Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes Perjeta (Pertuzumab). If you are concerned about side effects, discuss the risks and benefits of Perjeta (Pertuzumab) with your doctor.

The following side effects have been reported by at least 1% of people taking Perjeta (Pertuzumab). Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• Acne
• bone, neck, chest, or abdominal pain
• changed sense of taste
• Constipation
• cough
• decreased appetite
• Diarrhea
• dizziness
• dry, itchy skin
• hair loss
• headache
• heartburn
• hot flushes
• increased tear production
• mouth sores
• nail inflammation
• nausea
• nosebleeds
• numb or tingling sensation in the legs and feet
• trouble sleeping
• vomiting

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• diarrhea
• Fever
• flu-like symptoms (e.g., nasal congestion, cough, fever, sore throat)
• fluid in the lungs (difficulty breathing)
• fluid retention (e.g., puffiness, swelling feet, ankles, feeling bloated)
• inflammation of the nail bed where the nail and skin meet
• joint or muscle pain
• muscle weakness
• signs of Anemia (low red blood cells; e.g., dizziness, pale skin, unusual tiredness or weakness, shortness of breath)
• signs of heart failure (e.g., shortness of breath, fatigue, swelling in legs, ankles, feet)
• signs of infection (symptoms may include fever or chills, severe diarrhea, shortness of breath, prolonged dizziness, headache, stiff neck, weight loss, or listlessness)
• shortness of breath, trouble breathing

Stop taking the medication and seek immediate medical attention if any of the following occur:

• signs of a serious allergic reaction (e.g., abdominal cramps, difficulty breathing, nausea and vomiting, or swelling of the face and throat)
• signs of an infusion reaction (e.g., fever, chills, dizziness, confusion, fast or slow heartbeat, irregular heart beat)

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking Perjeta (Pertuzumab).

Each mL of preservative-free liquid concentrate for infusion contains 30 mg of Perjeta (Pertuzumab). Nonmedicinal ingredients: glacial acetic acid, L-histidine, polysorbat 20, sucrose, and water for injection.

Do not take Perjeta (Pertuzumab) if you are allergic to Perjeta (Pertuzumab) or any ingredients of the medication.

There may be an interaction between Perjeta (Pertuzumab) and any of the following:

• Belimumab

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with Perjeta (Pertuzumab). Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the Nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.

Before you begin using a medication, be sure to inform your doctor of any medical conditions or Allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use Perjeta (Pertuzumab).

Diarrhea: Perjeta (Pertuzumab) may cause severe diarrhea. Your doctor may recommend that you keep a medication available to use in the event that you develop severe diarrhea. Because diarrhea can cause dehydration, which in turn can cause other medical problems, it is important to prevent or stop the diarrhea as soon as possible.

Heart problems: Perjeta (Pertuzumab) may worsen symptoms of heart disease. It can cause the heart to become less effective at pumping the blood through your body. This may be more likely to occur if you have previously been treated with any of the medications in the family known as anthracyclines (e.g., Doxorubicin, Epirubicin).

If you have heart disease such as Angina, Congestive Heart Failure, or arrhythmia, discuss with your doctor how Perjeta (Pertuzumab) may affect the medical condition, how the medical condition may affect the dosing and effectiveness of Perjeta (Pertuzumab), and whether any special monitoring is needed. Contact your doctor as soon as possible if you develop symptoms of heart problems such as shortness of breath, chest pain, rapid heartbeat, or swollen ankles.

Infection: As well as killing cancer cells, Perjeta (Pertuzumab) can reduce the number of cells that fight infection in the body (white blood cells). Avoid contact with people who have contagious infections and tell your doctor if you begin to notice signs of an infection, such as fever or chills.

Infusion reactions: Perjeta (Pertuzumab) can cause a hypersensitivity or infusion reaction. Symptoms of this type of reaction generally appear during the infusion of the medication and may include flushing, chest pain, shortness of breath and a dramatic drop in blood pressure. These reactions can cause death if a health care provider is not informed immediately. If you experience any of these symptoms, or notice them happening to someone, let your nurse or doctor know immediately.

Kidney function: Perjeta (Pertuzumab) has not been studied for use by people with decreased kidney function. If you have Kidney Disease or decreased kidney function, discuss with your doctor how Perjeta (Pertuzumab) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Perjeta (Pertuzumab), and whether any special monitoring is needed.

Liver function: Perjeta (Pertuzumab) has not been studied for use by people with decreased liver function. If you have liver disease or decreased liver function, discuss with your doctor how Perjeta (Pertuzumab) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Perjeta (Pertuzumab), and whether any special monitoring is needed.

Pregnancy: Perjeta (Pertuzumab) should not be used during pregnancy unless the benefits outweigh the risks. Women who are of child-bearing age and their partners should use birth control while either partner is using Perjeta (Pertuzumab) and for 7 months after the last dose. If you become pregnant while taking Perjeta (Pertuzumab), contact your doctor immediately.

Breast-feeding: It is not known if Perjeta (Pertuzumab) passes into breast milk. If you are a breast-feeding mother and are taking Perjeta (Pertuzumab), it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Children: The safety and effectiveness of using Perjeta (Pertuzumab) have not been established for children. 

Seniors: People over the age of 65 may be more likely to experience diarrhea from Perjeta (Pertuzumab).