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Ado-trastuzumab emtansine Side Effects

For the Consumer

Applies to ado-trastuzumab emtansine: intravenous powder for solution

Along with its needed effects, ado-trastuzumab emtansine 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 while taking ado-trastuzumab emtansine:

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

Some side effects of ado-trastuzumab emtansine 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
  • 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.

Some side effects of ado-trastuzumab emtansine may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA.

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.