Before taking Herceptin, tell your doctor if you have any other medical problems, especially heart disease, lung disease, or infection.

Tell your doctor if you have ever had an allergic reaction to this or any other medication. You should not receive Herceptin if you are allergic to medicines made from Chinese hamster ovary cell protein or those containing benzyl alcohol.

Tell your doctor if you are pregnant, plan to become pregnant, or are breastfeeding. You should use birth control to prevent pregnancy during your treatment and for 6 months after your treatment. 

If you are having surgery, including dental surgery, tell the doctor or dentist that you are receiving Herceptin.