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

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.

세로토닌 증후군은 세로토닌 계통의 약물사용에 따른 과도한 세로토닌 활성화에 의한 부작용이다. 저자들은 SSRI인 fluoxetine과 SNRI인 duloxetine을 치료적 용량으로 세로토닌 체계에 작용하는 다른 약물과의 사용 없이 치료 허용 용량에서 사용하였을 때 각각 2주 사용 후에 세로토닌 증후군을 보인 환자의 사례를 문헌고찰과 함께 보고한다.