Risperidone and exaggerated hypotension during a spinal anesthetic.
Antipsychotic medications are often continued through pregnancy and may have important anesthetic interactions. For example, risperidone is an antipsychotic medication with therapeutic effects mediated by dopaminergic and serotonergic antagonism. However, it also possesses potent alpha-1 adrenergic antagonism. Here we report a case of a parturient with bipolar disease, controlled with lithium and risperidone, undergoing a spinal anesthetic for a cesarean delivery. The parturient developed exaggerated hypotension, refractory to conventional treatment with ephedrine and IV fluids, that eventually responded to large doses of phenylephrine. Risperidone alpha-antagonism should be a consideration for any patient receiving this medication during neuraxial anesthesia. Treatment of significant and refractory hypotension with an alpha-1 agonist such as phenylephrine may be warranted.


CONCLUSIONS
Parturients receiving neuraxial blocks may be taking antipsychotic medications. Although the therapeutic effects of antipsychotic medications are mediated by dopaminergic and serotonergic antagonism, many possess alpha-adrenergic antagonist properties. We report a case of exaggerated hypotension during a spinal anesthetic for cesarean delivery that may have been a result of the alpha-adrenergic antagonism of risperidone.
Williams
James H
JH
From the Department of Anesthesia and Critical Care, Massachusetts General Hospital, Harvard Medical School, and the Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts.
Hepner
David L
DL
D000316:Adrenergic alpha-Agonists / Q000627:therapeutic use; D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000328:Adult; D000775:Anesthesia, Spinal / Q000009:adverse effects*; D018692:Antimanic Agents / Q000627:therapeutic use; D014150:Antipsychotic Agents / Q000009:adverse effects*; D001714:Bipolar Disorder / Q000150:complications / Q000188:drug therapy; D002585:Cesarean Section; D005260:Female; D006801:Humans; D007022:Hypotension / Q000139:chemically induced* / Q000188:drug therapy; D008094:Lithium / Q000627:therapeutic use; D010656:Phenylephrine / Q000627:therapeutic use; D011247:Pregnancy; D018967:Risperidone / Q000009:adverse effects*
D000316:Adrenergic alpha-Agonists; D000317:Adrenergic alpha-Antagonists; D018692:Antimanic Agents; D014150:Antipsychotic Agents; D010656:Phenylephrine; D008094:Lithium; D018967:Risperidone