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Fam-trastuzumab deruxtecan Side Effects

Medically reviewed by Last updated on Nov 9, 2020.

For the Consumer

Applies to fam-trastuzumab deruxtecan: parenteral powder for injection


    Interstitial Lung Disease (ILD)
  • Serious, sometimes fatal, ILD, including pneumonitis, reported.1

  • Monitor for new or worsening respiratory symptoms indicative of ILD (e.g., dyspnea, cough, fever).1

  • If ILD occurs, temporary interruption, dosage reduction, or permanent discontinuance of therapy may be necessary.1 (See Dosage Modification for Toxicity under Dosage and Administration and also see ILD under Cautions.)

    Embryofetal Toxicity
  • Risk of embryofetal death or birth defects.1

  • Inform patients of risk to the fetus.1

  • Advise women of childbearing potential to use effective contraception during therapy and for at least 7 months after the last dose.1 Advise men who are partners of such women to use effective contraception during therapy and for at least 4 months after the last dose.1 (See Fetal/Neonatal Morbidity and Mortality under Cautions.)

Side effects include:

Nausea, fatigue, vomiting, alopecia, constipation, decreased appetite, anemia, neutropenia, diarrhea, leukopenia, cough, thrombocytopenia.

For Healthcare Professionals

Applies to fam-trastuzumab deruxtecan: intravenous powder for injection


Very common (10% or more): Anemia (e.g., anemia, hemoglobin decreased, hematocrit decreased, red blood cell count decreased) (31%), neutropenia (e.g., neutropenia, neutrophil count decreased) (30%), leukopenia (e.g., leukopenia, lymphopenia, white blood cell count decreased) (22%), thrombocytopenia (e.g., thrombocytopenia, platelet count decreased) (20%)[Ref]


Frequency not reported: As with all therapeutic proteins there is potential for immunogenicity[Ref]


Very common (10% or more): Dry eye (11%)[Ref]


Very common (10% or more): Decreased appetite (32%), hypokalemia (12%)[Ref]


Very common (10% or more): Aspartate aminotransferase increased (14%), alanine aminotransferase increased (14%)[Ref]


Very common (10% or more): Cough (20%), dyspnea (13%), epistaxis (13%)

Common (1% to 10%): Interstitial lung disease (ILD) (e.g., pneumonitis, ILD, respiratory failure, organizing pneumonia, acute respiratory failure, lung infiltration, lymphangitis, alveolitis), upper respiratory tract infection (e.g., influenza, influenza like illness, upper respiratory tract infection) (15%)[Ref]


Very common (10% or more): Fatigue/asthenia (59%)[Ref]

Nervous system

Very common (10% or more): Headache (e.g., headache, sinus headache, migraine) (19%)[Ref]


Frequency not reported: Left ventricular dysfunction (LVEF)[Ref]


Very common (10% or more): Alopecia (46%), rash (e.g., rash, rash pustular, rash maculopapular) (10%)[Ref]


Very common (10% or more): Nausea (79%), vomiting (47%), constipation (35%), diarrhea (29%), abdominal pain (e.g., abdominal discomfort, GI pain, abdominal pain, abdominal pain lower, abdominal pain upper) (19%), stomatitis (e.g., stomatitis, aphthous ulcer, mouth ulceration, oral mucosa erosion, oral mucosa blistering) (14%), dyspepsia (12%)[Ref]


1. "Product Information. Enhertu (fam-trastuzumab deruxtecan)." Daiichi Sankyo, Inc., Parsippany, NJ.

Frequently asked questions

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.