Efficacy and tolerability of paroxetine for the long-term treatment of generalized anxiety disorder.
BACKGROUND
Paroxetine has demonstrated efficacy in depression and anxiety disorders, including generalized anxiety disorder (GAD). This 32-week study evaluated the maintained efficacy and safety of paroxetine in GAD by assessing the potential for relapse after discontinuation of medication.


METHODS
Adults (N = 652) with DSM-IV GAD and a Clinical Global Impressions-Severity of Illness (CGI-S) score > or = 4 received paroxetine (20-50 mg/day) for 8 weeks. Patients whose CGI-S score had decreased by at least 2 points to < or = 3 at week 8 were randomly assigned to double-blind treatment with paroxetine (N = 278) or placebo (N = 288) for a further 24 weeks. The primary efficacy parameter was the proportion of patients relapsing (an increase in CGI-S score of at least 2 points to a score < or = 4 or withdrawal resulting from lack of efficacy) during double-blind treatment.


RESULTS
Significantly fewer paroxetine than placebo patients relapsed during the 24-week double-blind phase (10.9% vs. 39.9%; p <.001). Placebo patients were almost 5 times more likely to relapse than paroxetine patients (estimated hazard ratio = 0.213 [95% CI = 0.1 to 0.3]; p <.001). Statistical significance in favor of paroxetine was demonstrated for all secondary efficacy parameters, including functional status. Twice as many paroxetine patients as placebo patients (73%) achieved remission. Paroxetine was well tolerated, with no unexpected adverse events reported.


CONCLUSIONS
Paroxetine was found to be effective and well tolerated for both the short- and long-term treatment of DSM-IV GAD. Continued treatment with paroxetine significantly reduced the potential for relapse of GAD symptoms.
Stocchi
Fabrizio
F
Institute of Neurology, Istituto Ricerca Carattere Scientifico Neuromed, Pozzill Italy. fabstocc@tin.it
Nordera
Giampetro
G
Jokinen
Riitta H
RH
Lepola
Ulla M
UM
Hewett
Karen
K
Bryson
Heather
H
Iyengar
Malini K
MK
D000293:Adolescent; D000328:Adult; D000368:Aged; D001008:Anxiety Disorders / Q000175:diagnosis / Q000188:drug therapy*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017374:Paroxetine / Q000009:adverse effects / Q000627:therapeutic use*; D010919:Placebos; D011569:Psychiatric Status Rating Scales; D055502:Secondary Prevention; D017367:Selective Serotonin Reuptake Inhibitors / Q000009:adverse effects / Q000627:therapeutic use*; D012720:Severity of Illness Index; D016037:Single-Blind Method; D013375:Substance Withdrawal Syndrome / Q000517:prevention & control; D016896:Treatment Outcome
D017374:Paroxetine; D010919:Placebos; D017367:Selective Serotonin Reuptake Inhibitors