A double-blind, placebo-controlled, parallel-group, flexible-dose study of venlafaxine extended release capsules in adult outpatients with panic disorder.
OBJECTIVE
To evaluate the efficacy, safety, and tolerability of venlafaxine extended release (ER) in short-term treatment of panic disorder.


METHODS
In this multicenter, double-blind study, conducted from April 2001 to December 2002, 343 adult outpatients who met criteria for panic disorder (with and without agoraphobia) according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, were randomly assigned to flexible-dose venlafaxine ER (75-225 mg/d) or placebo for 10 weeks (N = 155 per group, intent-to-treat population). The primary outcome measure was the percentage of panic-free patients as assessed using the Sheehan Panic and Anticipatory Anxiety Scale. Key secondary measures included the Panic Disorder Severity Scale (PDSS) score and Clinical Global Impressions-Improvement (CGI-I) scale response (score = 1 or 2). Last-observation-carried-forward data were analyzed, and statistical significance was set at p <or= .05.


RESULTS
At week 10, the percentage of patients who were free from full-symptom panic attacks was 52% in the venlafaxine ER group and 43% in the placebo group (p = .11). Mean change from baseline in PDSS total score was significantly (p = .006) greater for the venlafaxine ER group (-9.3) than for the placebo group (-7.5), and significantly (p = .03) more venlafaxine ER-treated patients achieved CGI-I response (71%) than did those receiving placebo (59%) at week 10. Treatment with venlafaxine ER was generally safe and well tolerated. Adverse events were the primary or secondary cause for discontinuation for 7 placebo patients (4%) and 12 venlafaxine ER patients (7%).


CONCLUSIONS
Venlafaxine ER appears to be effective, safe, and well tolerated in short-term treatment of panic disorder, although the results fell just short of significance on the primary outcome measure.


BACKGROUND
clinicaltrials.gov Identifier: NCT00038896.
Liebowitz
Michael R
MR
Department of Psychiatry, Columbia University, New York, NY 10025, USA. mrl1945@aol.com
Asnis
Gregory
G
Mangano
Richard
R
Tzanis
Evan
E
D000553:Ambulatory Care; D003511:Cyclohexanols / Q000627:therapeutic use*; D003692:Delayed-Action Preparations / Q000627:therapeutic use*; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D006801:Humans; D016584:Panic Disorder / Q000175:diagnosis / Q000188:drug therapy* / Q000523:psychology; D017367:Selective Serotonin Reuptake Inhibitors / Q000627:therapeutic use*; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D000069470:Venlafaxine Hydrochloride
D003511:Cyclohexanols; D003692:Delayed-Action Preparations; D017367:Selective Serotonin Reuptake Inhibitors; D000069470:Venlafaxine Hydrochloride