Lacosamide (LCM) has both frequent side effects, such as headache, diplopia, and nausea, and rare side effects such as depression, mood changes, and confusion. This article presents a case of possible LCM-induced psychosis and reviews the literature. A 22-year-old woman presented to the Emergency Department in Status Epilepticus. The seizure was treated with intravenous midazolam and valproic acid. However, she developed cardiopulmonary arrest and was resuscitated successfully. She was intubated and admitted to the intensive care unit. She had first been diagnosed with epilepsy 15 years earlier and had been seizure-free for 3 years. She had undergone a sleeve gastrectomy 1 year earlier. She was extubated the day after admission. LCM 200 mg/day was added to the treatment because of generalized seizures beginning in the right arm. Her seizures were controlled on the 4th hospital day. However, after starting LCM, she developed agitation, visual hallucinations with a sexual content, and intellectual delusions. Therefore, the LCM was discontinued and her psychosis resolved completely 4 days later. On the 12th hospital day, she was discharged. LCM blocks sodium channels and can act as a mood stabilizer and sedative. However, our patient developed psychosis with LCM treatment. This is the first reported case of LCM-induced psychosis in Turkey. Visual hallucinations and psychosis may develop immediately after starting LCM therapy. Clinical recovery can be achieved by discontinuing the drug.

Keywords: Lacosamide, psychosis, status epilepticus, visual hallucinations