Olanzapine-Induced Diabetic Ketoacidosis and Neuroleptic Malignant Syndrome: A Case Report

With the growing use of second-generation antipsychotics, it is important to consider rare but serious side effects. One such complication is diabetic ketoacidosis (DKA), representing a severe form of metabolic derangement. Moreover, neuroleptic malignant syndrome (NMS) is a rare but potentially fatal idiosyncratic reaction linked to this category of medications. We report the case of a 69-year-old male, not diabetic, who developed both DKA and NMS, with olanzapine identified as a probable culprit. He was on a steady dose of olanzapine for three months. He had significant biochemical and clinical improvement following prompt discontinuation of medication and supportive care. DKA improved within 24 hours, and NMS improved within one week. To our knowledge, this remains a very rarely reported occurrence of olanzapine-induced coexisting DKA and NMS. Early detection and treatment of such cases, particularly in patients exposed to antipsychotics, is crucial.