A double-blind efficacy and safety study of duloxetine flexible dosing in children and adolescents with major depressive disorder

A randomized, placebo-controlled study of duloxetine for the treatment of children and adolescents with generalized anxiety disorder

OBJECTIVE

To evaluate the efficacy, safety, and tolerability of the selective serotonin norepinephrine inhibitor duloxetine in children and adolescents with generalized anxiety disorder (GAD).

METHOD

Youth aged 7 through 17 years with a primary diagnosis of GAD were treated with flexibly dosed duloxetine (30-120 mg daily, n = 135) or placebo (n = 137) for 10 weeks, followed by open-label duloxetine (30-120mg daily) for 18 weeks. Efficacy measures included the Pediatric Anxiety Rating Scale (PARS), Clinical Global Impression-Severity (CGI-Severity) scale, and Children's Global Assessment Scale (CGAS). Safety measures included the Columbia-Suicide Severity Rating Scale (C-SSRS) as well as vital signs and electrocardiographic and laboratory monitoring.

RESULTS

On the primary efficacy measure (PARS severity for GAD), mean improvement from baseline to 10 weeks was statistically significantly greater for duloxetine (-9.7) compared with placebo (-7.1, p ≤ .001, Cohen's d: 0.5). Symptomatic response (50% improvement on the PARS severity for GAD), remission (PARS severity for GAD ≤8), and functional remission (CGAS >70) rates for the duloxetine group (59%, 50%, 37%, respectively) were statistically significantly greater than for the placebo group (42%, 34%, 24%, respectively, p ≤ .05) during acute treatment. Changes in systolic and diastolic blood pressure and discontinuation because of adverse events did not statistically differ between the duloxetine and placebo groups, although gastrointestinal-related adverse events, oropharyngeal pain, dizziness, cough, and palpitations were reported with a statistically significantly greater incidence for the duloxetine group compared with the placebo group. Mean changes in pulse and weight for the duloxetine group (+6.5 beats/min, -0.1 kg, respectively) were statistically different from the placebo group (+2.0 beats/min, +1.1 kg, respectively, p ≤ .01).

CONCLUSION

In this study, duloxetine was superior to placebo on the primary efficacy analysis of mean change from baseline to week 10 on the PARS severity for GAD score, and safety results were consistent with the known safety profile of duloxetine in pediatric and adult patients. Clinical trial registration information-A Study in Pediatric Participants With Generalized Anxiety Disorder; http://clinicaltrials.gov; NCT01226511.

Pharmacokinetics of orally administered duloxetine in children and adolescents with major depressive disorder

BACKGROUND

Duloxetine, a selective serotonin (5-hydroxytryptamine) and norepinephrine reuptake inhibitor, has been approved since 2004 for the treatment of adults with major depressive disorder (MDD). It is currently not approved for use in pediatric patients (aged <18 years) with MDD. The clinical development program for duloxetine in the pediatric MDD population, which consisted of three clinical studies, provided extensive data on the safety, tolerability, and pharmacokinetics of duloxetine across a wide dose range in pediatric patients of differing ages, sex, body weights, and sexual maturation.

OBJECTIVES

The objectives were to characterize the pharmacokinetics of duloxetine based on population modeling following daily oral administration in children and adolescents aged 7-17 years diagnosed with MDD; to estimate the magnitude of between- and within-patient variability; to identify potential patient factors affecting duloxetine pharmacokinetics, and to compare duloxetine pharmacokinetics in the pediatric population with those characterized in adults.

METHODS

The analyses meta-dataset was created from pharmacokinetic and demographic data available from one phase II (open-label) and two phase III (randomized, double-blind) clinical trials of duloxetine in children and adolescents. Patients received 20-120 mg of oral duloxetine once daily. Duloxetine concentrations (a total of 1,581 concentrations) were obtained from 428 patients: 34% were children (aged 7-11 years) and 66% were adolescents (aged 12-18 years). Population modeling analyses were performed using nonlinear mixed-effects modeling and the first-order conditional estimation method with interaction. Patient factors were assessed for their potential influence on duloxetine apparent clearance (CL/F) and apparent volume of distribution (V d/F). Duloxetine pharmacokinetic parameters and model-predicted duloxetine concentrations at steady state in the pediatric population were compared with those in adults.

RESULTS

Duloxetine pharmacokinetics in pediatric patients was described by a one-compartmental model. Typical values of CL/F, V d/F, and half-life (t 1/2) at 60 mg/day of duloxetine were 79.7 L/h, 1,200 L, and 10.4 h, respectively. The between-patient variability in CL/F and V d/F was 68 and 87%, respectively, while within-patient variability was 57% (proportional error) and 2.04 ng/mL (additive error). Body surface area (BSA), dose, and race had a statistically significant effect on duloxetine pharmacokinetics. With a 2.2-fold increase in BSA, the CL/F increased about twofold. A sixfold increase in dose (20 to 120 mg) decreased CL/F by 32%. In American Indian patients, V d/F was 131% higher than the other races combined. Age, sex, body mass index, serum creatinine, cytochrome P450 2D6 predicted phenotype, and menarche status did not have a statistically significant effect. Estimates of CL/F and V d/F were higher in the pediatric population than in adults; subsequently, the average steady-state duloxetine concentration was approximately 30% lower in the pediatric population than in adults.

CONCLUSIONS

Duloxetine pharmacokinetics was similar in children and adolescents with MDD. The statistically significant effects of dose, BSA, and race on duloxetine pharmacokinetics in pediatric patients did not appear to be clinically meaningful. At a given dose, the typical steady-state duloxetine concentrations in the pediatric population were lower than in adults, and the distribution of steady-state duloxetine concentrations in pediatric patients were typically in the lower range of concentrations in adults.

A double-blind efficacy and safety study of duloxetine fixed doses in children and adolescents with major depressive disorder

OBJECTIVE

The purpose of this study was to evaluate the efficacy and safety of duloxetine fixed dose in the treatment of children (7-11 years) and adolescents (12-17 years) with major depressive disorder (MDD).

METHODS

Patients (n=463) in this 36 week study (10 week acute and 26 week extension treatment) received duloxetine 60 mg QD (n=108), duloxetine 30 mg QD (n=116), fluoxetine 20 mg QD (n=117, active control), or placebo (n=122). Measures included: Children's Depression Rating Scale-Revised (CDRS-R), treatment-emergent adverse events (TEAEs), and Columbia-Suicide Severity Rating Scale (C-SSRS).

RESULTS

Neither active drug (duloxetine or fluoxetine) separated significantly (p<0.05) from placebo on mean change from baseline to end-point (10 weeks) on the CDRS-R total score. Total TEAEs and discontinuation for AEs were significantly (p<0.05) higher only for the duloxetine 60 mg group versus the placebo group during acute treatment. No clinically significant electrocardiogram (ECG) or laboratory abnormalities were observed, and no completed suicides or deaths occurred during the study. A total of 7 (6.7%) duloxetine 60 mg, 6 (5.2%) duloxetine 30 mg, 9 (8.0%) fluoxetine, and 11 (9.4%) placebo patients had worsening of suicidal ideation from baseline during acute treatment. Of the patients with suicidal ideation at baseline, 13/16 (81%) duloxetine 60 mg, 16/17 (94%) duloxetine 30 mg, 11/16 (69%) fluoxetine, and 13/15 (87%) placebo had improvement in suicidal ideation at end-point during acute treatment. One fluoxetine, one placebo, and six duloxetine patients had treatment-emergent suicidal behavior during the 36 week study.

CONCLUSIONS

Trial results were inconclusive, as neither the investigational drug (duloxetine) nor the active control (fluoxetine) separated from placebo on the CDRS-R at 10 weeks. No new duloxetine safety signals were identified relative to those seen in adults. Clinical Trial Registry Number ( www.ClinicalTrials.gov ): NCT00849693.