Trastuzumab
Say it: tras-TOO-zoo-mab · Brand names: Herceptin, Herceptin Hylecta, Ogivri, Herzuma, Ontruzant, Trazimera, Kanjinti, Hercessi
Trastuzumab is a targeted antibody medicine that blocks a protein called HER2 that helps some cancers grow.
What it is
Some cancer cells have too much of a protein called HER2, which tells them to grow fast. Trastuzumab sticks to HER2 and blocks these growth signals. It also flags the cancer cells so your immune system can attack them.
Often used for
- HER2 positive breast cancer, early or spread
- HER2 positive stomach cancer
- HER2 positive cancer where the esophagus meets the stomach
How you get it
Most people get trastuzumab as an infusion into a vein. The first infusion takes about 90 minutes, and later ones take about 30 minutes. One form is a shot under the skin that takes a few minutes. It is usually given every 3 weeks (sometimes every week), often for up to a year for early breast cancer. Your schedule may be different.
Common side effects and what helps
- Fever or chills, especially with the first infusion. Your team will watch you closely.
- Feeling tired. Rest and short walks can help.
- Nausea or diarrhea. Eat small meals and drink fluids.
- Headache. Rest and drink fluids.
- Cough or cold symptoms. Tell your team if they do not go away.
- Trouble sleeping. A calm bedtime routine can help.
- Rash. Use gentle soap and unscented lotion.
Call your care team right away if you have
- Shortness of breath, swelling in your legs or belly, fast weight gain, or a racing heartbeat
- Trouble breathing, wheezing, chest tightness, or swelling of the face during or after an infusion
- A fever of 100.4 degrees Fahrenheit (38 degrees Celsius) or higher
- New or worse cough
- Feeling very dizzy or faint
Before you start, tell your team
- If you have heart problems or high blood pressure
- If you have had chemotherapy medicines like doxorubicin before
- If you have lung problems
- If you are pregnant, may become pregnant, or are breastfeeding
- All the medicines, vitamins, and herbal products you take
Good to know
- This medicine can weaken the heart. You will have heart tests, such as an echocardiogram, before treatment and about every 3 months during it.
- Serious infusion reactions and lung problems can happen, most often with the first infusion.
- This medicine can harm an unborn baby. Use birth control during treatment and for 7 months after the last dose. If you become pregnant, tell your team right away.
Questions to ask
- How often will you check my heart?
- How long will I get this medicine?
- Will I get the infusion or the shot under the skin?
- What should I do if I feel short of breath?
Part of these treatment plans
Side effect guides
- Fatigue (tiredness)
- Nausea and vomiting
- Diarrhea
- Skin rash (including EGFR-inhibitor rash)
- Cough
- Sleep problems
Sources
Quick answers
- What is Trastuzumab?
- Trastuzumab is a targeted antibody medicine that blocks a protein called HER2 that helps some cancers grow. Brand names: Herceptin, Herceptin Hylecta, Ogivri, Herzuma, Ontruzant, Trazimera, Kanjinti, Hercessi.
- What is Trastuzumab used for?
- HER2 positive breast cancer, early or spread; HER2 positive stomach cancer; HER2 positive cancer where the esophagus meets the stomach.
- How is Trastuzumab given?
- Most people get trastuzumab as an infusion into a vein. The first infusion takes about 90 minutes, and later ones take about 30 minutes. One form is a shot under the skin that takes a few minutes. It is usually given every 3 weeks (sometimes every week), often for up to a year for early breast cancer. Your schedule may be different.
- What are the common side effects of Trastuzumab?
- Fever or chills, especially with the first infusion. Feeling tired. Nausea or diarrhea. Headache. Cough or cold symptoms. Trouble sleeping. Rash.
- When should I call my care team while taking Trastuzumab?
- Shortness of breath, swelling in your legs or belly, fast weight gain, or a racing heartbeat; Trouble breathing, wheezing, chest tightness, or swelling of the face during or after an infusion; A fever of 100.4 degrees Fahrenheit (38 degrees Celsius) or higher; New or worse cough; Feeling very dizzy or faint.
- Which chemotherapy plans include Trastuzumab?
- TCHP, THP.
Last updated: 2026-10-27. Medically reviewed by Veli Bakalov, MD, medical oncologist (October 2026). General education from Step by Step, the patient portal of HemeOncBuddy.