Analytically Confirmed Intentional Overdose of the Antidepressant Vortioxetine

IntroductionVortioxetine is an antidepressant with a multimodal mechanism of action. It is used as a treatment option for patients with major depressive episodes. There have only been two previously reported non-fatal overdoses of vortioxetine; neither of these were analytically confirmed There has also been one case of serotonin syndrome potentially related to vortioxetine and two deaths where vortioxetine was detected. We report here a non-fatal analytically confirmed case of vortioxetine overdose.Case reportA 32-year-old male presented to the emergency department (ED) 12-13 h after oral ingestion of 1,260 mg of vortioxetine and 350 mg of diazepam. A family member reported that he had been drowsy after the overdose, but his level of consciousness and observations (heart rate, blood pressure and temperature) were normal on review by the pre-hospital emergency services and on arrival to the ED. During a period of observation, he did not develop any features of serotonin syndrome or any other significant toxicity. Toxicological analysis of a blood sample taken in the ED detected vortioxetine (plasma concentration 457 ng/mL 10 h after ingestion) and sub-therapeutic concentrations of diazepam and pregabalin.DiscussionDespite having a plasma vortioxetine concentration nearly 15-times therapeutic vortioxetine concentrations, this patient did not develop any significant toxicity. In particular he did not develop any clinical or biochemical features of serotonin toxicity that would be expected with this class of antidepressant. Additional reporting of analytically confirmed vortioxetine overdoses will allow clinicians and licensing authorities to further understand the safety of this medication in overdose.