Linda L. Carpenter, MD; Jordan M. Schecter, MD; Audrey R. Tyrka, MD, PhD; Andrea F. Mello, MD; Marcelo F. Mello, MD; Ryan Haggarty, MA; and Lawrence H. Price, MD
Objective: Gamma-aminobutyric
acid (GABA) plays a key role in the
pathophysiology and treatment of depression and anxiety.
Tiagabine, a selective GABA reuptake inhibitor
(SGRI) that enhances normal GABA tone, was
evaluated for its efficacy and safety in the treatment of
depression comorbid with significant anxiety.
Method: In this 8-week, single-center,
open-label study, adults with DSM-IV-diagnosed
major depressive disorder and significant anxiety
(i.e., "anxious depression") received tiagabine
monotherapy, initiated at 4 mg/day and titrated for
optimum response as tolerated to a maximum dose of 20 mg/day. Symptoms, function, and
adverse events were assessed at regular intervals.
Patients were entered from April 2002 to February 2003.
Results: Nineteen patients entered the
study and 15 met criteria for intent-to-treat analyses.
Of those, 6 (40%) discontinued treatment and 9 (60%) completed the 8-week protocol.
Tiagabine significantly improved depression, as shown by
a reduction in mean ± SD Hamilton Rating Scale
for Depression scores from baseline (31.9 ± 6.1)
to endpoint (17.0 ± 12.4; p = .002). Categorical
response rate was 47% (N = 7). Tiagabine also significantly improved anxiety (Hamilton
Rating Scale for Anxiety baseline score of 22.7 ± 4.9
vs. endpoint score of 12.5 ± 8.8; p=.002). The mean±SD final daily dose was 12.8 ± 5.8 mg.
The most commonly reported adverse events were dizziness, headache, and gastrointestinal
upset/nausea.
Conclusion: These results suggest the
potential of the SGRI tiagabine in the treatment of
depression with anxiety. Large, placebo-controlled trials are needed.
J Clin Psychiatry 2006;67(1):66-71
© Copyright 2006 Physicians Postgraduate Press, Inc.