Clozapine for pharmacologically-resistant agitation in pediatric anti-NMDAR encephalitis: Case report

Abstract

Introduction: Anti-NMDA receptor encephalitis is a severe disorder characterized by psychiatric and neurological symptoms. Although clozapine has been used off-label with some reported success in adults, there is a lack of evidence regarding its use in pediatric populations. This case report details the successful use of clozapine to manage treatment-resistant agitation in a pediatric patient with anti-NMDA receptor encephalitis. Case report: A 7-year-old girl presented to the emergency room with hypoactive catatonia. After clinical studies, she was diagnosed with probable autoimmune encephalitis and received first-line immunotherapy and antipsychotic medication with mixed results. During hospitalization, the cata­tonia was managed with lorazepam; nevertheless, partial improvement was evidenced as psychotic symptoms and hyperexcited catatonia emerged. Agitation control did not respond to lorazepam, diazepam, or olanzapine at the maximum dose. Behavioral control was achieved only with clozapine administration, with clinically evident improvements from day one. After two weeks, clozapine was switched to olanzapine, which was well-tolerated and resulted in a favorable clinical response, lea­ding to the patient’s discharge. Conclusion: Clozapine may be a viable treatment option for anti-NMDA receptor encephalitis in the pediatric population, particularly in cases of inadequate response to standard treatment. Nonethe­less, questions remain regarding treatment protocols to minimize the risk of adverse effects and improve long-term outcomes.