The authors adjusted for non-SSRI CYP2D6 inhibiting drugs (bupropion, quinidine, thioridazine, amiodarone, cimetidine and chloroquine). In this BMJ article, other SSRI (or SNRI) antidepressant meds that were studied included fluoxetine (Prozac), sertraline (Zoloft), fluvoxamine (Luvox), citalopram (Celexa) and venlafaxine (Effexor) .

While it had no statistical association with breast cancer mortality, fluoxetine is also a potent CYP2D6 inhibitor (as is bupropion {Wellbutrin}), and sertraline is a moderate inhibitor. The study results not demonstrating statistical association of these particular SSRIs (as well as bupropion) with breast cancer mortality may well be due to small sample size and other confounding factors and should not be considered the final word about risk. Furthermore, because of the unpredictability of the distribution of genetic polymorphisms in patients being treated, at this time we suggest that you consider alternatives to SSRIs with even moderate CYP2D6 inhibition.

Attached is a list of CYP2D6 inhibitors including, but not limited to, antidepressants that you should consider when prescribing medications to patients on tamoxifen.

As more is learned about tamoxifen and SSRI drug interactions, we will attempt to inform you.

Sincerely,

Les Selbovitz, MD, Chief Medical Officer
Caroline Block, MD, Director of Medical Oncology, Auerbach Breast Center
Laurence Bailen, MD, Chair of Pharmacy and Therapeutics Committee