Acute Dystonia with Paroxetine – Case Presentation, Possible Mechanism and Clinical Implications

Abstract

: Paroxetine is a selective serotonin reuptake inhibitor (SSRI) that is used in the treatment of panic disorder. SSRIs as a group are known to causeextra-pyramidal syndrome (EPS) even at therapeutic doses. However, systematic data regarding this is lacking. We describe a case of acute cervical dystonia in a young adult with panic disorder temporally related to paroxetine. The dystonia was relieved by intravenous injection of promethazine, an antihistaminic with anticholinergic property. Inhibitory serotonergic input to dopaminergic system in the nigro-striatal pathway may be responsible for such idiosyncratic reaction. Clinicians should be aware of such side effect while prescribing SSRIs as this can have significant clinical implications