What are some common side effects of herceptin (trastuzumab)?

Flu-like: Most people do pretty well with herceptin, (trastuzumab) especially after the first few doses. Flu-like symptoms are common and you may have issues with your blood counts. Your oncologist will monitor these. Uncommonly, Herceptin (trastuzumab) can lead to diminished heart function or irregular heart beats. Your oncologist will check your heart before treatment and continue to monitor.

Infusion issues: Can cause allergic reactions, infusion issues, can damage the heart, can cause scar of the lung - depresses the immune system. Fever and chills nausea vomiting pain (in some cases at tumor sites) headache dizziness shortness of breath very low blood pressure rash lack of energy and strength.