Clinical switching strategies of various antidepressants to Vortioxetine in the PREDDICT trial.

BACKGROUND Partial response to antidepressant medication, as well as relapse and treatment resistance are common in Major Depressive Disorder (MDD). Therefore, for most patients with MDD there will be a need to consider changing antidepressant medication at some stage during the course of the illness. The PREDDICT study investigates the efficacy of augmenting vortioxetine with celecoxib. METHODS We describe the method used in the PREDDICT study to change participants, who were already taking antidepressant medication at the time of the screening visit, to vortioxetine. We used a cross-titration to change study participants to vortioxetine. RESULTS Out of a total of 122 study participants who were randomized to receive vortioxetine plus celecoxib or vortioxetine plus placebo at the study baseline visit, 82 were taking antidepressant medication (other than vortioxetine) prior to randomization. These medications were selective serotonin reuptake inhibitors, serotonin noradrenaline reuptake inhibitors, tricyclic antidepressants, mirtazapine, or agomelatine. Eighty of these 82 participants completed the changeover to vortioxetine, as well as the study baseline visit. We found side effects were generally mild during this changeover period. In addition, there was a reduction in mean total MADRS score of 2.5 (standard deviation (SD) 6.0) from study baseline to week 2, and a further reduction in mean total MADRS of 2.5 (SD 5.9) from week 2 to week 4. CONCLUSION Changing other antidepressants to vortioxetine can be done safely, and was generally well tolerated. However, there were some antidepressant classes, in particular monoamine oxidase inhibitors which require a washout period, that were not represented in this study.