Evidences that anxiolytics has limits in the treatment of anxiety disorders (AD) are growing: maximal efficacy demonstrated in AD of simple structure and decreases when structure becomes more complex.

Evaluation of therapeutic action and effectiveness realization of different by spectral characteristics anxiolytics in AD of different structure.

To compare effectiveness of benzodiazepine derivate Phenazepam and mercaptobenzimidazole derivate Afobazol in relation to clinical picture.

This randomized comparative study of Phenazepam (2 mg/day, n = 36) and Afobazol (30 mg/day, n = 30) included patients with generalized anxiety disorder (GAD), panic disorder (PD) and nosophobia. Study included placebo lead-in and active treatment periods (14 days) and utilized HARS, ASRS Zung, Spielberger's State Anxiety Inventory and CGI scale.

Study revealed significant differences of drugs’ therapeutic action. Phenazepam promotes anxiolytic effect with hypno-sedative and muscle relaxant properties. Afobazol has selective anxiolytic action with stimulatory component. Nevertheless both drugs shared efficacy pattern.

[% of patients with high effectiveness]

Study found no differences between drugs on anxiety and effectiveness measures, though in GAD Afobazol demonstrated some advantage on efficacy due to its stimulatory action.

Study favored notion that therapeutic capabilities of anxiolytics in the AD treatment have limits regardless of drugs effects’ spectral characteristics. Effectiveness is higher in simple (GAD) and affective-loaded anxiety (linked to phobias) and lower when agoraphobia, avoidance, heteronomous sensations and overvalued hypochondriaс ideas are presented.