Trastuzumab and hyaluronidase-oysk (Herceptin Hylecta™)

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About This Drug

Trastuzumab and hyaluronidase-oysk is used to treat cancer. It is given as an injection under the skin (subcutaneously).

Possible Side Effects

  • Congestive heart failure – your heart has less ability to pump blood properly
  • Nausea
  • Diarrhea (loose bowel movements)
  • Fever
  • Chills
  • Tiredness
  • Swelling of your legs, ankles and/or feet
  • Injection site reaction - you may get a rash, swelling or bruising or your skin may get red, warm, itchy or painful at the site of your infusion or injection
  • Pain in your arms and/or legs
  • Joint and/or muscle pain
  • Headache
  • Trouble sleeping
  • Cough
  • Upper respiratory infection
  • Rash
  • Hot flashes or sudden skin flushing may happen. You may also feel warm or red.

Note: Each of the side effects above was reported in 10% or greater of patients treated with trastuzumab and hyaluronidase-oysk. Not all possible side effects are included above.

Warnings and Precautions

  • Changes in the tissue of the heart and heart function, which may be life-threatening. Some changes may happen that can cause your heart to have less ability to pump blood. This drug may also increase your risk of heart attack.
  • Serious and life-threatening lung problems such as inflammation (swelling) and scarring of the lungs which makes breathing difficult.
  • While you are getting this drug, you may have a reaction to the drug, which may be life-threatening. Sometimes you may be given medication to stop or lessen these side effects. Your nurse will check you closely for these signs: fever or shaking chills, flushing, facial swelling, feeling dizzy, headache, trouble breathing, rash, itching, chest tightness, or chest pain. These reactions may happen after your infusion. If this happens, call 911 for emergency care.
  • Severe decrease in the number of white blood cells. This may raise your risk of infection which may be life-threatening.

Note: Some of the side effects above are very rare. If you have concerns and/or questions, please discuss them with your medical team.

Important Information

  • This drug may be present in the saliva, tears, sweat, urine, stool, vomit, semen, and vaginal secretions. Talk to your doctor and/or your nurse about the necessary precautions to take during this time.

Treating Side Effects

  • Manage tiredness by pacing your activities for the day.
  • Be sure to include periods of rest between energy-draining activities.
  • To decrease the risk of infection, wash your hands regularly.
  • Avoid close contact with people who have a cold, the flu, or other infections.
  • Take your temperature as your doctor or nurse tells you, and whenever you feel like you may have a fever.
  • Drink plenty of fluids (a minimum of eight glasses per day is recommended).
  • To help with nausea, eat small, frequent meals instead of three large meals a day. Choose foods and drinks that are at room temperature. Ask your nurse or doctor about other helpful tips and medicine that is available to help or stop lessen these symptoms.
  • If you throw up or have loose bowel movements, you should drink more fluids so that you do not become dehydrated (lack of water in the body from losing too much fluid).
  • If you have diarrhea, eat low-fiber foods that are high in protein and calories and avoid foods that can irritate your digestive tracts or lead to cramping.
  • Ask your nurse or doctor about medicine that can lessen or stop your diarrhea.
  • If you get a rash do not put anything on it unless your doctor or nurse says you may. Keep the area around the rash clean and dry. Ask your doctor for medicine if your rash bothers you.
  • Keeping your pain under control is important to your well-being. Please tell your doctor or nurse if you are experiencing pain.
  • If you are having trouble sleeping, talk to your nurse or doctor on tips to help you sleep better 
  • Infusion reactions may occur after your infusion. If this happens, call 911 for emergency care.
  • While you are getting this drug, please tell your nurse right away if you get a rash, swelling or bruising or your skin gets red, warm, itchy or painful at the site of your infusion or injection.

Food and Drug Interactions

  • There are no known interactions of trastuzumab and hyaluronidase-oysk with food.
  • This drug may interact with other medicines. Tell your doctor and pharmacist about all the prescription and over-the-counter medicines and dietary supplements (vitamins, minerals, herbs and others) that you are taking at this time. Also, check with your doctor or pharmacist before starting any new prescription or over-the-counter medicines, or dietary supplements to make sure that there are no interactions. Let your doctor know that you are receiving trastuzumab and hyaluronidase-oysk or have received this medication in the past.

When to Call the Doctor

Call your doctor or nurse if you have any of these symptoms and/or any new or unusual symptoms:

  • Fever of 100.4° F (38° C) or higher
  • Chills
  • Tiredness that interferes with your daily activities
  • Feeling dizzy or lightheaded
  • A headache that does not go away
  • Wheezing or trouble breathing
  • Coughing up yellow, green, or bloody mucus
  • Feeling that your heart is beating in a fast or not normal way (palpitations)
  • Chest pain or symptoms of a heart attack. Most heart attacks involve pain in the center of the chest that lasts more than a few minutes. The pain may go away and come back or it can be constant. It can feel like pressure, squeezing, fullness, or pain. Sometimes pain is felt in one or both arms, the back, neck, jaw, or stomach. If any of these symptoms last 2 minutes, call 911. 
  • Nausea that stops you from eating or drinking and/or is not relieved by prescribed medicines
  • Diarrhea, 4 times in one day or diarrhea with lack of strength or a feeling of being dizzy
  • Lasting loss of appetite or rapid weight loss of five pounds in a week
  • Swelling of legs, ankles, or feet
  • Weight gain of 5 pounds in one week (fluid retention)
  • A new rash or a rash that is not relieved by prescribed medicines
  • Signs of reaction: fever or shaking chills, flushing, facial swelling, feeling dizzy, headache, trouble breathing, rash, itching, chest tightness, or chest pain
  • Pain that does not go away, or is not relieved by prescribed medicines
  • If you think you may be pregnant

Reproduction Warnings

  • Pregnancy warning: This drug may/can have harmful effects on the unborn baby. Women of childbearing potential should use effective methods of birth control during your cancer treatment and for 7 months after treatment. Let your doctor know right away if you think you may be pregnant during treatment or within 7 months of receiving treatment.
  • Breastfeeding warning: It is not known if this drug passes into breast milk. For this reason, women should talk to their doctor about the risks and benefits of breastfeeding during treatment with this drug and for 7 months after treatment because this drug may enter the breast milk and cause harm to a breastfeeding baby.
  • Fertility warning: Human fertility studies have not been done with this drug. Talk with your doctor or nurse if you plan to have children. Ask for information on sperm or egg banking.

Revised March 2019

This patient information was developed by Via Oncology, LLC © 2018. This information is not intended to be used as a substitute for professional medical advice, diagnosis, or treatment. You should not rely entirely on this information for your health care needs. Ask your own doctor or health care provider any specific medical questions that you have.

CLIENT acknowledges that the Via Pathways and Via Portal are information management tools only, and that Via Oncology, LLC has not represented the Via Pathways or Via Portal as having the ability to diagnose disease, prescribe treatment, or perform any other tasks that constitute the practice of medicine. The clinical information contained in the Via Pathways and Via Portal are intended as a supplement to, and not a substitute for, the knowledge, expertise, skill, and judgment of physicians, pharmacists and other healthcare professionals involved with patient care at CLIENT facilities.