Long-term efficacy and safety of milnacipran compared to clomipramine in patients with major depression

Direct and indirect effects of psychopharmacological treatment on the cardiovascular system

Background Severe mental disorders, i.e. psychotic disorders, unipolar and bipolar disorders are associated with increased morbidity and mortality from cardiovascular and metabolic disorders. The underlying cause of this association is complex and comprises disorder specific alterations such as dysfunctions of immunological and hormonal systems, body-composition changes and health associated behaviors (smoking, sedentary lifestyle, alcohol intake and treatment compliance). Furthermore, some psychopharmacological drugs may exert unwanted side effects that impact the cardiovascular system. Methods This paper reviews studies concerning commonly used antidepressant and antipsychotics drugs with a particular focus on direct and indirect cardiovascular side effects. Results Newer antidepressant drugs have a favorable cardiovascular safety profile compared to tricyclic antidepressants. However, QTc prolongation, increased blood pressure and potentially higher risks of bleeding have been observed in some newer antidepressants. Some second generation (atypical) antipsychotics have raised concern because of indirect cardiovascular, metabolic side effects such as weight gain and disturbances in lipid and glucose metabolism. Conclusions Psychiatrists need to be aware of potential direct and indirect cardiovascular side effects and to include them in the risk/benefit assessment when choosing a specific individualized treatment.

Consensus statements on the clinical understanding and use of milnacipran in Hong Kong

OBJECTIVE

Our aim is to develop a local consensus to guide medical practitioners and psychiatrists on the use of milnacipran in different psychiatric conditions.

METHODS

By utilizing the modified Delphi technique, 12 statements were electronically voted on anonymously for their practicability of recommendation.

RESULTS

There was a very high degree of agreement among the consensus group on 10 finalized consensus statements, but 2 statements were voted down due to a poor degree of agreement.

CONCLUSIONS

The present consensus statements were developed as general recommendations for medical practitioners and psychiatrists to be practically referred to in clinical settings.

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.

Epidemiologic Evaluation of Cardiovascular Risk in Patients Receiving Milnacipran, Venlafaxine, or Amitriptyline: Evidence from French Health Data

BACKGROUND:

Milnacipran, a selective serotonin and norepinephrine reuptake inhibitor, is approved by the Food and Drug Administration for the management of fibromyalgia. It has been available for many years in several countries outside the US for the treatment of depression.

OBJECTIVE:

To conduct population-based analyses comparing the risk of serious cardiovascular (CV) events (eg, acute myocardial infarction, stroke, congestive heart failure) associated with treatment with milnacipran compared with venlafaxine and amitriptyline, 2 other commonly prescribed drugs that also inhibit reuptake of norepinephrine and serotonin.

METHODS:

Information from the French Thales electronic health record database from 2001 to 2007 was used. Patients with 1 or more prescriptions for milnacipran, venlafaxine, or amitriptyline; 180 or more days of continuous eligibility prior to the first prescription; and no prior CV event diagnoses during the 180-day baseline period were included. A retrospective, matched-cohort design was employed. The incidence rates of CV events between cohorts receiving milnacipran, venlafaxine, and amitriptyline were compared using unadjusted incidence rate ratio (IRR) and adjusted conditional IRR based on Poisson regression.

RESULTS:

We identified 4452 milnacipran-venlafaxine and 3761 milnacipran-amitriptyline matched pairs. The matched cohorts had similar baseline characteristics. The unadjusted IRRs of any CV events, comparing milnacipran with venlafaxine or amitriptyline, were 1.02 (95% CI 0.73 to 1.44) and 1.30 (95% CI 0.90 to 1.89), respectively. Adjusted IRRs confirmed the statistical similarity in the CV event risk between milnacipran and venlafaxine (adjusted IRR = 1.29, 95% CI 0.76 to 2.17) or amitriptyline (adjusted IRR = 1.06, 95% CI 0.59 to 1.89).

CONCLUSIONS:

This French population-based study found that the risk of CV events was not significantly different for patients receiving milnacipran versus those receiving venlafaxine or amitriptyline.

In vivo studies of effects of antidepressants on parotid salivary secretion in the rat

Tricyclic antidepressants (TCA) are well-known xerogenic drugs, while antidepressants such as selective serotonin reuptake inhibitors (SSRI) are considered less xerogenic. The antimuscarinic effect of the TCAs has been considered to be the principal mechanism causing a dry mouth. Although the muscarinic receptor is commonly targeted by xerogenic pharmaceuticals, the salivation reflex arc may be affected at other levels as well. We currently wondered whether or not antidepressants exert an inhibition of the salivary reflex not only at the glandular level but at a central level as well. In this study, the effects of a TCA (clomipramine), a SSRI (citalopram) and a serotonin-noradrenaline reuptake inhibitor (SNRI; venlafaxine) were examined on reflex- (0.5M citric acid applied on the tongue) and methacholine-evoked salivary secretion. While all three compounds inhibited citric acid-evoked secretion (-40 to -60% at 5mg/kg i.v. of the antidepressants), only clomipramine inhibited methacholine-evoked secretion (-30% at 5mg/kg i.v.). On the contrary, both citalopram and venlafaxine increased the methacholine-evoked secretion (+44 to 49%). This was particularly obvious for the salivary protein output (>200%). In the presence of α- and β-adrenoceptor antagonists, the citalopram- and venlafaxine-induced increases were reduced. Thus, antidepressants irrespective of type may exert xerogenic effects by inhibiting the salivary reflex in the central nervous system. However, while TCAs may also hamper the secretory response by antimuscarinic effects, the SSRI and the SNRI groups of pharmaceuticals seem to lack this additional xerogenic mechanism indicating a better therapeutic profile and better opportunities for pharmacological treatment of drug-induced xerostomia.

Open-label milnacipran for patients with persistent knee pain 1 year or longer after total knee arthroplasty: a pilot study

OBJECTIVE

The current study investigates whether milnacipran is effective in reducing pain and improving function in patients with persistent pain ≥ 1 year after total knee arthroplasty.

METHOD

This was a 12-week open-label study of flexibly dosed milnacipran in patients (N = 5) experiencing chronic persistent knee pain ≥ 1 year following total knee arthroplasty in the absence of new injury, infection, or implant failure. Subjects were identified from October 2010 to August 2011 through the Duke University Medical Center orthopedic clinic (Durham, North Carolina), typically during 1-year postoperative follow-up visits, and were referred by their orthopedic surgeon.

RESULTS

Milnacipran treatment was associated with reduction in pain according to the primary outcome measure of the visual analog scale (VAS) score for pain (effect size of 1.15) and secondary outcome measures of Knee Society Score (KSS) evaluation subscale score (effect size of 1.37) and Medical Outcomes Study 36-item Short-Form Health Survey (SF-36) bodily pain subscale (effect size of 1.16) at week 12. Secondary outcome measures of functional change were mixed in such that, at week 12, the SF-36 physical functioning subscale showed improvement (effect size of 1.16), but the KSS function subscale score was just below the threshold for meaningful effect size (0.98).

CONCLUSIONS

Open-label milnacipran demonstrated reduced pain and some evidence of functional improvement in this small sample of patients with chronic persistent pain 1 year or more after total knee arthroplasty such that well-powered studies are warranted.

A 10-month, open-label evaluation of desvenlafaxine in outpatients with major depressive disorder

BACKGROUND

The primary objective was to evaluate the long-term safety of desvenlafaxine (administered as desvenlafaxine succinate) during open-label treatment in adult outpatients with a primary DSM-IV diagnosis of major depressive disorder (MDD).

METHOD

Depressed adult outpatients (≥ 18 years) who had completed 8-week, double-blind therapy (desvenlafaxine, venlafaxine extended release, or placebo) in a phase 3 study of desvenlafaxine for MDD received up to 10 months of open-label treatment with flexible-dose desvenlafaxine (200 to 400 mg/d). Safety assessments included physical examination, measurement of weight and vital signs, laboratory determinations, and 12-lead electrocardiogram recordings. Adverse events (AEs) and discontinuations due to AEs were monitored throughout the trial. The primary efficacy outcome was mean change from baseline on 17-item Hamilton Depression Rating Scale (HDRS-17) total score. The trial was conducted from August 2003 to March 2006.

RESULTS

The safety population included 1,395 patients who took at least 1 dose of open-label desvenlafaxine. Treatment-emergent AEs were reported by 1,238 of 1,395 patients (89%) during the open-label, on-therapy period. Treatment-emergent AEs reported by 10% or more patients were headache, nausea, hyperhidrosis, dizziness, dry mouth, insomnia, upper respiratory infection, nasopharyngitis, and fatigue. Adverse events were the primary reason for study discontinuation in 296 of 1,395 patients (21%). Ten patients (< 1%) had serious AEs that were considered possibly, probably, or definitely related to the study drug during the on-therapy period. No deaths occurred during the study.

CONCLUSIONS

Desvenlafaxine can be safely administered for up to 12 months. No new safety findings were observed in this study.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT01309542.

Milnacipran: beyond a role of antidepressant

Milnacipran is a serotonin and norepinephrine reuptake inhibitor (SNRI) with negligible effects on any presynaptic or postsynaptic receptors. Milnacipran has unique pharmacokinetic and pharmacodynamic characteristics that distinguish it from the other marketed serotonin and norepinephrine reuptake inhibitors, venlafaxine, desvenlafaxine, and duloxetine such as equipotent serotonin and norepinephrine reuptake inhibition and a linear dose-concentration trend at therapeutic doses. The half-life of milnacipran is approximately 8 hours. In addition, milnacipran does not inhibit the cytochrome P 450 system, indicating minimal propensity for drug-drug interactions. The antidepressant efficacy of milnacipran has been clearly established in a number of randomized, double-blind, placebo-controlled clinical trials, and it has been widely used for treating major depressive disorder. Moreover, evidence suggests that milnacipran is effective and tolerable in the treatment of fibromyalgia and may have usefulness for fatigue and anxiety symptoms. The current paper reviews researches conducted to date that is relevant to the efficacy, tolerability, and mechanism of action of milnacipran in the treatment of depression, fibromyalgia, and other psychiatric syndromes. Future directions of research are also identified.

Milnacipran versus other antidepressive agents for depression

BACKGROUND

Although pharmacological and psychological interventions are both effective for major depression, antidepressant drugs are frequently used as first-line treatment in primary and secondary care settings. Milnacipran, a dual serotonin-norepinephrine reuptake inhibitor (SNRI), is one of the antidepressant drugs that clinicians use for routine depression care.

OBJECTIVES

To assess the evidence for the efficacy, acceptability and tolerability of milnacipran in comparison with tricyclic antidepressants (TCAs), heterocyclics, SSRIs and other newer antidepressive agents in the acute-phase treatment of major depression.

SEARCH STRATEGY

The Cochrane Collaboration Depression, Anxiety & Neurosis review group Controlled Trials Register (CCDANCTR-Studies and CCDANCTR-References) were electronically searched in August 2008. References of relevant trials and other reviews were also checked. Trial databases of the drug-approving agencies and ongoing clinical trial registers for all published and unpublished trials were hand-searched in 2007. All relevant authors were contacted for supplemental data. No language restriction was applied.

SELECTION CRITERIA

Randomised controlled trials comparing milnacipran with any other active antidepressive agents (including non-conventional agents such as herbal products like hypericum) as monotherapy in the acute phase of major depression were selected.

DATA COLLECTION AND ANALYSIS

Two reviewers independently checked eligibility, assessed methodological quality and extracted data from the eligible trials using a standardised data extraction form. The number of participants who responded to treatment or those who achieved remission were calculated on an intention-to-treat basis. Random-effects meta-analyses were conducted, combining data from the included trials.

MAIN RESULTS

A total of 16 randomised controlled trials (n=2277) were included in the meta-analysis.Despite the size of this sample, the pooled 95% confidence intervals were rather wide and there were no statistically significant differences in efficacy, acceptability and tolerability when comparing milnacipran with other antidepressive agents. However, compared with TCAs, patients taking milnacipran were associated with fewer dropouts due to adverse events (OR 0.55; 95%CI 0.35 to 0.85). There was also some weak evidence to suggest that patients taking milnacipran experienced fewer adverse events of sleepiness/ drowsiness, dry mouth or constipation compared with TCAs.

AUTHORS' CONCLUSIONS

Currently, there is inadequate evidence to conclude whether milnacipran is superior, inferior or the same as other antidepressive agents in terms of efficacy, acceptability and tolerability in the acute phase treatment of major depression. However, there is some evidence in favour of milnacipran over TCAs in terms of dropouts due to adverse events (acceptability) and the rates of experiencing adverse events (tolerability). Information about other clinically meaningful outcomes such as cost-effectiveness and social functioning, including the ability to return to work, is lacking. Further study is needed to answer whether milnacipran would be the better choice of antidepressant for acute major depression.

Efficacy and tolerability of milnacipran in the treatment of major depression in comparison with other antidepressants : a systematic review and meta-analysis

BACKGROUND

Milnacipran, a dual serotonin-noradrenaline reuptake inhibitor, is one of the newer antidepressants that clinicians use for the routine care of patients with major depression. We undertook a systematic review and meta-analysis of randomized controlled trials that compared the efficacy and tolerability of milnacipran with other antidepressants.

OBJECTIVE

To assess the efficacy and tolerability of milnacipran in comparison with TCAs, SSRIs and other drugs in the acute phase of treatment for major depression.

METHODS

We searched the Cochrane Collaboration Depression, Anxiety and Neurosis Controlled Trials registers, journals, conference proceedings, trial databases of the drug-approving agencies and ongoing clinical trial registers for all published and unpublished randomized controlled trials that compared the efficacy and adverse events of milnacipran versus any other antidepressant. The search was conducted in December 2006 and updated in May 2007. No language restrictions were applied. All relevant authors were contacted to supplement any incomplete reporting in the original papers. Randomized controlled trials comparing milnacipran with any other active antidepressants as monotherapy in the acute phase of treatment for major depression were selected. Participants were aged > or =18 years, of both sexes and with a primary diagnosis of unipolar major depression. Studies were excluded when the participants had specific psychiatric and medical co-morbidities. Two independent reviewers assessed the quality of trials for inclusion, and subsequently extracted data. Disagreements were resolved by consensus. Meta-analyses were conducted for efficacy and tolerability outcomes. Sixteen randomized controlled trials (n = 2277) were included in the meta-analyses.

RESULTS

No differences were found in achieving clinical improvement, remission or overall tolerability when comparing milnacipran with other antidepressants. However, compared with the TCAs, fewer patients taking milnacipran were early treatment withdrawals due to adverse events (number needed to harm (NNH) = 15; 95% CI 10, 48). Significantly more patients taking TCAs experienced adverse events compared with milnacipran (NNH = 4; 95% CI 3, 7).

CONCLUSIONS

The overall effectiveness and tolerability of milnacipran versus other antidepressants does not seem to differ in the acute phase of treatment for major depression. However, there is some evidence in favour of milnacipran over TCAs in terms of premature withdrawal due to adverse events and the rates of patients experiencing adverse events. Milnacipran may benefit some patient populations who experience adverse effects from other antidepressants in the acute phase of treatment for major depression.

Duloxetine for the management of diabetic peripheral neuropathic pain: evidence-based findings from post hoc analysis of three multicenter, randomized, double-blind, placebo-controlled, parallel-group studies

OBJECTIVE

This post hoc analysis was aimed to summarize the efficacy and tolerability of duloxetine as represented by number needed to treat (NNT) and number needed to harm (NNH) to provide a clinically useful assessment of the position of duloxetine among current agents used to treat diabetic peripheral neuropathic pain (DPNP).

METHODS

Data were pooled from three 12-week, multicenter, randomized, double-blind, placebo-controlled, parallel-group studies in which patients received 60 mg duloxetine either QD or BID or placebo. NNT was calculated based on rates of response (defined as >or=30% and >or=50% reductions from baseline in the weekly mean of the 24-hour average pain severity scores); NNH was calculated based on rates of discontinuation due to adverse events (AEs).

RESULTS

Patients receiving duloxetine 60 mg QD and 60 mg BID had NNTs (95% CI) of 5.2 (3.8-8.3) and 4.9 (3.6-7.6), respectively, based on last observation carried forward; NNTs of 5.3 (3.8-8.3) for 60 mg QD and 5.7 (4.1-9.7) for 60 mg BID were obtained based on baseline observations carried forward. The NNHs (95% CI) based on discontinuation due to AEs were 17.5 (10.2-58.8) in the duloxetine 60-mg QD group and 8.8 (6.3-14.7) in the 60-mg BID group.

CONCLUSION

These post hoc results suggest that duloxetine was effective and well tolerated for the management of DPNP and further support the importance of duloxetine as a treatment option for clinicians and patients to assist with the management of DPNP.

A comparative meta-analysis of Clinical Global Impressions change in antidepressant trials

Two scales of the Clinical Global Impressions (CGI) Scale are frequently used in antidepressant trials. No research has systematically addressed how CGI change compares to change on established measures such as the Hamilton Depression Rating Scale (HAM-D), Montgomery-Asberg Depression Rating Scale, or Beck Depression Inventory. The current meta-analysis examined 75 antidepressant trials in which the CGI was used along with at least one other popular depression measure. The CGI-Severity scale was significantly more conservative than the HAM-D in rating change in double-blind trials, but not in open trials. The Beck Depression Inventory was significantly more conservative than the CGI-Severity. The CGI-Improvement scale was significantly more liberal than the HAM-D or Montgomery-Asberg Depression Rating Scale. Rater bias or scale content may explain differences between measures. Given the often substantial differences between instruments, researchers should use a variety of measures rather than relying on any single tool in assessing treatment response.

Remission, dropouts, and adverse drug reaction rates in major depressive disorder: a meta-analysis of head-to-head trials

OBJECTIVE

To summarize remission rates and dropouts due to adverse drug reactions (ADRs) or lack of efficacy (LoE) of serotonin-norepinephrine reuptake inhibitors (SNRIs), selective serotonin-reuptake inhibitors (SSRIs), and tricyclic antidepressants (TCAs) in treating major depressive disorder.

METHODS

We searched MEDLINE, EMBASE, IPA, and the Cochrane International Library from 1980-2005. Meta-analysis summarized outcomes from head-to-head randomized clinical trials comparing >or= 2 drugs from three antidepressants classes (SNRIs, and/or SSRIs, and/or TCAs) followed by >or= 6 weeks of treatment. Remission was a final Hamilton Depression Rating Scale (HAMD) score <or= 7 or Montgomery-Asberg Depression Rating Scale (MADRS) <or= 12. Intent-to-treat data were combined across study arms using random effects models, producing point estimates with 95% confidence intervals.

RESULTS

We obtained data from 30 arms of 15 head-to-head trials with 2458 patients. SNRIs had the highest ITT remission rate (49.0%), then TCAs (44.1%), and SSRIs (37.7%) (p > 0.05 for SNRIs versus TCAs; p < 0.001 for TCAs versus SSRIs and SNRIs versus SSRIs). When categorized as inpatients (n = 582) and outpatients (n = 1613), SNRIs had the highest remission rates (52.0% for 144 inpatients and 49.3% for 559 outpatients). SNRIs had lowest overall dropouts (26.1%), followed by SSRIs (28.4%), and TCAs (35.7%). Dropouts due to ADRs and LoE were 10.3% and 6.2% for SNRIs, 8.3% and 7.2% for SSRIs, and 19.8% and 9.9% for TCAs, respectively (p > 0.05 for ADR dropouts only). One limitation was the inclusion of only venlafaxine-XR; results may not be the same for immediate release forms. In addition, few studies reported remission rates.

CONCLUSIONS

SNRIs had the highest efficacy remission rates (statistically significant for inpatients and outpatients), and the lowest overall dropout rates, suggesting clinical superiority in treating major depression.

Duloxetine: A balanced and selective norepinephrine- and serotonin-reuptake inhibitor

PURPOSE

The pharmacology, pharmacokinetics, efficacy, safety, drug interactions, dosage and administration, cost, and place in therapy of duloxetine for major depression, pain from diabetic peripheral neuropathy, and stress urinary incontinence are reviewed.

SUMMARY

Duloxetine is a balanced selective serotonin and norepinephrine-reuptake inhibitor available in the United States for the treatment of major depressive disorder (MDD) and diabetic peripheral neuropathic pain (DPNP). Duloxetine has also been used for the treatment of stress urinary incontinence (SUI). Absorption of duloxetine begins two hours after oral administration, reaching a maximum plasma concentration in six hours. Half-life and volume of distribution are 12 hours and 1640 L, respectively. The recommended dosage of duloxetine is 40-80 mg daily, depending on the indication, preferably split into two doses per day. For the treatment of major depression, duloxetine has achieved remission rates similar to that of existing selective serotonin-reuptake inhibitors (SSRIs). For SUI and pain associated with diabetic peripheral neuropathy, duloxetine has not demonstrated equivalence or superiority to existing therapies. The adverse effects of duloxetine are similar to those of traditional SSRIs. Nausea is common and has been cited as the primary reason for discontinuation of duloxetine in trials. Increases in blood pressure have been mild, but caution should be used in patients with hypertension. Patients with a creatinine clearance of <30 mL/min and patients with hepatic impairment should avoid duloxetine. Duloxetine should not be recommended as first-line therapy for SUI or DPNP. For MDD, duloxetine may be a useful alternative for patients who do not benefit from or are unable to tolerate other antidepressant therapy.

CONCLUSION

Duloxetine has been approved for the treatment of MDD and pain associated with diabetic peripheral neuropathy in adults.

Antidepressants and seizures: emphasis on newer agents and clinical implications

Seizures are a known, relatively rare, consequence of antidepressant treatment. Risk estimates vary depending on the study, source of data and patient population, predisposed vs. nonpredisposed. For newer antidepressants (e.g. selective serotonin reuptake inhibitors, bupropion, mirtazepine, etc.), the risk is generally considered to be low (0.0%-0.4%) and not very different from the incidence of first seizure in the general population (0.07%-0.09%). Risk with tricyclic antidepressants at effective therapeutic doses is relatively high (0.4% to 1-2%). Seizure following overdose is a significant and relatively frequent event for some antidepressants. Patients being considered for antidepressant treatment should be screened for predisposition to seizures. Predisposed patients should receive antidepressants cautiously. The seizure potential of antidepressants in patients without a predisposition is low, especially for newer antidepressants. Seizure risk, along with other drug-related considerations, e.g. weight gain, sexual dysfunction and sedation, should be considered when prescribing an antidepressant.

Effect of milnacipran on extracellular monoamine concentrations in the medial prefrontal cortex of rats pre-treated with lithium

Antidepressants are effective in most patients with depression, but sometimes have sub-optimal effects. Thus, there is a need to use more powerful antidepressants when dealing with treatment-resistant cases. Lithium carbonate is widely used for this purpose. We investigated the acute effects of milnacipran, a serotonin-noradrenaline reuptake inhibitor, on extracellular serotonin, dopamine and noradrenaline concentrations, in the rat medial prefrontal cortex. The effects of milnacipran were examined in rats following 7 days of treatment with lithium, and in untreated controls. The lithium group had significantly greater basal levels of extracellular serotonin than the control group. Milnacipran (3 mg/kg) combined with lithium treatment caused a greater increase in extracellular noradrenaline and dopamine levels than milnacipran alone. Milnacipran (3 and 30 mg/kg) combined with lithium treatment also caused a greater increase in extracellular serotonin levels than milnacipran alone. Thus, lithium might augment the antidepressant effects of serotonin-noradrenaline reuptake inhibitors by augmenting serotonin release.

Radiotherapy-induced salivary dysfunction

Dry mouth (xerostomia) is one of the most common complaints following radiation therapy (RT) for head and neck cancers. Notably, RT causes irreparable damage to salivary glands that increases the risk for severe and long-term oral and pharyngeal disorders. Several strategies in the treatment of head and neck cancers have been developed to prevent RT-induced salivary dysfunction while providing definitive oncologic therapy. These include salivary-sparing RT; cytoprotectants (such as amifostine); combination therapy of high-dose-rate intraoperative RT, external beam RT, plus a cytoprotectant; salivary gland surgical transfer; and gene therapy. Future research that incorporates biologic, pharmacologic, and technologic advancements that optimize therapeutic ratios and minimizes adverse oral sequelae is warranted.

A randomised, double-blind comparison of milnacipran and imipramine in the treatment of depression

This multicentre, double-blind, randomised trial in 109 patients compared the efficacy and tolerance of the novel selective serotonin and noradrenaline reuptake inhibitor (SNRI) antidepressant milnacipran (50 mg twice daily, n=53) with the established tricyclic agent imipramine (75 mg twice daily, n=56) over a period of 6 weeks, in patients with major depression (Montgomery-Asberg depression rating score (MADRS) > or =25). Initiation of antidepressant medication was conducted during a 2-week period of hospitalisation, after a 3- to 7-day washout period. Concomitant psychiatric medication was limited to lorazepam, cyamemazine, chloral hydrate and long-term uncomplicated lithium therapy. Assessment for efficacy using the MADRS and Hamilton rating scales of depression, a visual analogue scale and global evaluation revealed both agents to be highly effective (P=0.0001) in this group of patients. Milnacipran was found to be of similar efficacy to imipramine. Tolerance, assessed by physiological and biochemical examinations with routine inventory and spontaneous report of adverse events, revealed a clear advantage for milnacipran. The incidence of anticholinergic events with milnacipran was about half that with imipramine and the overall incidence of adverse events by either reporting method was markedly lower with milnacipran than with imipramine. Furthermore, the patient drop-out rate with imipramine was double that experienced with milnacipran. Milnacipran appears to possess equal antidepressant efficacy to imipramine but with markedly superior tolerance. Therefore, milnacipran constitutes an important new treatment option in major depression.

Xerostomia and the geriatric patient

Saliva is essential for the preservation of oral-pharyngeal health, and disorders of salivary physiology are associated with numerous oral and pharyngeal problems, particularly in older people. Although salivary function is remarkably intact in healthy aging, medical problems, medications, and head and neck radiotherapy can cause salivary dysfunction and complaints of xerostomia among older people. Sjögren's syndrome, an autoimmune exocrinopathy, is the most common medical disease associated with salivary dysfunction. Medications with anticholinergic side effects will impair salivary output, and head and neck radiotherapy for cancer will cause permanent destruction of salivary glands. Treatments for salivary problems are based upon establishing a diagnosis, protecting oral and pharyngeal health, stimulating remaining glands, and replacing lost salivary fluids.

Milnacipran: an antidepressant with dual selectivity of action on noradrenaline and serotonin uptake

Milnacipran is a new antidepressant which possesses potent and doubly selective action in that it inhibits both the re-uptake of serotonin and noradrenaline without any effect on other neurotransmitter systems. The almost equipotent inhibition of serotonin and noradrenaline by milnacipran is functionally reflected in the several-fold and long-lasting increase of the levels of these monoamines in the brain and in antidepressant-like effects in animals. In man, milnacipran distinguishes itself from many other antidepressants by its simple pharmacokinetics. It shows linear dose-concentration relationship over a dose range of 25-200 mg/day. It is rapidly and extensively absorbed and almost completely eliminated after 12 h (t1/2 approx. 8 h). Steady-state plasma levels are reached within 32-48 h after twice daily oral administration. Milnacipran is highly bioavailable (>85 per cent) and its metabolism does not involve the cytochrome P450 enzyme system. In clinical studies, milnacipran showed antidepressant efficacy similar to that of TCAs and SSRIs and superior to that of placebo. At the optimum dose of 100 mg/day, after 4-8 weeks of treatment, 60-64 per cent of in- or out-patients with major depression improve (>/=50 per cent reduction of HAMD and MADRS score) and about 32-39 per cent of them achieve full remission (HAMD score</=7). Milnacipran has proved to be a very safe drug with a benign adverse event profile clearly superior to that of TCAs and, to a certain extent, that of SSRIs. Only about 10 per cent of patients experience side-effects and only dysuria occurred more frequently (2 per cent) with milnacipran than with TCAs or SSRIs. Milnacipran appears therefore to be an antidepressant with a very favourable benefit/risk ratio. Copyright 2000 John Wiley & Sons, Ltd.

Psychopharmacology of depression in the next millennium

Over the last half of the 20th century, there have been a series of psychopharmacologic strategies for treatment of depression. As we approach the next century, new therapies in varying stages of American release are being developed. This review will focus on information available for the following proposed antidepressants: 1) reboxetine, a norepinephrine selective reuptake inhibitor; 2) milnacipran, a combined serotonin/norepinephrine reuptake inhibitor; 3) a new enantiomer of fluoxetine, a selective serotonin reuptake inhibitor; 4) duloxetine, another combined serotonin/norepinephrine reuptake inhibitor; 5) sunepitron, a combined 5-HT1A agonist and a2 antagonist; and 6) MK-869, a substance P inhibitor. Finally, other possible developing directions will be reviewed, including corticotropin-releasing factor.