Efficacy, tolerability, and preference of mirtazapine orally disintegrating tablets in depressed patients: a 17-week naturalistic study in Lithuania

Mirtazapine is an established antidepressant with well-documented efficacy demonstrated in controlled clinical trials. However, the gap between the results obtained in controlled clinical trials and everyday clinical practice exists. Therefore, the importance of naturalistic studies in psychiatry is becoming recognized. The aim of present naturalistic study was to acquire data on efficacy, safety, and preference of mirtazapine orally disintegrating tablets during a 17-week treatment of depression. This prospective, open-label, multicenter study in patients with mild to severe depression was conducted at 47 mental health centers of Lithuania by 78 psychiatrists. Patients were initially given 15 mg or 30 mg of mirtazapine orally disintegrating tablets; the maximum allowed dose was 45 mg per day. The primary efficacy measure was the total score on the Hamilton Depression Rating Scale-17 (HAMD-17), the Clinical Global Impression-Severity (CGI-S), and Clinical Global Impression-Improvement (CGI-I) scales. Tolerability was primarily measured by assessing the incidence of treatment-emergent adverse events. Patients were evaluated at baseline, at weeks 1, 5, 9, 13, and 17. A total of 779 patients (595 women [76.4%] with a mean [SD] age of 50.2 [13.65] and 184 men [23.6%] with a mean [SD] age of 52.4 [14.6] years) were enrolled into the study; 687 (88.2%) patients completed the study. The mean (SD) daily dose of mirtazapine orally disintegrating tablets was 29.0 (3.8) mg. The mean total (SD) HAMD-17 score improved significantly from 25.7 (4.6) to 7.3 (4.3) (P<0.005). At each visit, the mean HAMD-17 score was significantly lower than that at the preceding visit. At week 17, remission (HAMD-17 score < or =7) was observed in 436 (56%) patients. The mean (SD) CGI-S score improved significantly from 4.9 (1.0) at baseline to 1.5 (0.6) at endpoint (P<0.001). According to the CGI-I assessments, 621 patients (89.4%) improved and improved very much. The vast majority of patients (80%) preferred the new formulation of mirtazapine – mirtazapine orally disintegrating tablet. Treatment-emergent adverse events occurred in 106 patients (13.6%). The most frequent adverse events were weight gain, sedation, dizziness, and dry mouth. In this study conducted in Lithuania with depressed patients, a significant improvement was shown in all efficacy measures. In addition, mirtazapine orally disintegrating tablet was a well-tolerated and preferable formulation for the treatment of depressed patients.