Biomedical subjects

Craig Mallinckrodt

Publications and source records attributed to Craig Mallinckrodt.

10 recordsLinked to original sources

PubMed2006

A local influence sensitivity analysis for incomplete longitudinal depression data.

In the analyses of incomplete longitudinal clinical trial data, there has been a shift, away from simple ad hoc methods that are valid only if the data are missing completely at random (MCAR), to more principled (likelihood-based or Bayesian) ignorable analyses, which are valid under the less restrictive missing at random (MAR) assumption. The availability of the necessary standard statistical software allows for such analyses in practice. Although the possibility of data missing not at random (MNAR) cannot be ruled out, it is argued that analyses valid under MNAR are not well suited for the primary analysis in clinical trials. Therefore, rather than either forgetting about or blindly shifting to an MNAR framework, the optimal place for MNAR analyses is within a sensitivity analysis context. Such analyses can be used, for example, to assess how sensitive results from an ignorable analysis are to possible departures from MAR and how much results are affected by influential observations. In this article, we apply the local influence sensitivity tool (Verbeke et al., 2001) to a longitudinal depression trial, thereby applying it to continuous outcomes from clinical trials.

Antidepressive Agents↗

PubMed2005

Time course of depression-symptom improvement during treatment with duloxetine.

The aim of this study was to examine the longitudinal response for overall and individual symptoms during the treatment of major depressive disorder. Data were pooled from two 9-week trials, which compared duloxetine 60-mg QD (n=251) with placebo (n=261) in the treatment of MDD. Changes from baseline in the 17-item Hamilton Depression Rating Scale (HAMD17) and in the Visual Analog Scales for pain were analyzed. Compared to placebo-treated patients, duloxetine-treated patients experienced greater improvement (P<.05) in the HAMD17 total score at Week 2. The individual symptoms showing the most rapid improvements (Week 1) were depressed mood, guilt, suicidal ideation, work/activities, and psychic anxiety as well as VAS back pain and shoulder pain. At subsequent visits, significant improvements were observed in retardation (Week 2); hypochondriasis (Week 3); general somatic symptoms (Week 5); middle and late insomnia (Week 7); and gastrointestinal (GI) symptoms, genital symptoms (level of sexual interest or ease of sexual arousal), insight, and early insomnia (Week 9). Significant advantages for duloxetine were not achieved at any visit for agitation, somatic anxiety, or weight loss. At Weeks 1 and 2, placebo-treated patients had significantly lower GI symptoms and reported less weight loss compared with duloxetine-treated patients; however, differences were not significant at subsequent visits. Furthermore, duloxetine was superior to placebo on GI symptoms at endpoint compared to placebo-treated patients; duloxetine-treated patients had a significantly higher response rate at Week 2 and a higher remission rate at Week 5. These results may help clinicians establish more accurate expectations regarding treatment with duloxetine.

Adult↗

PubMed2005

Cardiovascular profile of duloxetine, a dual reuptake inhibitor of serotonin and norepinephrine.

This analysis assessed the effects of duloxetine, a dual reuptake inhibitor of serotonin and norepinephrine, on indices of cardiovascular safety, including heart rate, blood pressure (BP), and electrocardiograms (ECGs), in a large group of clinical trial patients with depression. Data were available from 8 double-blind, randomized, placebo-controlled (n = 777), and active comparator-controlled depression trials. Duloxetine (n = 1139) doses ranged from 40 to 120 mg/d, and fluoxetine (n = 70) and paroxetine (n = 359) were administered at a dose of 20 mg/d. Patients were treated for 8 to 9 weeks. There was a significant increase for duloxetine compared with placebo for heart rate (1.6 vs. -0.6 beats per minute) and for systolic BP (1.0 vs. -1.2 mm Hg); the difference for diastolic BP (1.1 vs. 0.3) was not significant. There were no significant differences between duloxetine and placebo treatment groups in the incidence of sustained (at least 3 consecutive visits) elevations in systolic (duloxetine 1.0%, placebo 0.4%), diastolic (duloxetine 0.4%, placebo 0.4%), or either (duloxetine 1.3%, placebo 0.8%) BP. Moreover, the effect of duloxetine on mean changes in supine systolic and diastolic BP was not significantly different from that of fluoxetine or paroxetine. Drug-placebo differences in mean changes in electrocardiograms (eg, QTc, PR, and QRS intervals) were neither statistically nor clinically significant, with the exception that duloxetine 120 mg/d had significant decreases in PR and QRS intervals compared with placebo. These data demonstrate that duloxetine has modest effects on heart rate and BP and no clinically meaningful effect on electrocardiogram profiles in a relatively healthy cohort of clinical trial patients. The cardiovascular effects of duloxetine appear to be comparable with medications considered to be first-line options for depression.

Adult↗

PubMed2004

Analyzing incomplete longitudinal clinical trial data.

Using standard missing data taxonomy, due to Rubin and co-workers, and simple algebraic derivations, it is argued that some simple but commonly used methods to handle incomplete longitudinal clinical trial data, such as complete case analyses and methods based on last observation carried forward, require restrictive assumptions and stand on a weaker theoretical foundation than likelihood-based methods developed under the missing at random (MAR) framework. Given the availability of flexible software for analyzing longitudinal sequences of unequal length, implementation of likelihood-based MAR analyses is not limited by computational considerations. While such analyses are valid under the comparatively weak assumption of MAR, the possibility of data missing not at random (MNAR) is difficult to rule out. It is argued, however, that MNAR analyses are, themselves, surrounded with problems and therefore, rather than ignoring MNAR analyses altogether or blindly shifting to them, their optimal place is within sensitivity analysis. The concepts developed here are illustrated using data from three clinical trials, where it is shown that the analysis method may have an impact on the conclusions of the study.

Antidepressive Agents↗

PubMed2004

Duloxetine in the treatment of depression: a double-blind placebo-controlled comparison with paroxetine.

CONTEXT: Major depressive disorder causes significant morbidity and mortality. Current therapies fail to fully treat both emotional and physical symptoms of major depressive disorder. OBJECTIVE: To evaluate duloxetine, a dual reuptake inhibitor of serotonin and norepinephrine, on improvement of emotional and painful physical symptoms. DESIGN: Randomized, double-blind, evaluation of duloxetine at 40 mg/d (20 mg twice daily) and 80 mg/d (40 mg twice daily) versus placebo and paroxetine 20 mg/d in depressed outpatients. MAIN OUTCOME MEASURES: The primary efficacy measure was the 17-item Hamilton Depression Rating Scale. Visual Analog Scales for pain, Clinical Global Impression of Severity, Patient's Global Impression of Improvement, and Quality of Life in Depression Scale were also used. Safety was evaluated by assessing discontinuation rates, adverse event rates, vital signs, and laboratory tests. RESULTS: Duloxetine 80 mg/d was superior to placebo on mean 17-item Hamilton Depression Rating Scale total change by 3.62 points (95% CI 1.38, 5.86; P = 0.002). Duloxetine at 40 mg/d was also significantly superior to placebo by 2.43 points (95% CI 0.19, 4.66; P = 0.034), while paroxetine was not (1.51 points; 95% CI -0.55, 3.56; P = 0.150). Duloxetine 80 mg/d was superior to placebo for most other measures, including overall pain severity, and was superior to paroxetine on 17-item Hamilton Depression Rating Scale improvement (by 2.39 points; 95% CI 0.14, 4.65; P = 0.037) and estimated probability of remission (57% for duloxetine 80 mg/d, 34% for paroxetine; P = 0.022). The only adverse event reported significantly more frequently for duloxetine 80 mg/d than for paroxetine was insomnia (19.8% for duloxetine 80 mg/d, 8.0% for paroxetine; P = 0.031). Hypertension incidence was not affected by any treatment. CONCLUSION: Duloxetine therapy was efficacious for emotional and physical symptoms of depression, with a selective serotonin reuptake inhibitor-like profile of side effects.

Adult↗

PubMed2003

Duloxetine in treatment of anxiety symptoms associated with depression.

Most patients with major depressive disorder (MDD) have symptoms of anxiety associated with their depression. Duloxetine, a potent and balanced dual serotonin and norepinephrine reuptake inhibitor, is effective in the treatmentof depression. We investigated its effects in treating the symptoms of anxiety in depressed patients. This investigation includes all the placebo-controlled studies of duloxetine in MDD but focuses on four trials in which duloxetine was superior to placebo on the primary outcome measure of the 17-item Hamilton Depression Rating Scale (HAMD(17)) total score. Studies 1 and 2 included duloxetine at 60 mg/d (the recommended starting and therapeutic dose) and placebo. Study 3 included duloxetine 120 mg/d (administered as 60 mg b.i.d.), fluoxetine 20 mg/d, and placebo. Study 4 included duloxetine 40 mg/d (administered as 20 mg b.i.d.), duloxetine 80 mg/d (administered as 40 mg b.i.d.), paroxetine 20 mg/d, and placebo. Anxiety was assessed in all studies using the HAMD anxiety/somatization subfactor and the anxiety-psychic item (HAMD Item 10). Studies 3 and 4 also included the Hamilton Anxiety Rating Scale (HAMA). Across the four studies, duloxetine at doses of >/=60 mg was compared with placebo on 10 outcomes and with either paroxetine or fluoxetine on 6 outcomes. In 8 comparisons, mean improvement for duloxetine was significantly greater than placebo at the last study visit and/or across all study visits. In 3 comparisons, the mean improvement for duloxetine was significantly greater than paroxetine or fluoxetine. In these studies, duloxetine provided rapid relief of anxiety symptoms associated with depression. Previous reports have summarized duloxetine's efficacy in treating the core emotional symptoms and painful physical symptoms associated with depression. Duloxetine's efficacy in treating a broad spectrum of symptoms associated with depression, including mood, anxiety, and painful physical symptoms, may be attributed to dual reuptake inhibition of both serotonin and norepinephrine. Efficacy in these three key symptom domains may in turn explain the high probabilities of remission (43-57%) observed in these studies.

Adult↗

PubMed2003

Placebo response and antidepressant clinical trial outcome.

Placebo response magnitude is suspected to affect the outcome of antidepressant clinical trials. To evaluate this, 52 randomized, double-blind, placebo-controlled clinical trials obtained from the FDA were examined to correlate placebo response magnitude with trial outcome. The magnitude of symptom reduction, percentage mean change from baseline in the Hamilton Depression Rating Scale (HAM-D), was assessed for patients assigned to placebo or an antidepressant. Correlation coefficients between symptom reduction with placebo and antidepressants and between symptom reduction with placebo and magnitude of advantage of antidepressants over placebo were assessed. A statistically significant positive correlation was seen between placebo and antidepressant response magnitude (r =.40, p <.001) and between placebo response magnitude and the advantage of antidepressants over placebo (r = -.592, p <.0001). Only 21.1% of antidepressant treatment arms in trials with high placebo response (>30% mean change from baseline) showed statistical superiority over placebo compared with 74.2% in trials with a low placebo response (< or =30). Response magnitude varies and has an important effect on antidepressant clinical trials, illustrating the need for a placebo arm to determine if the trial was sensitive to treatment differences and highlighting the dangers of cross-study comparisons.

Antidepressive Agents↗

PubMed2002

Duloxetine in the treatment of major depressive disorder: a double-blind clinical trial.

BACKGROUND: Duloxetine hydrochloride, a dual reuptake inhibitor of serotonin and norepinephrine, was evaluated for therapeutic efficacy and safety/tolerability in the treatment of major depression. METHOD: In an 8-week multicenter, double-blind, placebo-controlled study, 173 patients (aged 18-65 years) with DSM-IV major depressive disorder were randomly allocated to receive placebo (N = 70), duloxetine (N = 70), or fluoxetine, 20 mg q.d. (N = 33). Duloxetine dose was titrated in the first 3 weeks in a forced-titration regimen from 40 mg (20 mg b.i.d.) to 120 mg/day (60 mg b.i.d.). Patients were required to have a Clinical Global Impressions (CGI)-Severity of Illness scale score of at least moderate severity (> or = 4) and a 17-item Hamilton Rating Scale for Depression (HAM-D-17) total score of at least 15. Patients could not have had any current primary DSM-IV Axis I diagnosis other than major depressive disorder, or any anxiety disorder as a primary diagnosis within the past year, excluding specific phobias. The primary efficacy measurement was the HAM-D-17 total score, and secondary measures included the Montgomery-Asberg Depression Rating Scale, CGI-Severity of Illness and CGI-Improvement, and Patient Global Impression of Improvement. Safety was evaluated by recording the occurrence of discontinuation rates and treatment-emergent adverse events and by measurement of vital signs and laboratory analytes. RESULTS: Duloxetine was superior to placebo in change on the HAM-D-17 (p = .009). Estimated probabilities of response and remission were 64% and 56%, respectively, for duloxetine, compared with 52% and 30% for fluoxetine and 48% and 32% for placebo. Duloxetine was numerically superior to fluoxetine on the primary and most of the secondary outcome measures. In general, duloxetine was well tolerated; 76% of patients achieved the maximum dose, and insomnia and asthenia were the only adverse events reported statistically significantly (p < .05) more frequently by duloxetine-treated patients compared with placebo-treated patients. CONCLUSION: These data indicate that duloxetine is efficacious for the treatment of major depressive disorder and is well tolerated and safe.

Adrenergic Uptake Inhibitors↗

PubMed2002

Effect of perioperative oral carprofen on postoperative pain in dogs undergoing surgery for stabilization of ruptured cranial cruciate ligaments.

A randomized, placebo-controlled, parallel study was conducted to investigate the effectiveness of oral carprofen for the control of postoperative pain in dogs undergoing knee surgery for stabilization of ruptured cranial cruciate ligaments. Dogs were randomly assigned to treatment with carprofen (n = 10) or placebo (n = 9). Pain was assessed at 1, 2, 4, 6, 24, and 48 hours and 10 and 21 days postoperatively. Eight of 10 dogs treated with carprofen and five of nine dogs treated with placebo were given at least one dose of morphine as rescue therapy. The mean relative dose of morphine given at 1 hour (P =.01) and 24 hours (P =.02) after surgery was greater for dogs treated with carprofen than for dogs given a placebo. There were no significant postoperative differences in cortisol levels or any measured variable. It appears that the scoring system used was not sensitive enough to detect differences in pain between a known analgesic and a placebo.

Administration, Oral↗

PubMed2002

Duloxetine for the treatment of major depressive disorder.

>55% were observed in two of the studies, while in a third study the probability of remission with duloxetine treatment was nearly three times that observed with placebo (44% versus 16%). Duloxetine also produced significant improvement in painful physical symptoms compared with placebo, in many cases after only 2 weeks of treatment. The discontinuation rate due to adverse events (14.6%) was similar to those observed with selective serotonin reuptake inhibitors. The most frequently reported adverse events were nausea, dry mouth, fatigue, and insomnia. Conclusion. Duloxetine was demonstrated to be safe and effective in the treatment of MDD. The starting dose with the best balance of efficacy and tolerability is 60 mg QD.

Antidepressive Agents↗