Low doses of controlled-release paroxetine in the treatment of late-life depression: a randomized, placebo-controlled trial.

OBJECTIVE: To evaluate the efficacy and tolerability of low daily doses of controlled-release (CR) paroxetine in patients with late-life depression. METHOD: This was a 10-week, multicenter, placebo-controlled, double-blind, fixed-dose trial randomly assigning patients >or= 60 years old to daily doses of paroxetine CR 12.5 mg (N = 168), paroxetine CR 25 mg (N = 177), or placebo (N = 180). Patients had major depressive disorder (DSM-IV criteria) and 17-item Hamilton Rating Scale for Depression (HAM-D) total scores of >or= 18. The primary efficacy variable was the change from baseline to study endpoint in total HAM-D scores. The study was conducted from June 2003 to October 2004. RESULTS: The drug/placebo difference in HAM-D change from baseline at study endpoint was -1.8 (95% CI = -3.41 to -0.19, p = .029) for paroxetine CR 12.5 mg, and -3.3 (95% CI = -4.84 to -1.68, p < .001) for paroxetine CR 25 mg. A significantly larger percentage of patients achieved remission (HAM-D total score or= 60 years of age, although effect sizes are relatively smaller with the 12.5 mg/day dose.

Multiple dose pharmacokinetics of paroxetine in children and adolescents with major depressive disorder or obsessive-compulsive disorder.

The current study examined the pharmacokinetics (PK), safety, and tolerability of paroxetine after repeated multiple oral dosing in children and adolescents with major depressive or obsessive-compulsive disorder. In this 6-week, open-label, repeat dose, dose-rising study, 62 patients (27 children and 35 adolescents) were treated with paroxetine 10 mg/day for the first 2 weeks of the study, 20 mg/day for the next 2 weeks, and 30 mg/day for the final 2 weeks. Pharmacokinetic sampling and safety assessments occurred at baseline and subsequently on the final treatment day of each dosing level. Between-patient variability in PK was pronounced at the 10 mg dose level, but markedly reduced at higher doses. A supra-proportional increase in plasma concentrations with increasing dose was evident in both age groups. Data for C(max) and AUC(0-24) indicated that, at each dose level, paroxetine steady-state systemic exposure was higher in children than in adolescents. The differences between age groups, however, diminished with each increasing dose, and were virtually abolished when differences in weight among different age groups were considered. Stepwise regression analysis indicated that both oral clearance and volume of distribution were highly dependent on paroxetine dose, cytochrome P4502D6 genotype, and weight (p<0.0001), but not age or sex. Paroxetine was generally safe and well tolerated in both age groups, with the most frequently observed adverse events being largely consistent with those observed in prior paroxetine studies of adult psychiatric patients. Certain gastrointestinal and behavioral activation events (aggressive reaction and nervousness) were reported more frequently in the youngest age group.