Long-term experience with clonazepam in patients with a primary diagnosis of panic disorder.

This study examined the use patterns and efficacy of the high potency benzodiazepine (HPB) clonazepam in panic patients who were treated and followed naturalistically in the Massachusetts General Hospital Longitudinal Study of Panic Disorder. Of 204 patients followed over a 2-year period, 46 percent were receiving clonazepam alone or in combination with an antidepressant. Treatment was not controlled at initial evaluation or during the followup period. The main variables assessed in this analysis included global severity of the panic disorder and stability of clonazepam dose. All treatment groups tended to improve over time without significant differences in outcome between groups. Clonazepam doses remained stable over time. Results of this study suggest that treatment of panic disorder with the HPB clonazepam achieved and maintained a therapeutic benefit similar to that obtained with alternative pharmacologic treatments, without the development of tolerance as manifested by dose escalation or worsening of clinical status.