Am J Psychiatry 1994; 151:1760-1766
Copyright © 1994 by American Psychiatric Association
Alprazolam withdrawal in patients with panic disorder and generalized anxiety disorder: vulnerability and effect of carbamazepine
E Klein, V Colin, J Stolk and RH Lenox
Department of Psychiatry, Rambam Medical Center, Haifa, Israel.
OBJECTIVE: This study was designed to examine the possibility that patients
with panic disorder are especially vulnerable to alprazolam withdrawal, as
well as to evaluate the efficacy of carbamazepine as adjunctive treatment
during alprazolam discontinuation. METHOD: After a 2-month open trial of
alprazolam, 36 patients with panic disorder and 35 with generalized anxiety
disorder entered a controlled discontinuation phase. Carbamazepine or
placebo was added in a randomized, double-blind fashion, followed after 1
week by single-blind dose reduction of alprazolam, approximately 25% every
third day. RESULTS: Fifty-two percent of the patients were able to
discontinue alprazolam, but only 37% completed the study, maintaining
alprazolam- free status for 4 weeks. Survival analysis revealed that among
the patients receiving placebo as adjunctive therapy, panic disorder
patients had a significantly greater dropout rate than patients with
generalized anxiety disorder. While carbamazepine exerted no beneficial
effect for patients with generalized anxiety disorder, it appeared to
improve outcome in the panic disorder group. CONCLUSIONS: Results of this
study indicate that panic disorder patients are more vulnerable to
alprazolam withdrawal than patients with generalized anxiety disorder, and
this may reflect a general diathesis of panic disorder patients to
encounter more difficulty during drug withdrawal. Carbamazepine may
selectively assist with alprazolam withdrawal in panic disorder patients.
However, these data do not support its widespread use during benzodiazepine
discontinuation, especially given its potential toxicity. In light of a
proposed greater vulnerability of panic disorder patients to withdrawal,
future studies need to account for differential effects related to specific
diagnosis.
