Unveiling the Side Effects: Extrapyramidal Symptoms Caused by Blonanserin

Schizophrenia is a chronic debilitating illness with positive and negative symptoms and cognitive impairment that significantly limits social functioning. First authorized in January 2008 for the treatment of schizophrenia in Japan, Blonanserin was also approved in Korea in August 2009 and China in February 2017. Dopamine 2 receptors, serotonin 2A receptors, and dopamine 3 receptors are all blocked by Blonanserin. This case report describes the case of a 28-year-old man hailing from Kamrup Rural district, Assam, who was diagnosed with chronic schizophrenia on regular medications for the last six years. History of previous hospital admission in 2023 for drug-induced extrapyramidal symptoms (EPS) was present after receiving a long-acting injection of Fluphenazine Decanoate 25 mg and tablet Risperidone. He was discharged with tablet Blonanserin 8 mg twice daily, and doses increased to 24 mg/day in a subsequent follow-up after discharge. The patient developed slowness of movements, stooped posture, tightening of limbs, tremors, increased salivation, reduced verbal communication, reduced oral intake, and not passing urine and stools for six days, for which he was admitted to the psychiatry ward of a tertiary care hospital in 2024 with a provisional diagnosis of chronic schizophrenia with drug-induced EPS and treated with injection Promethazine, injection Lorazepam, tablet Trihexyphenidyl, and tablet Amantadine after stopping Blonanserin. During the patient’s hospital stay, he developed akathisia, after which beta-blocker Propranolol was added. This case highlights the adverse effects of Blonanserin and emphasizes the importance of proper monitoring of the adverse effects of antipsychotic medications in every patient, especially those having a history of drug-induced EPS.