A Case of Serotonin Syndrome Induced by Fluoxetine and Duloxetine Independently in a Same Patient / 대한정신약물학회지

ABSTRACT

Here we report a case of serotonin syndrome caused by fluoxetine 20 mg and duloxetine 60 mg independently eight week apart. A 65-year old man developed fever, agitation and change of mental status after two weeks treatment with 20 mg of fluoxetine for depressive disorder. He was diagnosed unknown fever origin and discharged when fever subsided as antidepressant stopped. Eight weeks later he was prescribed 60 mg of duloxetine for the treatment of depressed mood. After 18 days on duloxetine he developed fever, agitation, myoclonus and change in mental status again. He improved rapidly after discontinuation of offending drug with supportive care. Despite serotonin syndrome is usually caused by poly-pharmacy of serotonergic drugs, this case shows unusual serotonin syndrome developed by therapeutic dose of two drugs of different classes independently.