Dissociative side effects of repeated intranasal esketamine in a patient with preexisting dissociative symptoms

Abstract

IntroductionPatients with treatment resistant depression (TRD) who are treated with intranasal esketamine may commonly experience dissociative side effects (DSE). It is yet unknown if the same observation can be made with patients that innately manifest dissociative symptoms (DS) due to the underlying diagnosis. MethodsA 27-year-old female patient was treated for TRD and post-traumatic stress disorder (PTSD). The patient also manifested DS. Oral medication included Citalopram, Mirtazapine, Pregabalin, Opipramol, Lamotrigine, Lorazepam. After providing informed consent to participate in a clinical trial evaluating the efficacy and safety of intranasal esketamine she received 75–100 mg esketamine nasal infusions twice per week for 4 weeks (Feb. 2020-March 2020). A series of inventories were administered 60 min prior to and 40, 120 and 240 min after the infusions, during the infusion series, evaluating antidepressant (MADRS), antisuicidal effects (SSI) as well as dissociative side effects (CADSS). ResultsOur patient showed a decrease in depressive symptoms (MADRS) and suicidal ideation (SSI total score), mainly immediately post infusion. Dissociative side effects were manifested immediately after ketamine infusion. Consistently with previous studies these effects diminished with repeated dosing. LimitationsThis is an observation on a singular case with an open label study design. The dosage increase was not blinded, so that a placebo effect (in MADRS decline) can be suspected. Slight time interval differences could not be avoided. DiscussionWhile rapidly alleviating depressive and suicidal symptoms, intranasal esketamine therapy does not seem to worsen DS in patients with comorbid TRD and PTSD with DS. This is of great clinical relevance as DS do not seem to be a contraindication for esketamine therapy.