January 1993

Maintenance Drug Treatment for Panic DisorderII. Short- and Long-term Outcome After Drug Taper

Author Affiliations

From the Psychopharmacology Research Unit, Department of Psychiatry, University of Pennsylvania (Drs Rickels and Schweizer and Ms Weiss), and the Department of Psychiatry, Pennsylvania Hospital (Dr Zavodnick), Philadelphia.

Arch Gen Psychiatry. 1993;50(1):61-68. doi:10.1001/archpsyc.1993.01820130067010

• Forty-eight patients with panic disorder completing 8 months of maintenance treatment with alprazolam (mean dose, 5.2 mg [n=27]), imipramine hydrochloride (mean dose, 175 mg [n=11]), or placebo (mean dose, 8.0 pills [n=10]) underwent a gradual taper from medication over a 4-week period. A withdrawal syndrome was observed in almost all alprazolam-treated patients but in only a few imipramine- or placebo-treated patients. The clinical worsening of withdrawal symptoms after discontinuation tended to subside over the course of 3 medication-free weeks, but 33% of alprazolam-treated patients were unable to discontinue their medication regimen successfully. Severity of panic attacks at baseline but not daily alprazolam dose appeared as a significant independent predictor of taper difficulty. Forty-nine percent of the total study population continue to receive drug therapy: 82% alprazolam and 18% imipramine. Among patients who received alprazolam during study treatment and at follow-up, the mean daily dose was substantially reduced (6.1 vs 1.6 mg [n=14]). At follow-up, after 1 year of naturalistic treatment for panic symptoms and combining 8-month completers and study dropouts, there were no significant differences in remission (68% to 71%) or in antipanic medication intake (39% to 56%) at follow-up for the three original treatment groups. However, 8-month study completers compared with study dropouts had a significantly higher remission rate (85% vs 55%).