Promethazine and Trastuzumab interaction
Promethazine and Trastuzumab: the Trastuzumab prescribing label mentions this combination without an instruction to avoid it or change the dose.
Mentioned, no instruction to avoid. Worth knowing; rarely a reason to change anything on its own.
What the FDA labels say
From the Trastuzumab (Trazimera) label · effective 2026-04-10
Prior to resumption of trastuzumab infusion, the majority of patients who experienced a severe infusion reaction were pre-medicated with antihistamines and/or corticosteroids.
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.