Ribociclib and Tamoxifen: Drug Interaction Guide
Quick answer: This is a major interaction — avoid combining Ribociclib and Tamoxifen unless specifically directed by your doctor.
How Ribociclib interacts with Tamoxifen
Both drugs prolong the QT interval through different mechanisms, additively increasing the risk of torsades de pointes in metastatic breast cancer patients.
What you should do
Combination is not recommended; prefer an aromatase inhibitor with ribociclib in postmenopausal patients, and obtain baseline plus periodic ECG and electrolyte checks.
Key facts
Severity
Major — avoid combination
Mechanism
Both drugs prolong the QT interval through different mechanisms, additively increasing the risk of torsades de pointes i...
Action
Combination is not recommended; prefer an aromatase inhibitor with ribociclib in postmenopausal patients, and obtain bas...
Frequently asked questions
Can I take Ribociclib and Tamoxifen together?
No — this combination should generally be avoided. Combination is not recommended; prefer an aromatase inhibitor with ribociclib in postmenopausal patients, and obtain baseline plus periodic ECG and electrolyte checks.
What is the severity of this interaction?
The interaction between Ribociclib and Tamoxifen is classified as Major — avoid combination. Both drugs prolong the QT interval through different mechanisms, additively increasing the risk of torsades de pointes in metastatic breast cancer patients.
What should I do if I'm prescribed both?
Combination is not recommended; prefer an aromatase inhibitor with ribociclib in postmenopausal patients, and obtain baseline plus periodic ECG and electrolyte checks. Always consult your prescribing clinician — do not stop or change medications without medical guidance.
Last reviewed: by iMedic Medical Editorial Team. Our editorial process.