ABSTRACT
Antipsychotic medications are often continued throughout the perioperative period and may have significant interactions with anesthetics. Risperidone is an atypical agent used to treat both positive and negative symptoms of psychosis while producing fewer extrapyramidal symptoms. It's mode of action is related to dopaminergic and serotonergic antagonism. However, it also possesses a potent alpha-1 adrenergic antagonistic property. Here, we report a case of a 46-year-old man with major depressive disorder, controlled with paroxetine, clonazepam and risperidone, undergoing spinal anesthesia for open reduction of femur fracture. Eight minutes after induction of anesthesia, the patient developed exaggerated hypotension, unresponsive to ephedrine and rapid intravenous fluid administration. Eventually, hypotension was corrected after using large doses of phenylephrine. When planning spinal anesthesia to a patient taking risperidone, an alpha-1 agonist, such as phenylephrine, may be useful in treating possible exaggerated hypotension.
