Specialty Drug

Ado-Trastuzumab Emtansine

ADO-TRASTUZUMAB EMTANSINE is a monoclonal antibody combined with chemotherapy. It is used to treat breast cancer. Compare HER2 receptor antagonists.

Kadcyla Side Effects

What should I watch for?

Visit your doctor for checks on your progress. This drug may make you feel generally unwell. This is not uncommon, as chemotherapy can affect healthy cells as well as cancer cells. Report any side effects. Continue your course of treatment even though you feel ill unless your doctor tells you to stop.

Call your doctor or health care professional for advice if you get a fever, chills or sore throat, or other symptoms of a cold or flu. Do not treat yourself. This drug decreases your body's ability to fight infections. Try to avoid being around people who are sick.

Be careful brushing and flossing your teeth or using a toothpick because you may get an infection or bleed more easily. If you have any dental work done, tell your dentist you are receiving this medicine.

Avoid taking products that contain aspirin, acetaminophen, ibuprofen, naproxen, or ketoprofen unless instructed by your doctor. These medicines may hide a fever.

Do not become pregnant while taking this medicine or for 7 months after stopping it. Women should inform their doctor if they wish to become pregnant or think they might be pregnant. There is a potential for serious side effects to an unborn child. [Men should inform their doctors if they wish to father a child. This medicine may lower sperm counts.] Talk to your health care professional or pharmacist for more information. Do not breast-feed an infant while taking this medicine.

You may need blood work done while you are taking this medicine.


Interactions with Medications

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor or nurse immediately if any of the following side effects occur:

More common

Black, tarry stools

bladder pain

bleeding gums

bloating or swelling of the face, arms, hands, lower legs, or feet

bloody or cloudy urine

blurred vision

burning, numbness, tingling, or painful sensations




decreased urine

difficult or labored breathing

difficult, burning, or painful urination


dry mouth


frequent urge to urinate


increased thirst

irregular heartbeat

loss of appetite

lower back or side pain

mood changes

muscle pain or cramps

nausea or vomiting



numbness or tingling in the hands, feet, or lips

pale skin

pinpoint red spots on the skin

pounding in the ears

rapid weight gain

slow or fast heartbeat

sore throat

tightness in the chest

troubled breathing with exertion

ulcers, sores, or white spots in the mouth

unsteadiness or awkwardness

unusual bleeding or bruising

unusual tiredness or weakness

unusual weight gain or loss

weakness in the arms, hands, legs, or feet

Less common

Chest pain

dilated neck veins

extreme fatigue

general feeling of discomfort or illness

irregular breathing

irregular heartbeat

skin rash

thickening of bronchial secretions


Dark-colored urine

general feeling of tiredness or weakness

light-colored stools

stomach bloating or pain

vomiting blood

yellow eyes or skin

Incidence not known

Abdominal or stomach tenderness


Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

Acid or sour stomach


change in taste



difficulty with moving



lack or loss of strength

loss of taste

muscle pain or stiffness

pain in the joints

stomach discomfort or upset

swelling or inflammation of the mouth

trouble sleeping

Less common

Burning, dry, or itching eyes

discharge or excessive tearing

redness, pain, or swelling of the eye, eyelid, or inner lining of the eyelid

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

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