Tamoxifen and depression: drug interactions in breast cancer.

This case describes a 76-year-old African-American female with a history of depression, breast cancer, and hypothyroidism admitted to the inpatient geriatric psychiatry unit for an electroconvulsive therapy (ECT) evaluation. She had one previous episode of depression, which began after a lumpectomy in 2007. Her home medication regimen included tamoxifen 20 mg daily. This case highlights the incidence of depression in persons with breast cancer, examines the controversy of tamoxifen-induced depression, and evaluates antidepressant considerations regarding potentially efficacy-reducing cytochrome P450 2D6 drug interactions with tamoxifen. The pharmacy team played an active role in educating the medical team regarding tamoxifen drug interactions. After many discussions, the patient was ultimately treated with mirtazapine 15 mg at bedtime, in addition to ECT.