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Ado-trastuzumab emtansine Side Effects

For the Consumer

Applies to ado-trastuzumab emtansine: intravenous powder for solution

In addition to its needed effects, some unwanted effects may be caused by ado-trastuzumab emtansine. In the event that any of these side effects do occur, they may require medical attention.

If any of the following side effects occur while taking ado-trastuzumab emtansine, check with your doctor or nurse immediately:

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
  • chills
  • convulsions
  • cough
  • decreased urine
  • difficult or labored breathing
  • difficult, burning, or painful urination
  • dizziness
  • dry mouth
  • fever
  • frequent urge to urinate
  • headache
  • increased thirst
  • irregular heartbeat
  • loss of appetite
  • lower back or side pain
  • mood changes
  • muscle pain or cramps
  • nausea or vomiting
  • nervousness
  • nosebleeds
  • 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
  • itching

Minor Side Effects

Some of the side effects that can occur with ado-trastuzumab emtansine may not need medical attention. As your body adjusts to the medicine during treatment these side effects may go away. Your health care professional may also be able to tell you about ways to reduce or prevent some of these side effects. If any of the following side effects continue, are bothersome or if you have any questions about them, check with your health care professional:

More common:
  • Acid or sour stomach
  • belching
  • change in taste
  • constipation
  • diarrhea
  • difficulty with moving
  • heartburn
  • indigestion
  • 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

For Healthcare Professionals

Applies to ado-trastuzumab emtansine: intravenous powder for injection


The most frequently reported side effects included nausea, fatigue, musculoskeletal pain, thrombocytopenia, increased transaminases, headache, and constipation.[Ref]


Common (1% to 10%): Hypertension (5.1%), left ventricular dysfunction (1.8%)[Ref]


Very common (10% or more): Rash (11.6%)
Common (1% to 10%): Pruritus (5.5%)[Ref]


Very common (10% or more): Nausea (39.8%), constipation (26.5%), diarrhea (24.1%), vomiting (19.2%), abdominal pain (18.6%), dry mouth (16.7%), stomatitis (14.1%)
Common (1% to 10%): Dyspepsia (9.2%)[Ref]


Common (1% to 10%): Urinary tract infection (9.4%)[Ref]


Very common (10% or more): Decreased platelet count (83%), decreased hemoglobin (60%), decreased neutrophils (39%), thrombocytopenia (31.2%), anemia (14.2%)
Common (1% to 10%): Neutropenia (6.7%)[Ref]


Very common (10% or more): Increased AST (98%), increased ALT (82%), increased transaminases (28.8%), increased bilirubin (17%)
Uncommon (0.1% to 1%): Nodular regenerative hyperplasia (0.4%), portal hypertension (0.4%)[Ref]


Common (1% to 10%): Drug hypersensitivity (2.2%)[Ref]


Common (1% to 10%): Positive test for anti-ado-trastuzumab emtansine antibodies (5.3%)[Ref]


Very common (10% or more): Decreased potassium (33%), hypokalemia (10.2%)
Common (1% to 10%): Alkaline phosphatase increased (4.7%)[Ref]


Very common (10% or more): Musculoskeletal pain (36.1%), arthralgia (19.2%), myalgia (14.1%)[Ref]

Nervous system

Very common (10% or more): Headache (28.2%), peripheral neuropathy (21.2%), dizziness (10.2%)
Common (1% to 10%): Dysgeusia (8.0%)[Ref]


Common (1% to 10%): Vision blurred (4.5%), dry eye (3.9%), conjunctivitis (3.9%), lacrimation increased (3.3%)[Ref]


Very common (10% or more): Fatigue (36.3%), pyrexia (18.6%), asthenia (17.8%)
Common (1% to 10%): Chills (7.6%), peripheral edema (7.1%), infusion related reaction (1.4%)[Ref]


Very common (10% or more): Insomnia (12.0%)[Ref]


Very common (10% or more): Epistaxis (22.5%), cough (18.2%), dyspnea (12.0%),
Common (1% to 10%): Pneumonitis (1.2%)[Ref]


1. "Product Information. Kadcyla (ado-trastuzumab)." Genentech, South San Francisco, CA.

Not all side effects for ado-trastuzumab emtansine may be reported. You should always consult a doctor or healthcare professional for medical advice. Side effects can be reported to the FDA here.

Disclaimer: Every effort has been made to ensure that the information provided is accurate, up-to-date and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This material does not endorse drugs, diagnose patients, or recommend therapy. This information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill , knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate safety, effectiveness, or appropriateness for any given patient. does not assume any responsibility for any aspect of healthcare administered with the aid of materials provided. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the substances you are taking, check with your doctor, nurse, or pharmacist.