A CONTROLLED, PROSPECTIVE, 1-YEAR TRIAL OF CITALOPRAM IN THE TREATMENT OF PANIC DISORDER

Background: The objective of this study was to evaluate the efficacy a nd tolerability of citalopram in the long-term treatment of adult outp atients with panic disorder with or without agoraphobia. Method: Patie nts in this double-blind, parallel-group trial were assigned to 1 of 3 fixed dosage ranges of citalopram (10 or 15 mg/day, 20 or 30 mg/day, or 40 or 60 mg/day), 1 dosage range of clomipramine (60 or 90 mg/day), or placebo. After the completed 8-week acute treatment period, the el igible patients could continue the treatment for up to 1 year. Of the 475 patients who were randomly assigned for the short-term trial, 279 agreed to continue double-blind treatment at their assigned doses. The primary efficacy measure used was the Clinical Anxiety Scale panic at tack item, and the response was defined as no panic attacks (score of 0 or 1). The other key measures used were the Physician's Global Impro vement Scale, the Patient's Global Improvement Scale, and the Hamilton Rating Scale for Anxiety (HAM-A). Results: In all drug-treated groups , except the group receiving the lowest citalopram dose, the treatment outcome was generally better than with placebo. As determined by a li fe table analysis of response, the probability of response during the 12 months was significantly greater with all treatment regimens than w ith placebo (p <.05), with citalopram 20 or 30 mg/day demonstrating th e best response. Panic attacks tended to disappear in all patients rem aining in the study until the end of follow-up. Analysis of the differ ence in the number of patients in different treatment groups remaining in the study (perhaps the best measure of long-term efficacy) also de monstrated that the patients treated with citalopram in dosage ranges of 20 or 30 mg/day and 40 or 60 mg/day had better response than placeb o-treated patients (p <.0002 and p <.004, respectively). HAM-A and Glo bal Improvement Scale scores also showed that patients treated with ac tive drug showed greater improvement than placebo-treated patients. Al l treatment groups showed no new or exceptional adverse event clusters . Conclusion: Citalopram in the dosage range of 20 to 60 mg/day is eff ective, well tolerated, and safe in the long-term treatment of patient s who have panic disorder.