Acamprosate calcium as augmentation therapy for anxiety disorders.
BACKGROUND
Glutamate is a major excitatory neurotransmitter, while γ-aminobutyric acid (GABA) is a predominant inhibitory neurotransmitter in the central nervous system. This GABA-glutamate imbalance is thought to play a role in the development of anxiety. Acamprosate calcium is thought to restore this chemical imbalance in alcohol withdrawal.


OBJECTIVE
To examine acamprosate calcium as augmentation therapy for treatment of anxiety.


METHODS
This 8-week, open-label study was designed to evaluate patients with anxiety who were stable on current medications (selective serotonin-reuptake inhibitors and serotonin-norepinephrine-reuptake inhibitors) but still symptomatic. Acamprosate was dosed at 1998 mg/day. Assessments included the Hamilton Rating Scale for Anxiety (HAM-A) and the Hospital Anxiety and Depression Scale.


RESULTS
Thirteen patients enrolled in the study and received study medication. Acamprosate reduced anxiety symptoms (mean HAM-A score reduction to 8.87 from a baseline of 20). Sixty-two percent of patients receiving acamprosate achieved remission (HAM-A score ≤ 7). Modal dose was 1998 mg/day (range 999-1998). The most commonly reported adverse events were nausea (n = 1), gastrointestinal upset (n = 1), and increased dream activity (n = 1).


CONCLUSIONS
Acamprosate calcium may be effective augmentation therapy in patients with treatment-resistant anxiety.