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Hyaluronidase / trastuzumab Side Effects

Medically reviewed by Last updated on Aug 27, 2023.

Applies to hyaluronidase / trastuzumab: subcutaneous solution.


Subcutaneous route (Solution)

Cardiomyopathy: Trastuzumab/hyaluronidase-oysk can result in subclinical and clinical cardiac failure manifesting as congestive heart failure, and decreased left ventricular ejection fraction, with greatest risk when administered concurrently with anthracyclines. Evaluate cardiac function prior to and during treatment. Discontinue trastuzumab/hyaluronidase-oysk for cardiomyopathy.Pulmonary Toxicity: Discontinue trastuzumab/hyaluronidase-oysk for anaphylaxis, angioedema, interstitial pneumonitis or acute respiratory distress syndrome.Embryo-Fetal Toxicity: Exposure to trastuzumab/hyaluronidase-oysk during pregnancy can result in oligohydramnios, in some cases complicated by pulmonary hypoplasia and neonatal death. Advise patients of these risks and the need for effective contraception.

Serious side effects

Along with its needed effects, hyaluronidase / trastuzumab 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 hyaluronidase / trastuzumab:

More common

  • Black, tarry stools
  • blurred vision
  • body aches or pain
  • chest pain or tightness
  • chills
  • cough
  • decreased urine output
  • diarrhea
  • difficulty in breathing
  • dilated neck veins
  • dizziness
  • ear congestion
  • extreme tiredness or weakness
  • fast heartbeat
  • fever
  • general feeling of discomfort or illness
  • headache
  • hives, itching, skin rash
  • hoarseness
  • irregular breathing
  • irritation
  • joint pain, stiffness, or swelling
  • loss of appetite
  • loss of voice
  • lower back or side pain
  • muscle aches and pains
  • nausea
  • nervousness
  • nosebleed
  • painful or difficult urination
  • pale skin
  • pounding in the ears
  • redness of the skin
  • runny nose or stuffy nose
  • shivering
  • slow, fast, or irregular heartbeat
  • sneezing
  • sore throat
  • sores, ulcers, or white spots on the lips or in the mouth
  • sweating
  • swelling of the eyelids, face, lips, hands, or feet
  • swollen glands
  • trouble sleeping
  • troubled swallowing
  • troubled breathing with exertion
  • unusual bleeding or bruising
  • unusual tiredness or weakness
  • vomiting
  • weight gain

Less common

  • Bladder pain
  • bloody or cloudy urine
  • difficult, burning, or painful urination
  • fainting
  • fast, pounding, or irregular heartbeat or pulse
  • frequent urge to urinate

Incidence not known

  • Bleeding gums
  • bluish color of the fingernails, lips, skin, palms, or nail beds
  • confusion
  • increased thirst
  • mood or mental changes
  • muscle cramps in the hands, arms, feet, legs, or face
  • numbness and tingling around the mouth, fingertips, or feet
  • pinpoint red spots on the skin
  • seizures
  • stomach cramps or pain
  • tremor

Other side effects

Some side effects of hyaluronidase / trastuzumab 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

  • Arm, back, or leg pain
  • belching
  • bleeding, blistering, burning, coldness, discoloration of the skin, feeling of pressure, hives, infection, inflammation, itching, lumps, numbness, pain, rash, redness, scarring, soreness, stinging, swelling, tenderness, tingling, ulceration, or warmth at the injection site
  • bone pain
  • burning, numbness, tingling, or painful sensations
  • difficulty in moving
  • discoloration of fingernails or toenails
  • feeling of warmth
  • hair loss or thinning of hair
  • heartburn
  • indigestion
  • lack or loss of strength
  • loss or change in taste
  • muscle stiffness
  • redness of the face, neck, arms and occasionally, upper chest
  • skin discoloration
  • stomach discomfort or upset
  • swelling or inflammation of the mouth
  • unsteadiness or awkwardness
  • weakness in the arms, hands, legs, or feet

Less common

  • Nasal discomfort

For Healthcare Professionals

Applies to hyaluronidase / trastuzumab: subcutaneous solution.


Very common (10% or more): Neutropenia (44%), anemia (12%), leukopenia (11%)

Common (1% to 10%): Febrile neutropenia[Ref]


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


Very common (10% or more): Infection (20%), influenza syndrome (10%)

Common (1% to 10%): Viral infection

Postmarketing reports: Immune thrombocytopenia[Ref]


Very common (10% or more): Injection site reaction/complication (e.g., joint pain, bruising, dermatitis, discoloration, discomfort, erythema, extravasation, fibrosis, hematoma, hemorrhage, hypersensitivity, induration, inflammation, irritation, macule, mass, nodule, edema, pallor, paresthesia, pruritus, rash, reaction, swelling, ulcer, vesicles, warmth) (10%)[Ref]


Very common (10% or more): Myalgia (21%), arthralgia (18%), asthenia (12%), back pain (11%), pain in extremity (10%)

Common (1% to 10%): Bone pain[Ref]


Very common (10% or more): Decreased appetite (20%)[Ref]


Very common (10% or more): Insomnia (14%)

Common (1% to 10%): Depression[Ref]


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


Common (1% to 10%): Liver function abnormal[Ref]


Postmarketing reports: Tumor lysis syndrome (TLS)


Very common (10% or more): Upper respiratory tract infection (24%), cough (22%), rhinitis (14%), pharyngitis (12%)

Common (1% to 10%): Dyspnea, epistaxis, nasal inflammation/discomfort, sinusitis[Ref]


Very common (10% or more): Fatigue (46%), chills (32%), edema (14%), pyrexia (13%)

Common (1% to 10%): Pain

Postmarketing reports: Oligohydramnios or oligohydramnios sequence (including pulmonary hypoplasia, skeletal abnormalities, and neonatal death)[Ref]

Nervous system

Very common (10% or more): Peripheral neuropathy (20%), headache (17%), dizziness (13%), dysgeusia (10%)

Common (1% to 10%): Paresthesia, peripheral neuritis, neuropathy[Ref]


Postmarketing reports: Glomerulopathy[Ref]


Very common (10% or more): Flushing (14%)

Common (1% to 10%): Hypertension, arrhythmia, ejection fraction decreased, left ventricular dysfunction, tachycardia, congestive heart failure[Ref]


Very common (10% or more): Alopecia (63%), rash (26%), nail disorder (14%)

Common (1% to 10%): Pruritus, nail discoloration, erythema, herpes simplex, acne[Ref]


Very common (10% or more): Nausea (49%), diarrhea (34%), vomiting (23%), stomatitis (21%), abdominal pain (14%), dyspepsia (11%), mucosal inflammation (10%)

Common (1% to 10%): Constipation, stomatitis[Ref]

Frequently asked questions


1. Product Information. Herceptin Hylecta (hyaluronidase-trastuzumab). Genentech. 2019.

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.