Ssris and Tamoxifen: Drug Interaction Guide
Quick answer: This is a major interaction — avoid combining Ssris and Tamoxifen unless specifically directed by your doctor.
How Ssris interacts with Tamoxifen
Strong CYP2D6 inhibitors such as paroxetine and fluoxetine reduce tamoxifen conversion to its active metabolite endoxifen by up to 60%, potentially reducing breast cancer recurrence protection.
What you should do
Prefer SSRIs with minimal CYP2D6 inhibition such as venlafaxine, escitalopram, or citalopram for hot flashes or depression in tamoxifen-treated women.
Key facts
Severity
Major — avoid combination
Mechanism
Strong CYP2D6 inhibitors such as paroxetine and fluoxetine reduce tamoxifen conversion to its active metabolite endoxife...
Action
Prefer SSRIs with minimal CYP2D6 inhibition such as venlafaxine, escitalopram, or citalopram for hot flashes or depressi...
Frequently asked questions
Can I take Ssris and Tamoxifen together?
No — this combination should generally be avoided. Prefer SSRIs with minimal CYP2D6 inhibition such as venlafaxine, escitalopram, or citalopram for hot flashes or depression in tamoxifen-treated women.
What is the severity of this interaction?
The interaction between Ssris and Tamoxifen is classified as Major — avoid combination. Strong CYP2D6 inhibitors such as paroxetine and fluoxetine reduce tamoxifen conversion to its active metabolite endoxifen by up to 60%, potentially reducing breast cancer recurrence protection.
What should I do if I'm prescribed both?
Prefer SSRIs with minimal CYP2D6 inhibition such as venlafaxine, escitalopram, or citalopram for hot flashes or depression in tamoxifen-treated women. Always consult your prescribing clinician — do not stop or change medications without medical guidance.
Last reviewed: by iMedic Medical Editorial Team. Our editorial process.