Effectiveness and tolerability of eight-week treatment with dosulepin hydrochloride in patients with major depressive disorder not responding to four consecutive weeks of treatment with single selective serotonin reuptake inhibitor

Background : Though manageable, major depressive disorder remains an underdiagnosed and undertreated condition. The objective of this study was to assess the effectiveness and safety of 8 weeks of treatment with the tricyclic antidepressant dosulepin hydrochloride in patients with depressive episodes not responsive to 4 consecutive weeks of treatment with a single selective serotonin reuptake inhibitor (SSRI). Methods : Patients diagnosed with depressive episode without psychotic symptoms (by ICD-10 diagnostic criteria for research), mini-mental state examination score of ≥24, and not responsive to four weeks of treatment with SSRIs (<50% reduction in depressive symptoms) were enrolled. The main outcome measures were mean change in the Hamilton depression, Hamilton anxiety, and insomnia severity index scores at Week 8 compared to baseline. Adverse events were recorded for safety assessment. Results : A total of 94 patients were enrolled, of which, 90 (95.7%) patients completed the study. Compared to baseline, 8 weeks of treatment significantly changed the HAM-D score by -12.7 (p<0.0001), HAM-A score by -8.3 (p<0.0001), and ISI score by -10.5 (p<0.0001). One patient reported anemia and was withdrawn from the study. Dry mouth and insomnia followed by headache, blurred vision, and drowsiness were the most commonly reported side effects as measured with the antidepressant side-effects checklist. Most side effects were of mild intensity and were related to study medication. Conclusions: Eight weeks of treatment with dosulepin hydrochloride resulted in significant and clinically relevant improvements in depression, anxiety, and insomnia symptoms in Indian patients with MDD.