Trastuzumab deruxtecan is used to treat cancers of the breast, lung and stomach. Learn how the medication is given, its common side effects, special precautions to watch out for, and more.

What is this medication for?

Trastuzumab deruxtecan is used to treat cancers of the breast, lung and stomach.

It is made up of an anti-HER2 antibody (trastuzumab) and a chemotherapy drug (deruxtecan) linked together. The antibody helps deliver the chemotherapy drug more specifically to cancer cells to cause DNA damage and cell death. 

How should I take or use this medication?

Trastuzumab deruxtecan is injected into the vein (given intravenously) as an infusion (drip).

What precautions should I take when taking or using this medication?

Inform your healthcare professional if: 

• You are allergic to this medication or any of the other ingredients of this medication.
• You are pregnant, planning to become pregnant, or breastfeeding
  • Female patients who may become pregnant should use effective birth control during treatment and for 7 months after your last treatment
  • Male patients with female partners of reproductive potential should use effective contraception during treatment and for 4 months after the last dose of treatment.
  • Do not breastfeed during treatment and for 7 months after last dose.
• You are taking any other medications, including supplements, traditional medications and herbal remedies. 

What are some common side effects of this medication?

• Decreased white blood cells, red blood cells and platelets. This may put you at increased risk of infections, bleeding or bruising, and feeling tired. 
  • To reduce your risk of infection:
    • Practice good personal hygiene.
    • Avoid eating raw or half-cooked food.
    • Avoid crowded places and coming into close contact with people who are not feeling well. Wear a face mask when you’re going out.
  • To reduce your risk of bleeding:
    • Be careful when using sharp objects such as knives.
    • Brush your teeth with a soft-bristled toothbrush.
• Diarrhea or constipation
  • To manage diarrhea:
    • Drink more water or clear fluids to replace the fluids lost.
    • Avoid oily, spicy food or dairy products.
  • To manage constipation:
    • Drink more water or clear fluids (if you do not have a limit on the amount of water you can drink each day).
    • Add more fibre to your diet by eating more fruits and vegetable.
• Nausea or vomiting
  • Take small frequent meals. 
  • Avoid food/smells that may make you feel nauseous such as oily, fried food or strong-smelling food.
  • You may be given anti-vomiting medications. Please take as instructed.
• Mouth ulcers 
  • Avoid eating hard or spicy foods.
  • Brush teeth with a soft-bristled toothbrush.
  • Use a non-alcohol-containing mouthwash to maintain mouth hygiene after meals.
• Hair loss
  • This is a temporary side effect that may be more obvious a few weeks after treatment.
  • Use a mild shampoo (such as baby shampoo) to wash your hair and scalp.

What are some rare but serious side-effects that I need to seek medical advice immediately?

• Infusion reaction, which is an allergic reaction that happens during the infusion. Symptoms include one or more of the following:
  • Fever, chills or shivering
  • Difficulty breathing
  • Fast heartbeat
  • Itchy rashes
  • Swollen face/eyes/lips/tongue 
• Symptoms of infection such as high fever of 38 ⁰C and above
• Unusual bleeding, bruising or black sticky stools
• Symptoms of lung inflammation such as a dry cough that doesn’t go away and feeling more breathless than usual
• Symptoms of heart problems such as swelling of the lower legs, unusual weight gain and feeling breathless more easily

If you experience any of these symptoms, you should see your healthcare professional immediately.

What food or medication should I avoid when I take or use this medication?

Avoid taking traditional Chinese medications (TCM) or “jamu” when you are on this medication.

What else should I know about this medication?

This medication is also known as "fam-trastuzumab deruxtecan-nxki" or "T-DXd".

Disclaimer

Please take note that the above is not a complete list of all possible side effects. If you have any concerns about your medication or if you have other side effects that you think are caused by this medication, please consult your doctor or pharmacist.

If you take more than the recommended dose, please seek medical advice immediately. The information provided on this page does not replace information from your healthcare professional. Please consult your healthcare professional for more information.

This article is jointly developed by members of the National Medication Information workgroup. The workgroup consists of cluster partners (National Healthcare Group, National University Health System and SingHealth), community pharmacies (Guardian, Unity and Watsons) and Pharmaceutical Society of Singapore. The content does not reflect drug availability and supply information in pharmacies and healthcare institutions. You are advised to check with the respective institutions for such information.

Last updated on October 2023