Clonazepam for the treatment of panic disorder

Clonazepam was initially licensed as an anti-epileptic agent, but its use in a wide variety of psychiatric conditions, including panic disorder (PD) has now been well established. This overview evaluates the current role of clonazepam alone or in combination with antidepressants and/or behavioral therapy in the treatment of PD. Information was retrieved from PubMed/MEDLINE and Excerpta medica English-literature search using the search terms ‘clonazepam’ and ‘panic disorder’ and by review of references. We review the data establishing the use of clonazepam in the treatment of PD as well as new information, particularly confirmation of long-term efficacy and safety. We also discuss a regimen for safely tapered withdrawal of clonazepam, the characteristics of the respiratory subtype of PD, and CO2-induced panic attacks as a diagnostic measure and predictor for therapeutic success. It has been shown that panic attacks can more readily be induced by CO2 in PD patients with the respiratory subtype than those with the non-respiratory subtype. More than 25 years after the first report of efficacy in PD in 1984, clonazepam, alone or combined with selective serotonin reuptake inhibitors (SSRIs) and/or behavioral therapy, remains an important therapeutic modality for the management of PD.