Carbamazepine treatment in patients discontinuing long-term benzodiazepine therapy. Effects on withdrawal severity and outcome.

Forty patients with a history of difficulty discontinuing long-term, daily benzodiazepine therapy were randomly assigned, under double-blind conditions, to treatment with carbamazepine (200 to 800 mg/d) or placebo. A gradual taper (25% per week reduction) off benzodiazepine therapy was then attempted. Five weeks after taper, significantly more patients who had received carbamazepine than placebo remained benzodiazepine free, this despite the fact that no statistically significant differences in withdrawal severity could be demonstrated. Patients receiving carbamazepine reported a larger reduction in withdrawal severity than patients receiving placebo, but only at a trend level, and only on the daily patient-rated withdrawal checklist. Eleven patients (28%) required antidepressant therapy for depression or panic when assessed at 12-weeks follow-up. The results of this pilot investigation suggest that carbamazepine might have promise as an adjunctive drug therapy for the benzodiazepine withdrawal syndrome, particularly in patients receiving benzodiazepines in daily dosages of 20 mg/d or greater of diazepam equivalents.