The Local and Systemic Actions of Duloxetine in Allodynia and Hyperalgesia Using a Rat Skin Incision Pain Model

Effect of duloxetine on pain and opioid consumption after total knee and hip arthroplasty: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Although duloxetine has shown a positive effect on pain relief with hip and knee osteoarthritis, there is no pooled analysis of duloxetine for pain relief and opioid consumption in patients after total hip or knee arthroplasty.

AIM

This systematic review and meta-analysis aimed to analyze pain control, opioid consumption, and associated adverse events of perioperative administration of duloxetine after total hip or knee arthroplasty.

METHOD

After being registered with PROSPERO (CRD42022323202), the databases of MEDLINE, PubMed, Embase, Web of Science, Cochrane Library, and ClinicalTrials.gov were searched from inception until March 20, 2023, for randomized controlled trials (RCTs). Primary outcomes were the visual Analog Scale (VAS) pain scores at rest (rVAS) and upon ambulation (aVAS). Secondary outcomes were postoperative opioid consumption quantified as oral morphine milligram equivalents (MMEs) and adverse effects of duloxetine.

RESULTS

Nine RCTs with 806 cases were included. Duloxetine was associated with lower VAS scores at different times after surgery (24 h, two weeks, and ≥ 3 months). Compared to placebo, perioperative daily duloxetine use significantly reduced daily opioid MMEs at 24 h (standard mean deviation [SMD] -0.71, 95% confidence interval [95% CI] -1.19 to -0.24, P = 0.003), three days (SMD -1.10, 95% CI -1.70 to -0.50, P = 0.0003), and one week (SMD -1.18, 95% CI -1.99 to -0.38, P = 0.004) after surgery. The duloxetine group had a significantly lower rate of nausea (odds ratio 0.62, 95% CI [0.41 to 0.94], P = 0.02) and a higher rate of drowsiness and somnolence (odds ratio 1.87, 95% CI [1.13 to 3.07], P = 0.01) compared to the placebo group. No significant differences were observed in the rates of other adverse events.

CONCLUSION

 Perioperative duloxetine significantly decreased postoperative pain and opioid consumption with good safety profiles. Further high quality designed and well-controlled randomized trials are warranted.

Postoperative acute pain management with duloxetine as compared to placebo: A systematic review with meta-analysis of randomized clinical trials

BACKGROUND

Duloxetine has been used as an adjunct in multimodal analgesia for acute postoperative pain in clinical studies. This meta-analysis aims to conclude whether oral duloxetine, when given perioperatively, is any better than a placebo in managing postoperative pain. Effects of duloxetine on postoperative pain scores, time to first rescue analgesia, postoperative rescue analgesia consumption, side effects attributable to duloxetine, and patient satisfaction profile were assessed.

METHOD

MEDLINE, Web of Science, EMBASE, Scholar Google, and the Cochrane Central Register of Controlled Trials (CENTRAL) were searched with keywords including "Duloxetine" AND "postoperative pain", "Duloxetine" AND "acute pain" and with "Duloxetine" till October 2022. This meta-analysis included randomized clinical trials in which perioperative duloxetine 60 mg per oral was administered not more than 7 days before surgery and for at least 24 after surgery but not more than 14 days after surgery. All RCTs in which the comparator is placebo and outcomes related to analgesic efficacy like pain scores, opioid consumption, and side effects of duloxetine until 48 h postoperatively were included. Data were extracted from the studies and a risk of bias summary was formed using the Cochrane Collaboration tool. Effect sizes were given as standardized mean differences for continuous outcomes and risk ratios (RR) by the Mantel-Haenszel test for the categorical outcome. Confirmation of publication bias was done by Egger's regression test (p < 0.05). If publication bias or heterogeneity was detected, the trim-and-fill method was used to calculate the adjusted effect size. Sensitivity analysis was done by leaving one out method after excluding the study with a high risk of bias. Subgroup analysis was done based on the type of surgery and gender. The study was prospectively registered in the PROSPERO under the registration number CRD42019139559.

FINDINGS

29 studies with 2043 patients met the inclusion criteria and were reviewed for this meta-analysis. Postoperative pain scores at 24 h [Std. Mean Difference (95% CI); -0.69 (-1.07, -0.32)] and at 48 h [-1.13 (-1.68, -0.58)] are significantly less with duloxetine (p-value < 0.05). Time to first rescue analgesia was significantly more in patients where duloxetine was administered [1.27 (1.10, 1.45); p-value > 0.05]. Opioid consumption up to 24 h [-1.82 (-2.46, -1.18)] and 48 h [-2.48 (-3.46, -1.50)] was significantly less (p-value < 0.05) in patients who received duloxetine. Complications and recovery profiles were similar in patients receiving either duloxetine or a placebo.

INTERPRETATION

Based on GRADE findings, we conclude that there is low to moderate evidence to advocate the use of duloxetine for managing postoperative pain. Further trials are needed to replicate or refute these results based on robust methodology.

Intensity-adjustable pain management with prolonged duration based on phase-transitional nanoparticles-assisted ultrasound imaging-guided nerve blockade

Background

The lack of a satisfactory strategy for postoperative pain management significantly impairs the quality of life for many patients. However, existing nanoplatforms cannot provide a longer duration of nerve blockage with intensity-adjustable characteristics under imaging guidance for clinical applications.

Results

To overcome this challenge, we proposed a biocompatible nanoplatform that enables high-definition ultrasound imaging-guided, intensity-adjustable, and long-lasting analgesia in a postoperative pain management model in awake mice. The nanoplatform was constructed by incorporating perfluoropentane and levobupivacaine with red blood cell membranes decorated liposomes. The fabricated nanoplatform can achieve gas-producing and can finely escape from immune surveillance in vivo to maximize the anesthetic effect. The analgesia effect was assessed from both motor reactions and pain-related histological markers. The findings demonstrated that the duration of intensity-adjustable analgesia in our platform is more than 20 times longer than free levobupivacaine injection with pain relief for around 3 days straight. Moreover, the pain relief was strengthened by repeatable ultrasound irradiation to effectively manage postoperative pain in an intensity-adjustable manner. No apparent systemic and local tissue injury was detected under different treatments.

Conclusion

Our results suggest that nanoplatform can provide an effective strategy for ultrasound imaging-guided intensity-adjustable pain management with prolonged analgesia duration and show considerable transformation prospects.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12951-022-01707-z.

The effects of a short-term perioperative duloxetine treatment on post-colectomy pain: A randomized, controlled clinical trial

STUDY OBJECTIVE

To test the hypothesis that duloxetine reduces postoperative morphine consumption and pain intensity in patients undergoing major colonic surgeries.

DESIGN

Single-center, prospective, double-blinded, randomized, controlled trial.

SETTING

Tertiary university hospital, from December 2019 to September 2021.

PATIENTS

Sixty 18-85 years old, ASA I - III patients undergoing elective open major colonic surgeries were randomly allocated into duloxetine (duloxetine) or placebo (placebo) groups (n = 30 per group).

INTERVENTIONS

Duloxetine 60 mg or placebo was administered orally 2 h before and 24 h after surgery.

MEASUREMENTS

PCA morphine consumption, surgical pain at rest, and movement measured on 10-cm visual analog scales (VAS), Ramsay sedation scores, and the incidence of adverse effects potentially associated with duloxetine were assessed at patients' admission to the post-anesthesia care unit (PACU), 6, 24, and 48 h postoperatively (PO).

MAIN RESULTS

After adjusting for age, BMI, ASA physical status, education level, and incision type, no differences were found between groups in PCA morphine consumption 24 PO h (duloxetine = 5.44 ± 2.06 mg; placebo = 10.33 ± 2.06 mg, p = 0.62) or 48 h PO (duloxetine = 9.18 ± 2.06 mg, placebo = 12.93 ± 2.06, p = 1). Pain at rest also did not differ between groups at 24 h PO (duloxetine = 1.76 ± 0.67 cm; placebo = 1 ± 0.67 cm, p = 1) or at 48 h PO (duloxetine = 0.84 ± 0.67 cm; placebo = 0.49 ± 0.67 cm, p = 1). Similarly, groups did not differ regarding pain on movement at 24 h PO (duloxetine = 2.09 ± 0.68 cm; placebo = 1.80 ± 0.68, p = 1) or at 48 h PO (duloxetine = 1.16 ± 0.68 cm; placebo = 0.88 ± 0.68 cm, p = 1). Sedation scores and adverse effects also did not differ between groups.

CONCLUSION

Under this study's conditions, short-term duloxetine did not reduce total opioid consumption or pain intensity during the initial 48 h following major colon surgery.

The Efficacy of Preoperative Duloxetine in Patients Undergoing Major Abdominal Cancer Surgery: A Randomized Controlled Trial

OBJECTIVE

We aimed to evaluate the analgesic efficacy as well as the postoperative quality of recovery of preoperative oral duloxetine a serotonin and norepinephrine reuptake inhibitor for patients undergoing major abdominal cancer surgery.

MATERIALS AND METHODS

Sixty-two patients, undergoing major abdominal cancer surgery were divided into 2 equal groups, received oral duloxetine 60 mg (2 h preoperative) or placebo. Postoperative 48 hours morphine consumption, visual analog scale pain score, and quality of recovery were measured.

RESULTS

The cumulative 48 hours morphine consumption was significantly reduced in the duloxetine group compared with the placebo group (mean±SD) (5.2±3.2 vs. 12.9±3.4 mg), mean difference (95% confidence interval) 7.6 mg (5.9-9.3) P<0.001. The time to first morphine request was delayed significantly in the duloxetine group, median (interquartile range), 25 (19 to 38) versus 8 (4 to 9) hours, P<0.001. The duloxetine group had lower pain scores than the placebo group at 8, 12, 16, and 24 hours postoperatively, however, nonsignificant changes were observed at 0, 2, 4, 36, and 48 hours postoperatively. Participants in the duloxetine group had a better postoperative quality of recovery than the placebo group. The median (interquartile range) of the global quality of recovery-40 scoring system for the duloxetine group was 185 (180 to 191) compared with 170 (163 to 175) in the placebo group (P<0.001).

DISCUSSION

A single preoperative dose of oral duloxetine, 60 mg for patients subjected to major abdominal cancer surgery reduced postoperative pain, decreased opioid consumption, and improved the quality of recovery.

Prevalence and characteristics of cutaneous allodynia in probable migraine

Cutaneous allodynia (CA) is a pain in response to non-nociceptive stimulation and a marker of central sensitisation. Probable migraine (PM) is a migraine subtype that fulfils all but one criterion of migraine. Headache intensity and the disability of individuals with PM are similar or lower than individuals with migraine. This study compared CA prevalence and characteristics of PM and migraine using a nationally representative sample in Korea. The Allodynia Symptom Checklist-12 (ASC-12) was used to assess CA (ASC-12 score ≥ 3). PM and migraine prevalence were 11.6% and 5.0%, respectively. CA prevalence did not significantly differ between PM and migraine (14.5% vs. 16.0%, p = 0.701). Participants with PM with CA reported a higher monthly headache frequency (3.3 ± 4.3 vs. 1.8 ± 3.6, p = 0.044), more severe headache intensity (Visuals Analogue Scale, 6.0 [4.0–7.0] vs. 5.0 [3.0–6.0], p = 0.002), and higher impact of headache (Headache Impact Test-6, 56.3 ± 7.2 vs. 48.3 ± 8.0, p < 0.001) than those without CA. Multiple regression analyses revealed that headache frequency and intensity, anxiety, and depression were significant factors for CA in participants with PM. In conclusion, CA prevalence among participants with PM and migraine were comparable. Anxiety, depression, and headache frequency and intensity were significant factors for CA in participants with PM.

Platinum-induced peripheral neurotoxicity: From pathogenesis to treatment

Platinum-induced peripheral neurotoxicity (PIPN) is a common side effect of platinum-based chemotherapy that may cause dose reduction and discontinuation, with oxaliplatin being more neurotoxic. PIPN includes acute neurotoxicity restricted to oxaliplatin, and chronic non-length-dependent sensory neuronopathy with positive and negative sensory symptoms and neuropathic pain in both upper and lower limbs. Chronic sensory axonal neuropathy manifesting as stocking-and-glove distribution is also frequent. Worsening of neuropathic symptoms after completing the last chemotherapy course may occur. Motor and autonomic involvement is uncommon. Ototoxicity is frequent in children and more commonly to cisplatin. Platinum-based compounds result in more prolonged neuropathic symptoms in comparison to other chemotherapy agents. Patient reported outcomes questionnaires, clinical evaluation and instrumental tools offer complementary information in PIPN. Electrodiagnostic features include diffusely reduced/abolished sensory action potentials, in keeping with a sensory neuronopathy. PIPN is dependent on cumulative dose but there is a large variability in its occurrence. The search for additional risk factors for PIPN has thus far yielded no consistent findings. There are currently no neuroprotective strategies to reduce the risk of PIPN, and symptomatic treatment is limited to duloxetine that was found effective in a single phase III intervention study. This review critically examines the pathogenesis, incidence, risk factors (both clinical and pharmacogenetic), clinical phenotype and management of PIPN.

Relationship Between Pain Alleviation and Disease-specific Health-related Quality of Life Measures in Patients With Chronic Low Back Pain Receiving Duloxetine: Exploratory Post Hoc Analysis of a Japanese Phase 3 Randomized Study

This post hoc analysis of a Japanese phase 3 randomized study (ClinicalTrials.gov identifier: NCT01855919) investigated relationships between pain severity (assessed by the Brief Pain Inventory [BPI]) and disease-specific health-related quality of life (assessed by the 24-item Roland-Morris Disability Questionnaire [RDQ-24]) in duloxetine-treated patients with chronic low back pain (CLBP).

Perioperative duloxetine for acute postoperative analgesia: a meta-analysis of randomized trials

BACKGROUND

Multimodal analgesia is a fundamental part of modern surgery and enhanced recovery pathways. Duloxetine, a serotonin and norepinephrine reuptake inhibitor, has been validated for the treatment of chronic neuropathic pain. The evidence for duloxetine as an adjunct for the treatment of acute postoperative pain remains controversial. We conducted a meta-analysis to determine the efficacy of duloxetine in the acute perioperative setting.

METHODS

A literature search was conducted in the major databases (PubMed, EMBASE and Google Scholar) for randomized controlled trials (RCTs) evaluating duloxetine compared with placebo control for acute postoperative pain. The primary outcome was postoperative pain assessed at 2, 4, 6, 24 and 48 hours time frames. Secondary outcomes included postoperative opioid administration, as well as side effects, such as postoperative nausea/vomiting (PONV), pruritus, dizziness and headache.

RESULTS

574 patients (n=9 RCTs) were included in the analysis, divided between duloxetine (n=285 patients) and placebo (n=289 patients). Duloxetine use was associated with a significant reduction in pain scores as early as 4 (mean difference (MD) -0.9, 95% CI -1.33 to -0.47) and as late as 48 (MD -0.94, 95% CI -1.56 to -0.33) hours postoperatively compared with placebo. In addition, duloxetine was associated with a significant reduction in opioid administration at 24 (standardized MD (SMD) -2.24, 95% CI -4.28 to -0.19) and 48 (SMD -2.21, 95% CI -4.13 to -0.28) hours as well as a significant reduction in PONV (risk ratio 0.69, 95% CI 0.49 to 0.95, p=0.03) compared with placebo. There was no difference between groups in other side effects.

CONCLUSION

Duloxetine, a non-opioid neuromodulator, may provide efficacy for the treatment of acute perioperative pain. Additional prospective studies are required to establish optimal perioperative dosing regimens, role in the setting of a comprehensive multimodal analgesic plan and impact on chronic postsurgical pain.

PROSPERO REGISTRATION NUMBER

CRD42019121416.

Mechanisms, Predictors, and Challenges in Assessing and Managing Painful Chemotherapy-Induced Peripheral Neuropathy

OBJECTIVE

To describe the known predictors and pathophysiological mechanisms of chronic painful chemotherapy-induced peripheral neuropathy (CIPN) in cancer survivors and the challenges in assessing and managing it.

DATA SOURCES

PubMed/Medline, CINAHL, Scopus, and PsycINFO.

CONCLUSION

The research on chronic painful CIPN is limited. Additional research is needed to identify the predictors and pathophysiological mechanisms of chronic painful CIPN to inform the development of assessment tools and management options for this painful and possibly debilitating condition.

IMPLICATIONS FOR NURSING PRACTICE

Recognition of the predictors of chronic painful CIPN and proactive CIPN assessment and palliative management are important steps in reducing its impact on physical function and quality of life.

Duloxetine Improves Spinal Cord Stimulation Outcomes for Chronic Pain

OBJECTIVE

Spinal cord stimulation (SCS) has been shown to be effective in treating chronic pain in patients with varying etiologies. However, the impact of pharmacological treatment on augmenting response to SCS has not been previously studied.

METHODS

We enrolled 108 patients who had undergone SCS surgery and documented their pain preoperatively and at 12 months postoperatively using the Numeric Rating Scale (NRS), McGill Pain Questionnaire (MPQ), Beck Depression Inventory (BDI), Oswestry Disability Index (ODI), Pain Catastrophizing Scale (PCS), and Global Impression of Change (GIC). Pain outcomes were compared between patients receiving SCS alone and in addition to duloxetine.

RESULTS

At 1-year follow-up, patients receiving duloxetine and SCS (n = 41) had better pain relief in the affective component of MPQ (p < 0.05) than those receiving SCS alone (n = 71). Patients on duloxetine with SCS also were significantly more willing to receive SCS again (p < 0.01). This willingness appeared to be duloxetine dose dependent (p < 0.05). Patients receiving pregabalin or gabapentin with SCS did not have significantly more pain relief than patients receiving SCS alone.

CONCLUSION

This study shows the combination therapy to be an effective strategy to provide more holistic pain relief and further improve the quality of life of SCS patients.

Serotonin and Norepinephrine Reuptake Inhibitors

This chapter covers antidepressants that fall into the class of serotonin (5-HT) and norepinephrine (NE) reuptake inhibitors. That is, they bind to the 5-HT and NE transporters with varying levels of potency and binding affinity ratios. Unlike the selective serotonin (5-HT) reuptake inhibitors (SSRIs), most of these antidepressants have an ascending rather than a flat dose-response curve. The chapter provides a brief review of the chemistry, pharmacology, metabolism, safety and adverse effects, clinical use, and therapeutic indications of each antidepressant. Venlafaxine, a phenylethylamine, is a relatively weak 5-HT and weaker NE uptake inhibitor with a 30-fold difference in binding of the two transporters. Therefore, the drug has a clear dose progression, with low doses predominantly binding to the 5-HT transporter and more binding of the NE transporter as the dose ascends. Venlafaxine is metabolized to the active metabolite O-desmethylvenlafaxine (ODV; desvenlafaxine) by CYP2D6, and it therefore is subject to significant inter-individual variation in blood levels and response dependent on variations in CYP2D6 metabolism. The half-life of venlafaxine is short at about 5 h, with the ODV metabolite being 12 h. Both parent compound and metabolite have low protein binding and neither inhibit CYP enzymes. Therefore, both venlafaxine and desvenlafaxine are potential options if drug-drug interactions are a concern, although venlafaxine may be subject to drug-drug interactions with CYP2D6 inhibitors. At low doses, the adverse effect profile is similar to an SSRI with nausea, diarrhea, fatigue or somnolence, and sexual side effects, while venlafaxine at higher doses can produce mild increases in blood pressure, diaphoresis, tachycardia, tremors, and anxiety. A disadvantage of venlafaxine relative to the SSRIs is the potential for dose-dependent blood pressure elevation, most likely due to the NE reuptake inhibition caused by higher doses; however, this adverse effect is infrequently observed at doses below 225 mg per day. Venlafaxine also has a number of potential advantages over the SSRIs, including an ascending dose-antidepressant response curve, with possibly greater overall efficacy at higher doses. Venlafaxine is approved for MDD as well as generalized anxiety disorder, social anxiety disorder, and panic disorder. Desvenlafaxine is the primary metabolite of venlafaxine, and it is also a relatively low-potency 5-HT and NE uptake inhibitor. Like venlafaxine it has a favorable drug-drug interaction profile. It is subject to CYP3A4 metabolism, and it is therefore vulnerable to enzyme inhibition or induction. However, the primary metabolic pathway is direct conjugation. It is approved in the narrow dose range of 50-100 mg per day. Duloxetine is a more potent 5-HT and NE reuptake inhibitor with a more balanced profile of binding at about 10:1 for 5HT and NE transporter binding. It is also a moderate inhibitor of CYP2D6, so that modest dose reductions and careful monitoring will be needed when prescribing duloxetine in combination with drugs that are preferentially metabolized by CYP2D6. The most common side effects identified in clinical trials are nausea, dry mouth, dizziness, constipation, insomnia, asthenia, and hypertension, consistent with its mechanisms of action. Clinical trials to date have demonstrated rates of response and remission in patients with major depression that are comparable to other marketed antidepressants reviewed in this book. In addition to approval for MDD, duloxetine is approved for diabetic peripheral neuropathic pain, fibromyalgia, and musculoskeletal pain. Milnacipran is marketed as an antidepressant in some countries, but not in the USA. It is approved in the USA and some other countries as a treatment for fibromyalgia. It has few pharmacokinetic and pharmacodynamic interactions with other drugs. Milnacipran has a half-life of about 10 h and therefore needs to be administered twice per day. It is metabolized by CYP3A4, but the major pathway for clearance is direct conjugation and renal elimination. As with other drugs in this class, dysuria is a common, troublesome, and dose-dependent adverse effect (occurring in up to 7% of patients). High-dose milnacipran has been reported to cause blood pressure and pulse elevations. Levomilnacipran is the levorotary enantiomer of milnacipran, and it is pharmacologically very similar to the racemic compound, although the side effects may be milder within the approved dosing range. As with other NE uptake inhibitors, it may increase blood pressure and pulse, although it appears to do so less than some other medications. All medications in the class can cause serotonin syndrome when combined with MAOIs.

Effects of subthalamic deep brain stimulation with duloxetine on mechanical and thermal thresholds in 6OHDA lesioned rats

Chronic pain is the most common non-motor symptom of Parkinson's disease (PD) and is often overlooked. Unilateral 6-hydroxydopamine (6-OHDA) medial forebrain bundle lesioned rats used as models for PD exhibit decreased sensory thresholds in the left hindpaw. Subthalamic deep brain stimulation (STN DBS) increases mechanical thresholds and offers improvements with chronic pain in PD patients. However, individual responses to STN high frequency stimulation (HFS) in parkinsonian rats vary with 58% showing over 100% improvement, 25% showing 30-55% improvement, and 17% showing no improvement. Here we augment STN DBS by supplementing with a serotonin-norepinephrine reuptake inhibitor commonly prescribed for pain, duloxetine. Duloxetine was administered intraperitoneally (30mg/kg) in 15 parkinsonian rats unilaterally implanted with STN stimulating electrodes in the lesioned right hemisphere. Sensory thresholds were tested using von Frey, Randall-Selitto and hot-plate tests with or without duloxetine, and stimulation to the STN at HFS (150Hz), low frequency (LFS, 50Hz), or off stimulation. With HFS or LFS alone (left paw; p=0.016; p=0.024, respectively), animals exhibited a higher mechanical thresholds stable in the three days of testing, but not with duloxetine alone (left paw; p=0.183). Interestingly, the combination of duloxetine and HFS produced significantly higher mechanical thresholds than duloxetine alone (left paw, p=0.002), HFS alone (left paw, p=0.028), or baseline levels (left paw; p<0.001). These findings show that duloxetine paired with STN HFS increases mechanical thresholds in 6-OHDA-lesioned animals more than either treatment alone. It is possible that duloxetine augments STN DBS with a central and peripheral additive effect, though a synergistic mechanism has not been excluded.

Differential inhibition of cardiac and neuronal Na(+) channels by the selective serotonin-norepinephrine reuptake inhibitors duloxetine and venlafaxine

Duloxetine and venlafaxine are selective serotonin-norepinephrine-reuptake-inhibitors used as antidepressants and co-analgesics. While venlafaxine rather than duloxetine induce cardiovascular side-effects, neither of the substances are regarded cardiotoxic. Inhibition of cardiac Na(+)-channels can be associated with cardiotoxicity, and duloxetine was demonstrated to block neuronal Na(+)-channels. The aim of this study was to investigate if the non-life threatening cardiotoxicities of duloxetine and venlafaxine correlate with a weak inhibition of cardiac Na(+)-channels. Effects of duloxetine, venlafaxine and amitriptyline were examined on endogenous Na(+)-channels in neuroblastoma ND7/23 cells and on the α-subunits Nav1.5, Nav1.7 and Nav1.8 with whole-cell patch clamp recordings. Tonic block of the cardiac Na(+)-channel Nav1.5 and rat-cardiomyocytes (CM) revealed a higher potency for duloxetine (Nav 1.5 IC50 14±1µM, CM IC50 27±3µM) as compared to venlafaxine (Nav 1.5 IC50 671±26µM, CM IC50 452±34µM). Duloxetine was as potent as the cardiotoxic antidepressant amitriptyline (IC50 13±1µM). While venlafaxine almost failed to induce use-dependent block on Nav1.5 and cardiomyocytes, low concentrations of duloxetine (1, 10µM) induced prominent use-dependent block similar to amitriptyline. Duloxetine, but not venlafaxine stabilized fast and slow inactivation and delayed recovery from inactivation. Duloxetine induced an unselective inhibition of neuronal Na(+)-channels (IC50 ND7/23 23±1µM, Nav1.7 19±2µM, Nav1.8 29±2). Duloxetine, but not venlafaxine inhibits cardiac Na(+)-channels with a potency similar to amitriptyline. These data indicate that an inhibition of Na(+)-channels does not predict a clinically relevant cardiotoxicity.