Tamoxifen臨床用於乳癌的治療與預防其復發已經長達30年，此藥物被廣泛應用於乳癌的輔助治療，其可以降低乳癌復發風險達40%，因乳癌而死亡的風險達三分之一。然而高達四分之一患有乳癌的婦女，在治療過程常因心情沮喪，被診斷為憂鬱症，需要藥物治療。選擇性血清素回收抑制劑具有治療憂鬱症及婦女停經症狀的效用，因此臨床上經常使用此類藥物予乳癌婦女，近日文獻探討分析發現，使用CYP2D6抑制劑的選擇性血清素回收抑制劑如克憂果(paroxetine)會降低tamoxifen的療效，使得乳癌的死亡風險增加。本文為一回顧性研究，希望經由本文探討，能讓臨床醫療人員警慎用藥以確保病人安全。

Tamoxifen has been shown over the past 30 years to be effective in the treatment of estrogen receptor(ER)-positive breast cancer. The drug is widely used in the adjuvant setting where it reduces the risk of breastcancer recurrence by almost 40% and the risk of death from breast cancer by one-third. Up to one-quarter,however, women with breast cancer suffer clinically significant depression in the year after diagnosis, whichmay respond to interventions. One class of psychotropic medications, selective serotonin reuptake inhibitors(SSRI), may reduce both depressive symptoms and menopausal symptoms. Recently, the literature analysisfound that the use of CYP2D6 inhibitor (ex: paroxetine) of selective serotonin reuptake inhibitors may reducetamoxifen efficacy and increase the risk of death from breast cancer. This article is to help clinicians be morecareful in medication use to ensure drug safety.