Risperidone-induced type 2 diabetes presenting with diabetic ketoacidosis

Area of Science:

• Endocrinology
• Pharmacology

Background:

• A 28-year-old male developed diabetic ketoacidosis (DKA) after starting risperidone for obsessive-compulsive disorder.
• He presented with symptoms of hyperglycemia, DKA, and an initial Glasgow Coma Scale of 10/15.

Purpose of the Study:

• To investigate the potential link between risperidone use and DKA in a patient with suspected type 2 diabetes.
• To differentiate between type 1 and type 2 diabetes in the context of drug-induced DKA.

Main Methods:

• Clinical presentation assessment, including vital signs, BMI, and presence of acanthosis nigricans.
• Laboratory investigations including urinalysis (ketonuria, glycosuria) and blood results for DKA and hyperosmolar state.
• Discontinuation of risperidone, initiation of DKA protocol (insulin, fluids, potassium), and subsequent assessment of antibody markers for beta-cell autoimmunity.

Main Results:

• The patient's DKA and hyperosmolar state resolved with standard DKA management and risperidone discontinuation.
• Negative antibody markers ruled out type 1 diabetes, supporting a diagnosis of ketosis-prone type 2 diabetes (KPD).
• Metabolic parameters normalized with lifestyle modifications, reduced insulin dosage, and introduction of metformin, leading to insulin independence within 7 weeks.

Conclusions:

• Risperidone-induced DKA can be a manifestation of KPD, even in young patients, and is not exclusive to type 1 diabetes.
• Clinical indicators such as family history of T2DM and acanthosis nigricans are crucial for suspecting KPD.
• Emergency DKA management is consistent regardless of the underlying diabetes type, with KPD often confirmed later through autoimmunity testing and insulin withdrawal response.