Tucatinib can cause severe diarrhea including dehydration, hypotension, acute kidney injury, and death.
If diarrhea occurs, administer antidiarrheal treatment as clinically indicated. Perform diagnostic tests as clinically indicated to exclude other causes of diarrhea. Based on the severity of the diarrhea, interrupt dose, then dose reduce or permanently discontinue Tucatinib.
Tucatinib can cause severe hepatotoxicity.
Monitor ALT, AST, and bilirubin prior to starting Tucatinib, every 3 weeks during treatment, and as clinically indicated. Based on the severity of hepatotoxicity, interrupt dose, then dose reduce or permanently discontinue Tucatinib.
Advise females of reproductive potential to use effective contraception during treatment with Tucatinib and for 1 week after the last dose. Advise male patients with female partners of reproductive potential to use effective contraception during treatment with Tucatinib and for 1 week after the last dose.
from FDA,2023.01