Does pain cause the perception of fatigue in patients with chronic pain? Findings from studies for management of diabetic peripheral neuropathic pain with duloxetine.

A major issue in pain literature is whether an etiological association between pain, sleep, and vitality exists. We utilized data from clinical trials of duloxetine for management of diabetic peripheral neuropathic pain (DPNP) to investigate these associations. Data were pooled from 3 double-blind, randomized, placebo-controlled, 12-week trials of patients without mood disorder (N = 1,139). After excluding 442 patients who reported maximum vitality at baseline, experienced treatment-emergent somnolence, asthenia or fatigue, or were taking sedating concomitant medications or duloxetine 20 mg/day, 697 were included in the analysis. Efficacy measures included weekly mean scores for average daily and night pain, pain interference with sleep, and vitality. Baseline to end point mean improvements in daily and night pain, Brief Pain Inventory sleep interference, and vitality were significantly superior for duloxetine compared with placebo (P < or = 0.001). Correlations between changes in daily and night pain, and sleep interference with vitality changes were -0.34, -0.32, and -0.28, respectively (P < 0.001). The direct effect of treatment on change in vitality was statistically significant (68%, P = 0.010) when assessed in an indirect manner through change in sleep interference alone but not in daily or night pain solely. Path analyses suggested vitality improvement in patients with chronic pain may be secondary to improvement in pain by duloxetine. Results do not prove pain causes fatigue, but indicate in DPNP patients with fatigue that treatment of pain can improve perception of improvement in fatigue. Thus, improvement of pain may be important in the context of trying to improve fatigue in DPNP patients.

Switching patients from daily citalopram, paroxetine, or sertraline to once-weekly fluoxetine in the maintenance of response for depression.

BACKGROUND: Major depressive disorder is frequently a chronic, recurrent condition necessitating maintenance treatment. For some patients, compliance with daily pharmacotherapy is difficult over time. As an alternative approach, a once-weekly administered formulation of fluoxetine has recently been made available. This raises the important question of whether once-weekly enteric-coated fluoxetine, 90 mg, is effective for maintenance of response in patients whose depressive symptoms have responded to daily dosing with selective serotonin reuptake inhibitors (SSRIs) such as citalopram, paroxetine, or sertraline. METHOD: Patients had met DSM-IV criteria for major depressive disorder prior to beginning treatment for their current episode, had received 6 to 52 weeks of treatment with citalopram (20-40 mg/day [N = 83]), paroxetine (20 mg/day [N = 77]), or sertraline (50-100 mg/day [N = 86]), and had responded to that treatment (Clinical Global Impressions-Severity of Illness [CGI-S] score < or = 2, modified 17-item Hamilton Rating Scale for Depression [HAM-D-17] score < or = 10). Patients meeting these criteria (N = 246) continued treatment with their current SSRI for 1 week, then were switched to open-label enteric-coated fluoxetine, 90 mg, taken once weekly for 12 weeks. Safety measures were comparisons of spontaneously reported and solicited treatment-emergent adverse events. Efficacy measures were percentages of patients who discontinued the study for relapse and lack of efficacy and comparison of change from baseline to endpoint in scores on the modified HAM-D-17, subscales of the HAM-D-28, and the CGI-S. Quality of life measures were assessed with the MOS 36-Item Short-Form Health Survey (SF-36). We hypothesized that the once-weekly administration of fluoxetine could be safely and effectively initiated among subjects who had been stabilized on daily SSRI treatment. RESULTS: Seventy-nine percent of patients successfully completed a switch to enteric-coated fluoxetine, 90 mg, with 9.3% discontinuing due to relapse or lack of efficacy. Enteric-coated fluoxetine at a once-weekly dose of 90 mg was well tolerated in all groups. No significant increases were found in the HAM-D-17 total, HAM-D-28 subscores, or CGI-S score. Patients showed improvement from baseline to endpoint in most of the SF-36 health concepts. CONCLUSION: Enteric-coated fluoxetine taken once weekly appears to be well tolerated and efficacious in patients who responded to acute therapy with other SSRIs and were subsequently switched to fluoxetine once weekly for continuation/maintenance therapy.

Weekly luteal-phase dosing with enteric-coated fluoxetine 90 mg in premenstrual dysphoric disorder: a randomized, double-blind, placebo-controlled clinical trial.

BACKGROUND: Because the symptoms of premenstrual dysphoric disorder (PMDD) are limited to the luteal phase of the menstrual cycle, the potential benefit of luteal-phase dosing has been hypothesized. OBJECTIVE: This multicenter, randomized, double-blind, placebo-controlled, parallel-group trial evaluated the efficacy and tolerability of enteric-coated fluoxetine 90 mg given once or twice during the luteal phase for the treatment of PMDD. METHODS: Study drug was given 14 and 7 days before expected menses during the luteal phase of 3 menstrual cycles. After a screening period and single-blind placebo lead-in period, eligible women were randomized to I of 3 treatment groups: enteric-coated fluoxetine 90 mg on both days (LPWDx2); placebo 14 days before menses and enteric-coated fluoxetine 90 mg 7 days before menses (LPWDx1); or placebo on both days (PLC). The primary efficacy measure was change from baseline in mean luteal-phase scores on the Daily Record of Severity of Problems (DRSP). Secondary efficacy measures included scores on the Rating Scale for Premenstrual Tension Syndrome, Clinician-Rated (PMTS-C); the Clinical Global Impression (CGI)-Severity scale; and the Patient Global Impression (PGI)-Improvement scale. Quality of life was assessed using the Sheehan Disability Scale. RESULTS: Two hundred fifty-seven women were randomized to treatment. At the end of the study, the LPWDx2 group had statistically significant improvements in DRSP total, DRSP mood subtotal, DRSP social functioning subtotal, PMTS-C, CGI-Severity, PGI-Improvement, and Sheehan Disability Scale work and family life scores compared with LPWDx1 and PLC (each measure, P < 0.05). There was also a statistically significant improvement in the score on the social life section of the Sheehan Disability Scale with LPWDx2 compared with PLC (P = 0.037). Across all treatment groups, 5 patients discontinued due to nonserious adverse events. Rates of discontinuation for any reason did not differ between the 3 treatment groups. CONCLUSION: The findings of this study support the efficacy and tolerability of enteric-coated fluoxetine 90 mg given twice during the luteal phase of the menstrual cycle for the treatment of PMDD.

Does pain mediate the pain interference with sleep problem in chronic pain? Findings from studies for management of diabetic peripheral neuropathic pain with duloxetine.

Although sleep problems are common in patients with chronic pain, it is unclear whether pain mediates (causes) impaired sleep. The relationship between pain and sleep has been difficult to investigate because of the potential confounds of depression and somnolence. This report used clinical trials data for duloxetine in the management of diabetic peripheral neuropathic pain (DPNP) to investigate the direction of this association. Data were pooled from three double-blind, randomized, placebo-controlled, 12-week trials of patients with DPNP without mood disorder (n=1,139). DPNP patients reporting somnolence and those who were receiving sedating concomitant medications were removed from the analyses (n=93). Efficacy measures included weekly mean scores for average daily pain severity, night pain severity, and pain interference with sleep. Duloxetine at 60 and 120 mg per day separated from placebo for average pain and night pain improvement as early as one week after treatment began, whereas sleep interference improvement separated from placebo at the three visits it was assessed (Weeks 4, 8, and 12). Change in sleep interference was moderately to strongly correlated (P<0.001) with changes in average pain (r=0.46) and nighttime pain severity (r=0.53). These results confirm the association between the improvement in daily pain and nighttime pain, and improvement in sleep interference for a large population without depression or somnolence. Although this association cannot establish causality, these results provide some evidence for the possibility that pain may mediate the sleep problem associated with DPNP and perhaps chronic pain in general.

A comparison of initial duloxetine dosing strategies in patients with major depressive disorder.

OBJECTIVE: To compare the effects of starting doses of duloxetine taken with or without food on tolerability and efficacy in patients with major depressive disorder (MDD). METHOD: This double-blind, concurrent-dose-controlled, parallel-design trial contained a variable expected-duration placebo lead-in period and was conducted in adult outpatients with DSM-IV-TR-defined MDD at psychiatric outpatient sites between October 2004 and January 2006. In actuality, patients received placebo for 1 week and then were randomly assigned to duloxetine 30 mg once daily in the morning (q.a.m.) (N = 219), 30 mg twice daily (b.i.d.) (N = 213), or 60 mg q.a.m. (N = 215) for 1 week along with 1 of 2 instructions about food: take study drug with food or do not take within 1 hour of eating. For the remaining 5 weeks of acute treatment, all patients received 60 mg once daily. The primary objective was to compare incidence of treatment-emergent nausea at 30 mg q.a.m. versus 60 mg q.a.m. using item 112 (nausea) of the Association for Methodology and Documentation in Psychiatry adverse event scale (AMDP-5). Secondary outcome measures included mean change on AMDP-5 item 112, discontinuations due to adverse events, mean changes in AMDP-5 items and subscales, spontaneously reported treatment-emergent adverse events, and vital signs. Efficacy was evaluated by the 17-item Hamilton Rating Scale for Depression (HAM-D-17). RESULTS: The primary analysis, which combined data from both food groups, showed no significant difference in the incidence of nausea between starting doses of 30 mg q.a.m. and 60 mg q.a.m. (23% vs. 29%, respectively; p = .207). However, mean changes on the AMDP-5 nausea item revealed a significant main effect of food (p = .010) and a significant interaction between food and starting dose (p = .033). The food-by-dose interaction indicated that the benefit from taking drug with food was greatest in patients started at 60 mg q.a.m., and the benefit of starting at 30 mg q.a.m. was greatest in patients taking drug without food. In patients who took study drug without food, there was a significant difference across initial-dose groups for discontinuation due to adverse events (30 mg q.a.m. = 3.6%, 30 mg b.i.d. = 14.0%, 60 mg q.a.m. = 10.2%; 30 mg q.a.m. vs. 30 mg b.i.d., p = .008; 30 mg q.a.m. vs. 60 mg q.a.m., p = .066); however, in patients who took study drug with food, discontinuations due to adverse events did not significantly differ (30 mg q.a.m. = 5.4%, 30 mg b.i.d. = 7.5%, 60 mg q.a.m. = 7.4%; all p values > .50). Patients who started at 30 mg b.i.d. or 60 mg q.a.m. without food did not differ regarding mean changes (i.e., increases) in the common adverse events score after 1 week of treatment but had significantly greater mean changes than patients who started at 30 mg q.a.m. without food (0.87, 0.82, and 0, respectively; p < .05 vs. 30 mg b.i.d. and 60 mg q.a.m.). No significant differences were found between initial-dose groups in vital signs. CONCLUSIONS: These data imply that starting dulox-etine at 30 mg q.a.m. for 1 week with or without food or starting duloxetine at the therapeutic dose of 60 mg q.a.m. with food can improve the initial tolerability of the medication. Adding this information to existing knowledge of duloxetine will enable the clinician to tailor therapy most appropriately for the individual patient. CLINICAL TRIALS REGISTRATION: ClinicalTrials.gov identifier NCT 00191061.

Treatment approaches to major depressive disorder relapse. Part 1: dose increase.

OBJECTIVE: Although continuing antidepressant treatment after patients have responded to medication has been shown to greatly reduce the risk of relapse, this risk is not eliminated. A number of theories have been proposed to account for this apparent loss of efficacy. A common initial approach to managing relapse is to increase the dose of antidepressant. We prospectively evaluated the likelihood of response to increasing the fluoxetine doses in patients relapsing during a long-term efficacy study of two fluoxetine dosing regimens. METHOD: Patients meeting the DSM-IV criteria for major depressive disorder with modified HAMD17 scores > or =18 and CGI-severity scores > or =4 were treated for 13 weeks with open-label 20 mg/day fluoxetine in a multicenter US study. Responders (n = 501) were randomized to 20 mg fluoxetine daily, placebo, or 90 mg enteric-coated fluoxetine weekly for 25 weeks of double-blind continuation treatment. If the patients relapsed during the continuation phase, they were offered a 25-week optional rescue treatment phase during which the study medication dose was increased as follows: (1) patients on placebo had treatment with fluoxetine 20 mg/day reinitiated, (2) patients on fluoxetine 20 mg/day had their dose increased to 40 mg/day, and (3) patients on a 90-mg weekly dose had their dose increased to 90 mg twice a week. The results of the rescue phase for the latter two groups who relapsed while on continuation treatment with fluoxetine are reported. Response was defined as a 50% reduction in the modified HAMD17 score since time of relapse and a CGI-severity score < or =2. Additional efficacy analyses included HAMD and CGI-severity changes from baseline to endpoint. Safety measures included assessment of treatment-emergent adverse events, vital signs, and laboratory measures. RESULTS: Overall, patients relapsing during the continuation treatment responded to an increased dose (57% of the 40-mg-daily group and 72% of the enteric-coated 90-mg-twice-weekly group). Mean modified HAMD17 scores decreased from a mean of approximately 20 to below 8 and were maintained for up to 6 months in the responders. Thirty-five percent of patients either did not respond or initially responded but again relapsed after augmentation of medication. CONCLUSIONS: The patients relapsing after initially responding to fluoxetine can benefit from an increase in fluoxetine dose. These results also generally support increasing dose as a first-line treatment strategy for a patient who has relapsed while taking a previously effective dose of an antidepressant. Increasing enteric-coated fluoxetine 90 mg once weekly to twice weekly appeared to be as well-tolerated and effective in restoring response as increasing a daily fluoxetine dose from 20 to 40 mg.

Treatment approaches to major depressive disorder relapse. Part 2: reinitiation of antidepressant treatment.

BACKGROUND: Anecdotal reports concerning mood disorder patients suggest restarting drug treatment in patients who prematurely discontinue it may be associated with a diminished chance of response upon rechallenge. We evaluated the likelihood of response to reinitiation of fluoxetine treatment in patients relapsing after switching to placebo during a long-term efficacy study of two different dosing regimens of fluoxetine. METHOD: Patients who met the DSM-IV major depressive disorder criteria with modified HAMD17 scores > or =18 and CGI-Severity scores > or =4 were treated with open-label 20 mg/day fluoxetine for 13 weeks in a multicenter US study. Responders (n = 501) were randomized to placebo, 20 mg fluoxetine daily, or 90 mg enteric-coated fluoxetine weekly for 25 weeks of double-blind continuation treatment. Patients relapsing during the continuation phase were offered 25 weeks of double-blind rescue treatment during which the study medication dose was increased as follows: (1) patients on placebo had treatment with fluoxetine 20 mg/ day reinitiated; (2) patients on fluoxetine 20 mg/day had their dose increased to 40 mg/day, and (3) patients on a 90-mg weekly dose had their dose increased to 90 mg twice a week. Only the results of the rescue phase for the group who relapsed while on continuation treatment with placebo are reported here. Analyses included percentage of responders (50% reduction of modified HAMD17 and CGI-Severity < or =2) and assessments of change from baseline to endpoint (HAMD, CGI-Severity). Safety measures included assessment of vital signs, laboratory measures, and treatment-emergent adverse events. RESULTS: Of 122 patients assigned to placebo, 57 (47%) relapsed during continuation treatment. Fifty-five (96%) of these elected to enter double-blind rescue treatment. Overall, patients who relapsed upon switching to placebo responded well to reinitiation of fluoxetine (62%). The mean modified HAMD17 score decreased from 20 to less than 9 and was maintained for up to 6 months. Thirty-eight percent of patients either did not respond or initially responded but again relapsed after reinitiation of medication. CONCLUSION: This study suggests that patients who, after an initial response to fluoxetine, relapse upon switching to placebo have a relatively high probability of responding to the reinitiation of fluoxetine treatment. These results challenge the view that the efficacy of an agent prematurely discontinued is diminished when such an agent is restarted. They also generally support reinitiation of the same antidepressant as a 'first-line' treatment strategy in patients who relapsed after stopping a previously effective antidepressant.

Acute efficacy of fluoxetine versus sertraline and paroxetine in major depressive disorder including effects of baseline insomnia.

This study assessed whether fluoxetine, sertraline, and paroxetine differ in efficacy and tolerability in depressed patients and the impact of baseline insomnia on outcomes. Patients (N = 284) with DSM-IV major depressive disorder were randomly assigned in a double-blind fashion to fluoxetine, paroxetine, or sertraline for 10 to 16 weeks of treatment. Using the Hamilton Rating Scale for Depression (HAM-D) sleep disturbance factor score, patients were categorized into low (<4) or high (>or=4) baseline insomnia subgroups. Changes in depression and insomnia were assessed. Safety assessments included treatment-emergent adverse events (AEs), reasons for discontinuation, and AEs leading to discontinuation. In addition, AEs were evaluated within insomnia subgroups to determine emergence of activation or sedation. Depression improvement, assessed with the HAM-D-17 total score, was similar among treatments in all patients (p = 0.365) and the high (p = 0.853) and low insomnia (p = 0.415) subgroups. Insomnia improvement, assessed with the HAM-D sleep disturbance factor score, was similar among treatments in all patients (p = 0.868) and in the high (p = 0.852) and low insomnia (p = 0.982) subgroups. Analyses revealed no significant differences between treatments in the percentages of patients with substantial worsening, any worsening, worsening at endpoint, or improvement at endpoint in the HAM-D sleep disturbance factor in either insomnia subgroup. Treatments were well tolerated in most patients. No significant differences between treatments in the incidence of AEs suggestive of activation or sedation were seen in the insomnia subgroups. These data show no significant differences in acute treatment efficacy and tolerability across fluoxetine, sertraline, and paroxetine in major depressive disorder patients. Improvement in overall depression and in associated insomnia was achieved by most patients regardless of baseline insomnia.

Once-daily atomoxetine treatment for children with attention-deficit/hyperactivity disorder, including an assessment of evening and morning behavior: a double-blind, placebo-controlled trial.

OBJECTIVES: Atomoxetine seems to be as effective for treating attention-deficit/hyperactivity disorder (ADHD) when the daily dose is administered once in the morning as when the dose is divided and administered in the morning and evening. In the present study, the efficacy of atomoxetine administered once daily among children with ADHD was assessed throughout the day, including the evening and early morning. Another goal was to determine how early in treatment it was possible to discern a specific effect of the drug on ADHD symptoms. METHODS: This study was a randomized, multicenter, double-blind, placebo-controlled trial conducted at 12 outpatient sites in the United States. A total of 197 children, 6 to 12 years of age, who had been diagnosed as having ADHD, on the basis of the Diagnostic and Statistical Manual of Mental Disorders (4th ed.) criteria, were randomized to receive 8 weeks of treatment with atomoxetine or placebo, dosed once daily in the mornings. ADHD symptoms were assessed with parent and investigator rating scales. The primary outcome measure was the Attention-Deficit/Hyperactivity Disorder Rating Scale-IV-Parent Version: Investigator-Administered and Scored total score. Daily parent assessments of children's home behaviors in the evening and early morning were recorded with an electronic data entry system. This instrument measures 11 specific morning or evening activities, including getting up and out of bed, doing or completing homework, and sitting through dinner. RESULTS: Seventy-one percent of the children enrolled were male, 69% met criteria for the combined subtype (both inattentive and hyperactive/impulsive symptoms), and the most common psychiatric comorbidity was oppositional defiant disorder (35%). Once-daily atomoxetine (final mean daily dose of 1.3 mg/kg) was significantly more effective than placebo in treating core symptoms of ADHD. Mean reductions in the Attention-Deficit/Hyperactivity Disorder Rating Scale-IV-Parent Version: Investigator-Administered and Scored total score were significantly greater for patients randomized to atomoxetine, beginning at the first visit after the initiation of treatment and continuing at all subsequent visits. Both inattentive and hyperactive/impulsive symptom clusters were significantly reduced with atomoxetine, compared with placebo. With continued treatment and dose titrations, core symptoms of ADHD continued to decrease throughout the 8-week study. Mean reductions in the daily parent assessment total scores for patients randomized to atomoxetine were superior during the first week, beginning with the first day of dosing, and were also superior at endpoint. Efficacy outcomes for the evening hours for atomoxetine-treated patients were superior to those for placebo-treated patients, as assessed with 2 different assessment scales. Decreases in the daily parent assessment morning subscores at endpoint showed a significant reduction in symptoms that lasted into the mornings. Rates of discontinuations attributable to adverse events were <5% for both groups. Adverse events reported significantly more frequently with atomoxetine were decreased appetite, somnolence, and fatigue. CONCLUSIONS: Among children 6 to 12 of age who had been diagnosed as having ADHD, once-daily administration of atomoxetine in the morning provided safe, rapid, continuous, symptom relief that lasted not only into the evening hours but also into the morning hours. Atomoxetine treatment was safe and well tolerated.