term treatment of late-life major depressive disorder: duloxetine versus placebo

OBJECTIVE

To compare the efficacy of duloxetine with placebo on depression in elderly patients with major depressive disorder.

DESIGN

Multicenter, 24-week (12-week short-term and 12-week continuation), randomized, placebo-controlled, double-blind trial.

SETTING

United States, France, Mexico, Puerto Rico.

PARTICIPANTS

Age 65 years or more with major depressive disorder diagnosis (one or more previous episode); Mini-Mental State Examination score ≥20; Montgomery-Asberg Depression Rating Scale total score ≥20.

INTERVENTION

Duloxetine 60 or 120 mg/day or placebo; placebo rescue possible.

MEASUREMENTS

Primary-Maier subscale of the 17-item Hamilton Depression Rating Scale (HAMD-17) at week 12. Secondary-Geriatric Depression Scale, HAMD-17 total score, cognitive measures, Brief Pain Inventory (BPI), Numeric Rating Scales (NRS) for pain, Clinical Global Impression-Severity scale, Patient Global Impression of Improvement in acute phase and acute plus continuation phase of treatment.

RESULTS

Compared with placebo, duloxetine did not show significantly greater improvement from baseline on Maier subscale at 12 weeks, but did show significantly greater improvement at weeks 4, 8, 16, and 20. Similar patterns for Geriatric Depression Scale and Clinical Global Impression-Severity scale emerged, with significance also seen at week 24. There was a significant treatment effect for all BPI items and 4 of 6 NRS pain measures in the acute phase, most BPI items and half of the NRS measures in the continuation phase. More duloxetine-treated patients completed the study (63% versus 55%). A significantly higher percentage of duloxetine-treated patients versus placebo discontinued due to adverse event (15.3% versus 5.8%).

CONCLUSIONS

Although the antidepressant efficacy of duloxetine was not confirmed by the primary outcome, several secondary measures at multiple time points suggested efficacy. Duloxetine had significant and meaningful beneficial effects on pain.

Clinical experience with duloxetine in the management of chronic musculoskeletal pain. A focus on osteoarthritis of the knee

Duloxetine is a serotonin and norepinephrine reuptake inhibitor (SNRI) with central nervous system activity. Its analgesic efficacy in central pain is putatively related to its influence on descending inhibitory pain pathways. The analgesic efficacy of duloxetine has been demonstrated in four distinct chronic pain conditions. These include neuropathic pain associated with diabetic peripheral neuropathy, fibromyalgia, chronic low back pain, and osteoarthritis knee pain (OAKP). The purpose of this review is to examine the clinical efficacy and safety of duloxetine in the management of chronic OAKP. Three separate randomized, double-blind placebo-controlled trials have demonstrated that (1) a clinically meaningful decrease in pain severity occurs at about 4 weeks relative to placebo, (2) patients receiving duloxetine report better improvements in physical functioning relative to placebo, (3) duloxetine is safe and effective when used adjunctively with nonsteroidal anti-inflammatory drugs, and (4) that there are no new safety signals beyond what has been observed in other indications.

Real-world treatment patterns and opioid use in chronic low back pain patients initiating duloxetine versus standard of care

To describe the use of pain medications in patients with chronic low back pain (CLBP) after initiating duloxetine or standard of care (SOC [muscle relaxants, gabapentin, pregabalin, venlafaxine, and tricyclic antidepressants]) for pain management, pharmacy and medical claims from Surveillance Data, Inc (SDI) Health were analyzed. Adult patients with CLBP who initiated duloxetine or SOC between November 2010 and April 2011 were identified. Treatment initiation was defined as no pill coverage for duloxetine or SOC in the previous 90 days. Included patients had no opioid use in the 90 days before initiation. Propensity score matching was used to select patients with similar baseline demographic and clinical characteristics for duloxetine and SOC cohorts. Compliance with index medication was assessed via medication possession ratio (MPR) and proportion of days covered (PDC) for 6 months after initiation. The proportion of patients receiving opioids and days on opioids after index date were assessed, and regression models were estimated to compare opioid use between cohorts. A total of 766 patients initiated duloxetine and 6,206 patients initiated SOC. After matching, 743 patients were selected for the duloxetine (mean age 57 years; female 74%) and SOC (mean age 57 years; female 75%) cohorts, respectively. Of the duloxetine cohort, 92% started on or below recommended daily dose (≤60 mg). The duloxetine cohort had significantly higher MPR (0.78 versus [vs] 0.60) and PDC (0.50 vs 0.31), were less likely to use opioids (45% vs 61%), and had fewer days on opioids (median 0 vs 7 days) than the SOC cohort (all P < 0.001). After adjusting for demographic and clinical characteristics, the duloxetine cohort initiated opioids later than the SOC cohort (hazard ratio 0.77, 95% confidence interval 0.66–0.89). CLBP patients initiating duloxetine had better compliance with initiated medication and were less likely to use opioids than those initiating SOC.

The risk of bleeding with duloxetine treatment in patients who use nonsteroidal anti-inflammatory drugs (NSAIDs): analysis of placebo-controlled trials and post-marketing adverse event reports

Purpose

To assess the safety of duloxetine with regards to bleeding-related events in patients who concomitantly did, versus did not, use nonsteroidal anti-inflammatory drugs (NSAIDs), including aspirin.

Methods

Safety data from all placebo-controlled trials of duloxetine conducted between December 1993 and December 2010, and post-marketing reports from duloxetine-treated patients in the US Food and Drug Administration Adverse Event Reporting System (FAERS), were searched for bleeding-related treatment-emergent adverse events (TEAEs). The percentage of patients with bleeding-related TEAEs was summarized and compared between treatment groups in all the placebo-controlled studies. Differences between NSAID user and non-user subgroups from clinical trial data were analyzed by a logistic regression model that included therapy, NSAID use, and therapy-by-NSAID subgroup interaction. In addition, to determine if higher duloxetine doses are associated with an increased incidence of bleeding-related TEAEs, and whether the use of concomitant NSAIDs might influence the dose effect if one exists, placebo-controlled clinical trials with duloxetine fixed doses of 60 mg, 120 mg, and placebo were analyzed. Also, the incidence of bleeding-related TEAEs reported for duloxetine alone was compared with the incidence in patients treated with duloxetine and concomitant NSAIDs. Finally, the number of bleeding-related cases reported for duloxetine in the FAERS database was compared with the numbers reported for all other drugs.

Results

Across duloxetine clinical trials, there was a significantly greater incidence of bleeding-related TEAEs in duloxetine- versus placebo-treated patients overall and also in those patients who did not take concomitant NSAIDS, but no significant difference was seen among those patients who did take concomitant NSAIDS. There was no significant difference in the incidence of bleeding-related TEAEs in the subset of patients treated with duloxetine 120 mg once daily versus those treated with 60 mg once daily regardless of concomitant NSAID use. The combination of duloxetine and NSAIDs was associated with a statistically significantly higher incidence of bleeding-related TEAEs compared with duloxetine alone. A similarly higher incidence of bleeding-related TEAEs was seen in patients treated with placebo and concomitant NSAIDs compared with placebo alone. Bleeding-related TEAEs reported in the FAERS database were disproportionally more frequent for duloxetine taken with NSAIDs compared with the full FAERS background, but there was no difference in the reporting of bleeding-related TEAEs when the cases reported for duloxetine taken with NSAIDs were compared against the cases reported for NSAIDs alone.

Conclusion

Concomitant use of NSAIDs was associated with a higher incidence of bleeding-related TEAEs in clinical trials regardless of whether patients were taking duloxetine or placebo; bleeding-related TEAEs did not appear to increase along with duloxetine dose regardless of NSAID use. In spontaneously reported post-marketing data, the combination of duloxetine and NSAID use was not associated with an increased reporting of bleeding-related events when compared to NSAID use alone.

Cost-utility analysis of duloxetine in osteoarthritis: a US private payer perspective

BACKGROUND

Duloxetine has recently been approved in the USA for chronic musculoskeletal pain, including osteoarthritis and chronic low back pain. The cost effectiveness of duloxetine in osteoarthritis has not previously been assessed. Duloxetine is targeted as post first-line (after acetaminophen) treatment of moderate to severe pain.

OBJECTIVE

The objective of this study was to estimate the cost effectiveness of duloxetine in the treatment of osteoarthritis from a US private payer perspective compared with other post first-line oral treatments, including nonsteroidal anti-inflammatory drugs (NSAIDs), and both strong and weak opioids.

METHODS

A cost-utility analysis was performed using a discrete-state, time-dependent semi-Markov model based on the National Institute for Health and Clinical Excellence (NICE) model documented in its 2008 osteoarthritis guidelines. The model was extended for opioids by adding titration, discontinuation and additional adverse events (AEs). A life-long time horizon was adopted to capture the full consequences of NSAID-induced AEs. Fourteen health states comprised the structure of the model: treatment without persistent AE, six during-AE states, six post-AE states and death. Treatment-specific utilities were calculated using the transfer-to-utility method and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) total scores from a meta-analysis of osteoarthritis clinical trials of 12 weeks and longer. Costs for 2011 were estimated using Red Book, The Agency for Healthcare Research and Quality's Healthcare Cost and Utilization Project database, the literature and, sparingly, expert opinion. One-way and probabilistic sensitivity analyses were undertaken, as well as subgroup analyses of patients over 65 years old and a population at greater risk of NSAID-related AEs.

RESULTS

In the base case the model estimated naproxen to be the lowest total-cost treatment, tapentadol the highest cost, and duloxetine the most effective after considering AEs. Duloxetine accumulated 0.027 discounted quality-adjusted life-years (QALYs) more than naproxen and 0.013 more than oxycodone. Celecoxib was dominated by naproxen, tramadol was subject to extended dominance, and strong opioids were dominated by duloxetine. The model estimated an incremental cost-effectiveness ratio (ICER) of US$47,678 per QALY for duloxetine versus naproxen. One-way sensitivity analysis identified the probabilities of NSAID-related cardiovascular AEs as the inputs to which the ICER was most sensitive when duloxetine was compared with an NSAID. When compared with a strong opioid, duloxetine dominated the opioid under nearly all sensitivity analysis scenarios. When compared with tramadol, the ICER was most sensitive to the costs of duloxetine and tramadol. In subgroup analysis, the cost per QALY for duloxetine versus naproxen fell to US$24,125 for patients over 65 years and to US$18,472 for a population at high risk of cardiovascular and gastrointestinal AEs.

CONCLUSION

The model estimated that duloxetine was potentially cost effective in the base-case population and more cost effective for subgroups over 65 years or at high risk of NSAID-related AEs. In sensitivity analysis, duloxetine dominated all strong opioids in nearly all scenarios.

Cost-effectiveness of duloxetine in chronic low back pain: a Quebec societal perspective

STUDY DESIGN

Cost-effectiveness model from a Quebec societal perspective using meta-analyses of clinical trials.

OBJECTIVE

To evaluate the cost-effectiveness of duloxetine in chronic low back pain (CLBP) compared with other post-first-line oral medications.

SUMMARY OF BACKGROUND DATA

Duloxetine has recently received a CLBP indication in Canada. The cost-effectiveness of duloxetine and other oral medications has not previously been evaluated for CLBP.

METHODS

A Markov model was created on the basis of the economic model documented in the 2008 osteoarthritis clinical guidelines of the National Institute for Health and Clinical Excellence. Treatment-specific utilities were estimated via a meta-analysis of CLBP clinical trials and a transfer-to-utility regression estimated from duloxetine CLBP trial data. Adverse event rates of comparator treatments were taken from the National Institute for Health and Clinical Excellence model or estimated by a meta-analysis of clinical trials in osteoarthritis using a maximum-likelihood simulation technique. Costs were developed primarily from Quebec and Ontario public sources as well as the published literature and expert opinion. The 6 comparators were celecoxib, naproxen, amitriptyline, pregabalin, hydromorphone, and oxycodone. Subgroup analyses and 1-way and probabilistic sensitivity analyses were performed.

RESULTS

In the base case, naproxen, celecoxib, and duloxetine were on the cost-effectiveness frontier, with naproxen the least expensive medication, celecoxib with an incremental cost-effectiveness ratio of $19,881, and duloxetine with an incremental cost-effectiveness ratio of $43,437. Other comparators were dominated. Key drivers included the rates of cardiovascular and gastrointestinal adverse events and proton pump inhibitor usage. In subgroup analysis, the incremental cost-effectiveness ratio for duloxetine fell to $21,567 for a population 65 years or older and to $18,726 for a population at higher risk of cardiovascular and gastrointestinal adverse events.

CONCLUSION

The model estimates that duloxetine is a moderately cost-effective treatment for CLBP, becoming more cost-effective for populations older than 65 years or at greater risk of cardiovascular and gastrointestinal events.

LEVEL OF EVIDENCE

1.

Observational study on safety and tolerability of duloxetine in the treatment of female stress urinary incontinence in German routine practice

AIMS

To evaluate the safety and tolerability of duloxetine during routine clinical care in women with stress urinary incontinence (SUI) in Germany, and in particular, to identify previously unrecognized safety issues as uncommon adverse reactions, and the influence of confounding factors present in clinical practice on the safety profile of duloxetine.

METHODS

Office-based urologists, gynaecologists and primary care physicians were asked to document women newly started on treatment for moderate to severe symptoms of SUI. Six thousand eight hundred and fifty-four patients from urologist/gynaecologist practices and 5879 primary care patients were assessed. In a two-armed, observational study with parallel 12 week (urologists and gynaecologists) or 24 week (primary care physicians) design, patients were treated with duloxetine or other conservative treatment. The main outcome measure was the occurrence of adverse events (AEs).

RESULTS

Baseline characteristics differed slightly between patient groups and studies. Duloxetine doses in most patients were lower than recommended. Overall, AE frequency with duloxetine was lower than in controlled studies (15.9% (95% CI 14.9, 16.9) and 9.1% (95% CI 8.2, 10.0) in the 12 and 24 week treatment groups, respectively), but exhibited a similar qualitative spectrum. In the logistic regression models, the following factors were associated with greater AE risk: investigator specialization (gynaecologist vs. urologist and primary care physician), initial duloxetine dose (80 vs. 20 mg day(-1) ) and use of any concomitant medication. Within the 24 week study, a positive screen for depressive disorder was surprisingly common, but no case of attempted suicide was reported in either study.

CONCLUSIONS

Our results from German clinical practice show that women with SUI were often treated with duloxetine doses lower than recommended. This was associated with a low incidence of AEs. Suicide attempts were not reported.

The cost-effectiveness of duloxetine in chronic low back pain: a US private payer perspective

OBJECTIVE

To assess the cost-effectiveness of duloxetine in the treatment of chronic low back pain (CLBP) from a US private payer perspective.

METHODS

A cost-utility analysis was undertaken for duloxetine and seven oral post-first-line comparators, including nonsteroidal anti-inflammatory drugs (NSAIDs), weak and strong opioids, and an anticonvulsant. We created a Markov model on the basis of the National Institute for Health and Clinical Excellence model documented in its 2008 osteoarthritis clinical guidelines. Health states included treatment, death, and 12 states associated with serious adverse events (AEs). We estimated treatment-specific utilities by carrying out a meta-analysis of pain scores from CLBP clinical trials and developing a transfer-to-utility equation using duloxetine CLBP patient-level data. Probabilities of AEs were taken from the National Institute for Health and Clinical Excellence model or estimated from osteoarthritis clinical trials by using a novel maximum-likelihood simulation technique. Costs were gathered from Red Book, Agency for Healthcare Research and Quality's Healthcare Cost and Utilization Project database, the literature, and, for a limited number of inputs, expert opinion. The model performed one-way and probabilistic sensitivity analyses and generated incremental cost-effectiveness ratios (ICERs) and cost acceptability curves.

RESULTS

The model estimated an ICER of $59,473 for duloxetine over naproxen. ICERs under $30,000 were estimated for duloxetine over non-NSAIDs, with duloxetine dominating all strong opioids. In subpopulations at a higher risk of NSAID-related AEs, the ICER over naproxen was $33,105 or lower.

CONCLUSIONS

Duloxetine appears to be a cost-effective post-first-line treatment for CLBP compared with all but generic NSAIDs. In subpopulations at risk of NSAID-related AEs, it is particularly cost-effective.

The effect of initial duloxetine dosing strategy on nausea in korean patients with major depressive disorder

OBJECTIVE

To assess the relative severity of nausea in patients from Korea with major depressive disorder (MDD) who were treated with duloxetine at low (30 mg) or high (60 mg) doses, with or without food, for the first week of an 8 week treatment.

METHODS

Adult patients (n=249), with MDD and a 17-item Hamilton Rating Scale for Depression (HAMD(17)) score of ≥15, received open-label once daily duloxetine. At Week 0, patients were randomized to 4 groups: 30 mg with food (n=63), 60 mg with food (n=59), 30 mg without food (n=64), and 60 mg without food (n=63). At Week 1, all patients switched to duloxetine 60 mg for 7 weeks. The primary outcome measure was item 112 (nausea) of the Association for Methodology and Documentation in Psychiatry adverse event scale. Effectiveness was assessed by change in HAMD(17) total score.

RESULTS

Overall, 94.4% (235/249) of patients completed Week 1 and 55.0% (137/249) of patients completed the study. For Week 1, nausea was significantly less severe for patients who received 30 mg compared with 60 mg duloxetine (p=0.003), regardless of food intake. In all groups, nausea severity was highest at Week 1 and declined throughout the study. HAMD(17) score was reduced in all groups and the most common adverse event reported was nausea (145/249; 58.2%).

CONCLUSION

To minimize nausea, Korean patients with MDD who require duloxetine treatment could be given 30 mg once daily, regardless of food, for the first week followed by 60 mg once daily for the course of therapy.

[Undesired side effects of tapentadol in comparison to oxycodone. A meta-analysis of randomized controlled comparative studies]

OBJECTIVE

Tapentadol is a new centrally acting analgesic with a dual mode of action as an agonist of the µ-opioid receptor and as a norepinephrine reuptake inhibitor. The aim of the present study was to evaluate the results from randomized controlled trials investigating the relative amount of adverse effects using tapentadol or oxycodone for the treatment of pain.

METHODS

A quantitative systematic review was carried out according to the PRISMA recommendations on randomized controlled trials comparing tapentadol and oxycodone in pain treatment. The incidences of typical adverse side effects of opioid-based analgesic therapy (e.g. nausea, vomiting, obstipation or pruritus) were extracted and the pooled relative risks (RR) with corresponding 95% confidence intervals (CI) were calculated.

RESULTS

A total of 9 trials involving 7,948 patients were included and of these 2,810 patients were treated with oxycodone and 5,138 were treated with tapentadol in equivalent analgesic dosages as documented by an equivalent analgesic effect. The risk of typical opioid-based adverse effects, such as nausea (RR 0.61; 95% CI 0.57-0.66), vomiting (RR 0.50, 95% CI: 0.41-0.60), obstipation (RR 0.47, 95%-CI 0.40-0.56), dizziness (RR 0.86, 95% CI 0.78-0.95), somnolence (RR 0.76, 95% CI 0.67-0.86) and pruritus (RR 0.46, 95% CI 0.37-0.58) was reduced when tapentadol was used for analgesic treatment. These adverse effects were investigated in all nine trials. The risk for dryness of the mouth (6 trials, 6,218 patients, RR 1.79, 95% CI 1.40-2.29) and dyspepsia (1 trial, 646 patients, RR 2.75, 95% CI 1.09-6.94) was increased when tapentadol was used instead of oxycodone. There were no significant differences in the relative risk for any other investigated adverse effect such as dysentery, headache or fatigue.

CONCLUSION

The results show that using tapentadol significantly reduces the risk of the typical opioid-based adverse effects compared with oxycodone while providing equivalent analgesic treatment.

Single-agent duloxetine ingestions

Duloxetine is a serotonin and norepinephrine reuptake inhibitor, which is mainly used to treat depression. This retrospective study describes the demographic and clinical effects of duloxetine ingestions reported to the National Poison Data System (NPDS). NPDS data were searched for duloxetine exposures between 2004 and 2010. A total of 11,373 patients were included and exposures were divided into three groups of ages ≤6 years old, 7–12 years and >12 years. Neurological clinical effects occurred in 6.1% of the patients aged ≤6 years, 13.0% of the patients aged 7–12 years and 24.6% of the patients aged >12 years. Cardiovascular effects occurred in 1.4% of the patients aged ≤6 years old, 2.5% of the patients aged 7–12 years and 11.6% of the patients aged >12 years. Gastrointestinal effects occurred in 4.1% of the patients aged ≤6 years old, 16.6% of the patients aged 7–12 years and 13.8% of the patients aged >12 years. Tachycardia, nausea, vomiting, agitation/irritability, dizziness/vertigo and drowsiness were among the most common clinical effects in all three groups. Overall, 61.4% of the patients aged ≤6 years and 77.5% of the patients aged 7–12 years were managed in a non–health care facility, while 55.8% of the patients aged >12 years were referred to or already in a health care facility. We conclude that the majority of ingestions are benign in both pediatrics and adults. Most symptomatic patients have neurologic, gastrointestinal and cardiovascular effects. Most pediatric patients will be able to be managed in a non–health care facility.

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.

Tolerability aspects in duloxetine-treated patients with depression: Should one use a lower starting dose in clinical practice?

OBJECTIVE

This study questions whether a lower starting dose of duloxetine (DLX) could be beneficial for patients with depression, in terms of tolerability and safety in routine clinical care.

RESEARCH DESIGN AND METHODS

Post-hoc analyses of a multicenter, prospective, non-interventional, 6-month study in adult outpatients with a depressive episode was undertaken.

MAIN OUTCOME MEASURES

Treatment-emergent adverse events (TEAEs), serious adverse events (SAEs), discontinuations due to TEAEs and hospitalizations due to depression, were all documented at 2 weeks, 4 weeks, 3 months and 6 months after treatment initiation/switch to DLX.

RESULTS

Of 4517 patients enrolled, 4313 were included for TEAE evaluation. TEAEs occurred in 17.2% of patients, and SAEs occurred in 0.79% of patients, including one case of suicidal ideation. 1404 patients discontinued within 6 months (TEAEs: n = 119). Starting treatment with 30 mg/day DLX (72.7%) was favored in females, or after inadequate efficacy of previous antidepressant treatment; 60 mg/day DLX was favored in more severe depression and patients receiving concomitant pain medication.

CONCLUSION

Initiating treatment with 60 mg/day DLX was not associated with poorer tolerability in this study. Physicians may be guided by their clinical experience to carefully consider the individual benefit/risk ratio and TEAE susceptibility when deciding to start treatment with a higher or a lower dose of DLX.

A review of duloxetine 60 mg once-daily dosing for the management of diabetic peripheral neuropathic pain, fibromyalgia, and chronic musculoskeletal pain due to chronic osteoarthritis pain and low back pain

BACKGROUND

Duloxetine is a selective dual neuronal serotonin (5-Hydroxytryptamine, 5-HT) and norepinephrine reuptake inhibitor (SSNRI). It is indicated in the United States for treatment of major depressive disorder (MDD), generalized anxiety disorder (GAD), and several chronic pain conditions, including management of diabetic peripheral neuropathic pain, fibromyalgia, and chronic musculoskeletal pain due to chronic osteoarthritis (OA) pain and chronic low back pain (LBP). Its use for antidepressant and anxiolytic actions has been extensively reviewed previously. We here review the evidence for the efficacy of 60 mg once-daily dosing of duloxetine for chronic pain conditions.

METHOD

The literature was searched for clinical trials in humans conducted in the past 10 years involving duloxetine.

RESULTS

There were 199 results in the initial search. Studies not in the English language were excluded. We then included only studies of diabetic peripheral neuropathic pain, fibromyalgia, and chronic musculoskeletal pain (OA and LBP). Studies of painful symptoms reported in mental health studies were excluded. This resulted in 32 studies. Articles that did not include a 60 mg/day daily dose as a study arm were excluded. This resulted in 30 studies, broken down as follows: 12 for diabetic peripheral neuropathy, 9 for fibromyalgia, 6 for LBP, and 3 for OA pain.

CONCLUSIONS

The studies reviewed report that duloxetine 60 mg once-daily dosing is an effective option for the management of diabetic peripheral neuropathic pain, fibromyalgia, and chronic musculoskeletal pain due to chronic OA pain and chronic LBP. As these pains are often comorbid with MDD or GAD, duloxetine might possess the pharmacologic properties to be a versatile agent able to address several symptoms in these patients. With adequate attention to FDA prescribing guidance regarding safety and drug-drug interactions, duloxetine 60 mg once-daily dosing appears to be an effective option in the appropriate pain patient population.

Duloxetine in the management of chronic musculoskeletal pain

Chronic musculoskeletal pain is among the most frequent painful complaints that healthcare providers address. The bulk of these complaints are chronic low back pain and chronic osteoarthritis. Osteoarthritis is the most common form of arthritis in the United States. It is a chronic degenerative disorder characterized by a loss of cartilage, and occurs most often in older persons. The management of osteoarthritis and chronic low back pain may involve both nonpharmacologic (eg, weight loss, resistive and aerobic exercise, patient education, cognitive behavioral therapy) and pharmacologic approaches. Older adults with severe osteoarthritis pain are more likely to take analgesics than those with less severe pain. The pharmacologic approaches to painful osteoarthritis remain controversial, but may include topical as well as oral nonsteroidal antiinflammatory drugs, acetaminophen, duloxetine, and opioids. The role of duloxetine for musculoskeletal conditions is still evolving.

Non-surgical treatment of osteoarthritis-related pain in the elderly

Osteoarthritis (OA), the third most common diagnosis in the elderly [1], causes significant pain leading to disability and decreased quality of life in subjects 65 years and older [2]. Traditionally, clinicians have relied heavily on the use of non-steroidal anti-inflammatory drugs (NSAIDs) to treat the pain of OA, as numerous studies have proven these agents to be effective. The cardiovascular, gastrointestinal, renal and hepatic toxicities of NSAIDs have limited their use, particularly in the elderly. Acetaminophen has been recommended as initial therapy due to relative safety. Several other topical, oral and intra-articular agents are available today, with use limited by efficacy and side effect profiles. Many non-pharmacologic approaches are available but underused, and may be attractive choices to avoid poly-pharmacy in older patients. We will attempt to highlight the evidence behind available non-surgical therapies for OA while paying specific attention to issues in geriatric 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.

Evaluation of duloxetine for chronic pain conditions

Summary Duloxetine hydrochloride (duloxetine) is used as a nonopioid analgesic for the treatment of certain chronic pain conditions. It is a serotonin and norepinephrine reuptake inhibitor and has been approved in the USA for the management of both diabetic peripheral neuropathic pain and fibromyalgia. In addition, based on several studies demonstrating that duloxetine was efficacious in the management of chronic low back pain and chronic pain caused by osteoarthritis, duloxetine was approved for the management of chronic musculoskeletal pain. Effect sizes in studies of each of the aforementioned chronic pain conditions are comparable with other commonly used pain medications. Treatment-emergent adverse events are generally mild to moderate in severity, and tend to occur early and transiently.