Efficacy and safety of venlafaxine ER vs. amitriptyline ER in patients with major depression of moderate severity.

Abstract

A double-blind, randomized phase-III study was conducted with the aim to compare the efficacy and safety of venlafaxine ER (extended release) with that of amitriptyline ER in moderately depressed outpatients. Patients with major depression of moderate severity, HAM-D (Hamilton Depression scale, 21 items) score 20-26, were given a six-week double-blind treatment with venlafaxine ER and amitriptyline ER in a dosis of 75 mg each, which could be increased to 150 mg, if necessary. Efficacy was assessed using HAM-D and CGI (clinical global impression) scores. Safety analysis was carried out using the HAM-D item 3 to assess suicidality, the d2 test to evaluate attention and drug screening for benzodiazepines. Adverse events were recorded at each visit. 160 patients were randomized. There were 151 patients available for analysis in the intent-to-treat (ITT) population. The according-to-protocol (ATP) population consisted of 117 patients, with 60 patients in the venlafaxine ER group and 57 in the amitriptyline ER (extended release) group. The non-inferiority of venlafaxine ER compared to amitriptyline ER with reference to the primary efficacy parameter, the change of HAM-D total score, could be proven in both the ITT population and the ATP population. There were no significant differences between groups in the HAM-D response rates and the CGI scores of items 1 (severity) and 2 (improvement). Venlafaxine ER showed a more favorable safety profile than amitriptyline ER: adverse drug reactions were less frequent under venlafaxine ER than under amitriptyline ER. Most of the discontinuations in the amitriptyline ER group were due to dry mouth. The d2 test showed greater improvement of performance under venlafaxine ER. In this study with patients treated for major depression of moderate severity, the non-inferiority of venlafaxine ER compared to amitriptyline ER with respect to the chosen efficacy parameter could be demonstrated. Venlafaxine ER showed a more favorable safety profile than amitriptyline ER.