Antipsychotic agents are administered for the management of schizophrenia and schizoaffective disorders. 1 Long-acting injectable antipsychotics are usually prescribed for maintenance therapy in non-compliant/non-adherent psychotic patients. 2 The negative cardiovascular complications of antipsychotic agents include sinus tachycardia, orthostatic hypotension, polymorphic ventricular tachycardia (VT), for example, torsade de pointes or (TdP), myocarditis, cardiomyopathy, and myocardial infarction (MI). 3,4 A case report in this field had accordingly revealed bradycardia and prolonged QTc interval upon using ziprasidone in a 25-year-old man. 5 Another case had further reported sinus bradycardia, chest pain, and syncope after 1.5 mg/day risperidone administration. 6 Moreover, symptomatic bradycardia and hypotension had been simultaneously detected while taking quetiapine in a 72-year-old individual with a history of heart disease. 7 Fluphenazine decanoate, as a conventional or first-generation antipsychotic (FGA) agent, is a member of the phenothiazine-derived neuroleptics, which acts principally through the antagonism of