Safety and tolerability of duloxetine treatment of diabetic peripheral neuropathic pain between patients with and without cardiovascular conditions

Effectiveness of Duloxetine versus Other Therapeutic Modalities in Patients with Diabetic Neuropathic Pain: A Systematic Review and Meta-Analysis

Objectives: Diabetic peripheral neuropathy (DPN) is a chronic complication of diabetes mellitus (DM) with symptoms like intense pain and impaired quality of life. This condition has no treatment; instead, the pain is managed with various antidepressants, including duloxetine. The aim of this study is to analyze the evidence on the efficacy of duloxetine in the management of DPN. Methods: A systematic search in different databases was conducted using the keywords "diabetic neuropathy", "duloxetine therapy", "neuropathic pain", and "Diabetes Mellitus". Finally, eight studies were included in this meta-analysis. Results: All articles comparing duloxetine at different doses vs. a placebo reported significant differences in favor of duloxetine on pain scales like 24 h Average Pain Severity (standardized mean difference [SMD] = -1.06, confidence interval [CI] = -1.09 to -1.03, and p < 0.00001) and BPI Severity (SMD = -0.70, CI = -0.72 to -0.68, and p < 0.00001), among others. A total of 75% of the meta-analyses of studies comparing duloxetine at different doses showed a tendency in favor of the 120 mg/d dose. There were significant differences in favor of duloxetine when compared to routine care on the Euro Quality of Life (SMD = -0.04, CI = -0.04 to -0.03, and p < 0.00001) and SF-36 Survey (SMD = -5.86, CI = -6.28 to -5.44, and p < 0.00001) scales. There were no significant differences on the visual analog scale (VAS) when comparing duloxetine and gabapentin. Conclusions: Duloxetine appears to be effective in the management of DPN in different pain, symptom improvement, and quality of life scales.

Off-Target Effects of Antidepressants on Vascular Function and Structure

Depression emerges as a risk factor for cardiovascular disease, and it is thought that successful antidepressant treatment may reduce such a risk. Therefore, antidepressant treatment embodies a potential preventive measure to reduce cardiovascular events in patients with depression. Accumulating evidence indicates that antidepressants have off-target effects on vascular dysfunction and in the early stages of atherosclerosis, which form the basis for cardiovascular disease (CVD) pathogenesis. In this context, we performed a thorough review of the evidence pertaining to the effects of different classes of antidepressant medications on hemodynamic and early atherosclerosis markers. The preclinical and clinical evidence reviewed revealed a preponderance of studies assessing selective serotonin reuptake inhibitors (SSRI), whereas other classes of antidepressants are less well-studied. Sufficient evidence supports a beneficial effect of SSRIs on vascular inflammation, endothelial function, arterial stiffening, and possibly delaying carotid atherosclerosis. In clinical studies, dissecting the hypothesized direct beneficial antidepressant effect of SSRIs on endothelial health from the global improvement upon remission of depression has proven to be difficult. However, preclinical studies armed with appropriate control groups provide evidence of molecular mechanisms linked to endothelial function that are indeed modulated by antidepressants. This suggests at least a partial direct action on vascular integrity. Further research on endothelial markers should focus on the effect of antidepressants on treatment responders versus non-responders in order to better ascertain the possible beneficial vascular effects of antidepressants, irrespective of the underlying course of depression.

Urinary side effects of psychotropic drugs: A systematic review and metanalysis

OBJECTIVE

To evaluate the effects of psychotropic drugs on bladder function.

MATERIALS AND METHODS

A systematic review was carried out by searching PubMed and Embase databases for randomized controlled trials enrolling patients treated with psychotropic drugs with available information on treatment-related urinary disorders.

RESULTS

A total of 52 studies was selected. In antidepressant therapy, bladder voiding symptoms, rather than storage symptoms, were more frequently observed. Pooled analysis demonstrated a higher odds ratio (OR) of voiding  disorders in comparison with placebo (OR: 3.30; confidence interval [CI]: 1.90-5.72; 7856 participants; p < 0.001). Odds for voiding dysfunction was higher for tricyclic antidepressants and for Serotonin and Norepinephrine Reuptake Inhibitors (SNRIs) when compared to Selective Serotonin Reuptake Inhibitors (SSRIs). Treatment with antipsychotics was associated with heterogeneous urinary disorders  including emptying and storage disorders. OR for incontinence in patients with dementia taking  antipsychotics was higher than placebo (OR: 4.09; CI: 1.71-9.79, p = 0.002) with no difference between different atypical antipsychotics. Rate of voiding disorders was not different between conventional and atypical antipsychotics (OR: 1.64; CI: 0.79-3.39, p = 0.19), although quetiapine showed higher odds to cause voiding dysfunction than other atypical antipsychotics (OR: 2.14; CI: 1.41-3.26; p > 0.001).

CONCLUSIONS

In patients taking tricyclic antidepressants or SNRIs, bladder voiding disorders, could be the side effects of therapy rather than symptoms of a urological disease. Patients treated with these drugs should be actively monitored for the appearance of urinary symptoms. Antipsychotic treatment is associated with various urinary side effects requiring a tailored approach.

Extensive selective reporting of quality of life in clinical study reports and publications of placebo-controlled trials of antidepressants

BACKGROUND

Selective reporting of trial results is common.

OBJECTIVE

To study selective reporting in clinical study reports, company trial registers and publications of quality of life in placebo-controlled trials of antidepressants.

METHODS

We compared clinical study reports of four antidepressants (fluoxetine, duloxetine, paroxetine and sertraline) obtained from two European drug regulators, data from online company registers, and publications received or retrieved from Eli Lilly and GlaxoSmithKline. Pfizer was also contacted but did not provide any publications.

RESULTS

We included 15 trials (19,015 pages) and 4717 patients. Six trials had used SF-36, seven EQ-5D and two both instruments. Nine of the 15 CSRs (60%) displayed selective reporting. In the companies' online registers, there was selective reporting for all 15 trials (100%). We received 20 publications from Eli Lilly and retrieved six from the GlaxoSmithKline register. There was selective reporting in 24 of the 26 publications (92%). Despite extensive selective reporting, we found only small differences between placebo and active drugs.

CONCLUSIONS

Access to the full raw data from clinical trials and to case report forms for all patients are needed to evaluate the effect of antidepressants on quality of life. Regulatory agencies should refuse to approve drugs or new indications based on incomplete reporting.

The effects of comorbidity on the benefits and harms of treatment for chronic disease: a systematic review

Background

There are concerns about the potential for unintentional harms when clinical practice guidelines are applied to patients with multimorbidity. The objective was to summarize the evidence regarding the effect(s) of comorbidity on the outcomes of medication for an index chronic condition.

Methods

A systematic review was conducted of studies published in MEDLINE and Cochrane Trials before May 2012. The search strategy was constructed to identify articles indexed with “comorbidity” or a related term or by a given condition and one or more additional specified comorbid conditions. The search yielded 3252 articles, of which 37 passed the title/abstract screening process, and 22 were included after full-text review. An additional 23 articles were identified by screening the reference lists for included articles. Information was extracted on study design; population; therapy; comparison groups; outcome(s); main findings.

Findings

Indexing of articles was inconsistent, with no term for “multimorbidity,” and rare use of “comorbidity”. Only one article examined the effects of comorbidity per se, finding no benefit of tight control of DM among persons with high comorbidity, defined using a comorbidity index. The remainder examined pairs of conditions, the majority of which were post-hoc analyses of randomized controlled trials and which found no difference in outcomes according to whether a comorbid condition was present. Several demonstrated no difference or an increased risk of adverse outcome among persons with DM and tight control of HTN as compared to usual control. Several demonstrated lack of benefit of statins among persons with end-stage renal disease.

Conclusions

There is limited evidence regarding the effects of multiple comorbidities on treatment outcomes. The majority of studies demonstrated no effect of a single comorbid condition on outcomes. Additional studies examining a broad range of comorbidity are required, along with clear and consistent indexing to allow for improved synthesis of the evidence.

Milnacipran effects on 24-hour ambulatory blood pressure and heart rate in fibromyalgia patients: a randomized, placebo-controlled, dose-escalation study

OBJECTIVE

To characterize milnacipran effects on systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate (HR) in fibromyalgia patients using 24-hour ambulatory blood pressure monitoring (ABPM).

METHODS

This dose-escalation study included a 7-week double-blind treatment period and 2-week single-blind discontinuation period. Patients were randomized 2:1 to milnacipran (n = 210) or placebo (n = 111), with 50% of patients classified as 'hypertensive' at baseline (SBP ≥130 mmHg, DBP ≥85 mmHg, or current antihypertensive medication). Analyses were conducted at Weeks 4 and 7, after milnacipran dosages were escalated to 100 and 200 mg/day, respectively. Outcome measures included changes from baseline in mean ambulatory SBP, DBP, and heart rate for the 12-hour periods following the morning dose (post-AM dose) or evening dose (post-PM dose), and the entire 24-hour monitoring period. Primary outcome parameter was change from baseline in mean SBP for the 12-hour period post-AM dose. Safety analyses included adverse events and sitting vital sign readings taken at study visits.

RESULTS

Milnacipran increased ABPM vital signs at Week 4 (100 mg/day) and Week 7 (200 mg/day). Increases in the 12-hour period post-AM dose were similar at Weeks 4 and 7 (both visits: SBP and DBP, 4 to 5 mmHg; HR, 13 to 14 bpm). Mean increases in ambulatory vital signs were generally comparable between hypertensive and normotensive patients over 24-hour periods. Normal patterns of diurnal variation in blood pressure and heart rate were maintained in patients receiving milnacipran. Sitting vital signs were consistent with ABPM findings. Nausea was the most common adverse event observed with milnacipran.

CONCLUSIONS

Fibromyalgia patients receiving milnacipran in this ABPM study had mean increases in blood pressure and heart rate that were consistent with those observed in clinical efficacy trials. Diurnal variation was preserved and changes were not greater in hypertensive patients than in non-hypertensive patients. These findings cannot necessarily be generalized to other patient populations.

CLINICAL TRIAL REGISTRATION

This study was registered on clinicaltrials.gov (ID: NCT00618956).

Painful diabetic polyneuropathy: approach to diagnosis and management

OBJECTIVES

To provide a current overview of the diagnostic work-up and management of painful diabetic polyneuropathy (PDPN).

METHODS

A review covering the literature from 2004 to 2011, which describes the tools designed to diagnose neuropathic pain and assess its severity, including self-administered questionnaires, validated laboratory tests and simple handheld screening devices, and the evidence-based therapeutic approaches to PDPN.

RESULTS

The clinical aspects, pathogenesis, and comorbidities of PDPN, as well as its impact on health related quality of life (HR-QoL), are the main drivers for the management of patients with suspected PDPN. PDPN treatment consists first of all in improving glycemic control and lifestyle intervention. A number of symptomatic pharmacological agents are available for pain control: tricyclic antidepressants and selective serotonin norepinephrine reuptake inhibitors (venlafaxine and duloxetine), α2-delta ligands (gabapentin and pregabalin), opioid analgesics (tramadol and oxycodone), and agents for topical use, such as lidocaine patch and capsaicin cream. With the exception of transcutaneous electrical nerve stimulation, physical treatment is not supported by adequate evidence.

DISCUSSION

As efficacy and tolerability of current therapy for PDPN are not ideal, the need for a better approach in management further exists. Novel compounds should be developed for the treatment of PDPN.

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.

[Antidepressant therapy in coronary artery disease]

Depression is considered an independent risk factor for coronary artery disease (CAD) and other vascular conditions. Moreover, comorbid depressive disorder in CAD patients carries an increased risk of cardiac events and mortality. Among survivors of acute myocardial infarction, up to 20% meet diagnostic criteria for major depression, the presence of which carries a fivefold increased risk of cardiac death within 6 months. Heart patients with depressive comorbidity require particular care for both adequate treatment of their affective disorder and reduction of their cardiac risk. Antidepressant treatment must follow established guidelines; special care is needed to avoid cardiac side effects. In this review, we discuss the pathophysiological and prognostic significance of comorbid depression in CAD and weigh risks and benefits of available treatment options - particularly different drug classes and psychotherapy - in light of recent study results.

Efficacy of Duloxetine in Patients with Chronic Pain Conditions

The primary objective of this study is to review the efficacy of duloxetine in treating chronic pain using the Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT) recommendations for clinical significance across chronic pain states. These include pain intensity, patient ratings of overall improvement, physical functioning, and mental functioning. This review comprised the side-by-side analyses of 12 double-blind, placebo-controlled trials of duloxetine in patients with chronic pain (diabetic peripheral neuropathic pain, fibromyalgia, chronic pain due to osteoarthritis, and chronic low back pain). Patients received duloxetine (60 to 120 mg/day) or placebo. Average pain reduction was assessed over 3 months as the primary efficacy outcome. Other measures used were physical function and Patient Global Impression of Improvement. In 10 of the 12 studies, statistically significant greater pain reduction was observed for duloxetine- compared with placebo-treated patients. The response rates based on average pain reduction, improvement of physical function, and global impression were comparable across all 4 chronic pain states. Compared with patients on placebo, significantly more patients treated with duloxetine reported a moderately important pain reduction (≥30% reduction) in 9 of the 12 studies, a minimally important improvement in physical function in 8 of the 12 studies, and a moderately important to substantial improvement in Patient Global Impression of Improvement rating in 11 of the 12 studies. The analyses reported here show that duloxetine is efficacious in treating chronic pain as demonstrated by significant improvement in pain intensity, physical functioning, and patient ratings of overall improvement.

Duloxetine in the management of diabetic peripheral neuropathic pain

Diabetic neuropathy affects up to 70% of diabetics, and diabetic peripheral neuropathic pain (DPNP) is the most common and debilitating of the diabetic neuropathies. DPNP significantly reduces quality of life and increases management costs in affected patients. Despite the impact of DPNP, management is poor with one-quarter of patients receiving no treatment and many treated with medications having little or no efficacy in managing DPNP. Duloxetine is one of two drugs approved by the United States Food and Drug Administration for DPNP management. Duloxetine is a serotonin and norepinephrine reuptake inhibitor (SNRI) proven safe, effective, and cost-saving in reducing DPNP symptoms at a dose of 60 mg/day. Duloxetine doses greater than 60 mg/day for DPNP management are not recommended since they are no more efficacious and associated with more side effects; addition of pregabalin or gabapentin for these patients may be beneficial. Side effects of duloxetine are generally mild and typical for the SNRI class including nausea, dizziness, somnolence, fatigue, sweating, dry mouth, constipation, and diarrhea. Given its other indications, duloxetine is a particularly good choice for DPNP treatment in patients with coexisting depression, anxiety, fibromyalgia, or chronic musculoskeletal pain. Duloxetine treatment had no clinically significant effect on glycemic control and did not increase the risk of cardiovascular events in diabetes patients. However, duloxetine use should be avoided in patients with hepatic disease or severe renal impairment. Given its safety, efficacy, and tolerability, duloxetine is an excellent choice for DPNP treatment in many patients.

Effects of varying degrees of renal impairment on the pharmacokinetics of duloxetine: analysis of a single-dose phase I study and pooled steady-state data from phase II/III trials

BACKGROUND

Duloxetine is indicated for patients with a variety of conditions, and some of these patients may have mild to moderate degrees of renal impairment. Renal impairment may affect the pharmacokinetics of a drug by causing changes in absorption, distribution, protein binding, renal excretion or nonrenal clearance. As duloxetine is highly bound to plasma proteins and its metabolites are renally excreted, it is prudent to evaluate the effect of renal insufficiency on exposure to duloxetine and its metabolites in the systemic circulation.

OBJECTIVE

The aim of this study was to evaluate the effects of varying degrees of renal impairment on duloxetine pharmacokinetics in a single-dose phase I study and using pooled steady-state pharmacokinetic data from phase II/III trials.

METHODS

In the phase I study, a single oral dose of duloxetine 60 mg was given to 12 subjects with end-stage renal disease (ESRD) and 12 matched healthy control subjects. In the phase II/III trials (n = 463 patients), duloxetine 20-60 mg was given as once- or twice-daily doses. Duloxetine and metabolite concentrations in plasma were determined using liquid chromatography with tandem mass spectrometry. Noncompartmental methods (phase I: duloxetine and its metabolites) and population modelling methods (phase II/III: duloxetine) were used to analyse the pharmacokinetic data.

RESULTS

The maximum plasma concentration (C(max)) and the area under the plasma concentration-time curve (AUC) of duloxetine were approximately 2-fold higher in subjects with ESRD than in healthy subjects, which appeared to reflect an increase in oral bioavailability. The C(max) and AUC of two major inactive conjugated metabolites were as much as 2- and 9-fold higher, respectively, reflecting reduced renal clearance of these metabolites. Population pharmacokinetic results indicated that mild or moderate renal impairment, assessed by creatinine clearance (CL(CR)) calculated according to the Cockcroft-Gault formula, did not have a statistically significant effect on pharmacokinetic parameters of duloxetine. Values for the apparent total body clearance of duloxetine from plasma after oral administration (CL/F) in subjects with ESRD were similar to CL/F values in patients with normal renal function or with mild or moderate renal impairment.

CONCLUSION

Dose adjustments for duloxetine are not necessary for patients with mild or moderate renal impairment (CL(CR) > or =30 mL/min). For patients with ESRD or severe renal impairment (CL(CR) <30 mL/min), exposures of duloxetine and its metabolites are expected to increase; therefore, duloxetine is not generally recommended for these patients.

Duloxetine 60 mg/day for the prevention of depressive recurrences: post hoc analyses from a recurrence prevention study

OBJECTIVE

To assess the efficacy of duloxetine 60 mg/day in the prevention of depressive recurrence in patients with major depressive disorder (MDD).

METHODS

Patients having at least three episodes of MDD in the past 5 years received open-label (OL) duloxetine 60-120 mg/day for up to 34 weeks. Patients meeting response criteria were then randomised to either duloxetine or placebo for up to 52 weeks of double-blind maintenance treatment. Only patients taking duloxetine 60 mg/day during the OL phase, and randomised to either duloxetine (remained on 60 mg/day dose) or placebo, were included in this post hoc analysis. The primary outcome measure was time to recurrence of a major depressive episode. The 17-item Hamilton Rating Scale for Depression (HAMD(17)) was used to evaluate depressive symptomatology. Global and physical functioning and pain were also assessed. Safety and tolerability were assessed via analysis of treatment-emergent adverse events (TEAEs), vital signs and weight.

RESULTS

A total of 124 patients were randomised to duloxetine 60 mg/day (n = 64) or placebo (n = 60). Time to depressive recurrence was significantly longer in duloxetine-treated patients compared with placebo-treated patients (p = 0.001). During the double-blind maintenance phase, 31.7% of placebo-treated patients experienced a depressive recurrence compared with 12.5% of duloxetine-treated patients (p = 0.004). The HAMD(17) total score and most of its subscales as well as the Clinical Global Impression of Severity (CGI-S), significantly worsened in the placebo group compared with the duloxetine 60 mg/day group. There were no significant differences between treatment groups in TEAEs, discontinuations because of adverse events, vital signs or weight.

CONCLUSIONS

Treatment with duloxetine 60 mg/day was associated with a longer time to depressive recurrence and a significantly lower recurrence rate compared with placebo.