From 14 - 17, May, 2025, David Burger and Anouk Dontje went to the ESMO Breast Cancer Congress in Munich.

They presented a compelling poster titled: “Antidepressants/Anxiolytics and Breast Cancer Treatment: The Case of Drug-Drug Interactions.”

Given that patients with breast cancer experience anxiety and depression more frequently than the general population. As a result, the use of antidepressants and anxiolytics is common, raising important questions about potential drug-drug interactions (DDIs).

The analysis included 495 drug pairs, each combining a breast cancer treatment with an antidepressant or anxiolytic.

The findings were reassuring:

• 89% (443 pairs) showed no need for intervention.
• 10% (48 pairs) required additional clinical action.
• Only 1% combinations (4 pairs) were contraindicated, all involving St John’s wort.

The takeaway? While most combinations are safe, 11% of pairings may pose interaction risks.

Because of their high interaction risk, St John’s wort and nefazodone are best avoided in breast cancer treatment. For patients using ribociclib or tamoxifen, extra intervention may be needed to ensure safe and effective care.

Are you worried about potential DDIs in breast cancer treatment? Discover our free online DDI Manager on breast cancer, to alert you to potential interactions and help protect patients from adverse drug events.