Class Name(s):

• 10:00 Antineoplastic Agents

Pronunciation:

• (pan i toom' ue mab)

Brand Name(s):

• Vectibix^®

IMPORTANT WARNING:

Panitumumab injection may cause serious or life-threatening skin reactions. Tell your doctor if you have any skin problems. If you experience any of the following symptoms, call your doctor immediately: pimples; new or worsening rash; itching or redness of the skin; blisters, peeling, dry, or cracked skin; painful sores or ulcers on your skin, lips, or in your mouth; or redness or swelling around the fingernails or toenails.

Keep all appointments with your doctor and the laboratory. Your doctor will order certain tests to check your body's response to panitumumab injection.

Talk to your doctor about the risks of receiving panitumumab injection.

WHY is this medicine prescribed?

Panitumumab injection is used to treat certain types of colon or rectal (cancer that begins in the large intestine). Panitumumab is in a class of medications called monoclonal antibodies. It works by slowing or stopping the growth of cancer cells.

HOW should this medicine be used?

Panitumumab comes as a solution (liquid) to be given by slowly injected intravenously (into a vein). It is given by a doctor or nurse in a medical office once every 2 weeks. The length of your treatment depends on how your body responds to the medication and the side effects that you experience.

Panitumumab injection may cause severe or life-threatening reactions while you receive the medication. If you experience any of the following symptoms, tell your doctor immediately: difficulty breathing or swallowing, shortness of breath, hoarseness, chest tightness, fever, chills, dizziness, or fainting.

Your doctor may need to slow down your infusion, lower your dose, or delay or stop your treatment if you experience certain side effects. Talk to your doctor about how you are feeling during your treatment.

Are there OTHER USES for this medication?

This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.

What SPECIAL PRECAUTIONS should I follow?

Before receiving panitumumab injection,

• tell your doctor or pharmacist if you are allergic to this drug, any part of this drug, or any other drugs, foods or substances. Tell your doctor or pharmacist about the allergy and what symptoms you had.
• tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take while receiving panitumumab injection. Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
• tell your doctor if you have or have ever had low levels of magnesium or calcium in your blood; lung or breathing problems; or kidney problems.
• tell your doctor if you are pregnant or plan to become pregnant. You should not become pregnant while you are receiving panitumumab injection. Use effective birth control during your treatment with panitumumab injection and for 2 months after your last dose. If you become pregnant while receiving panitumumab injection, call your doctor. Panitumumab injection may harm the fetus.
• tell your doctor if you are breast-feeding. You should not breastfeed during your treatment with panitumumab injection and for 2 months after your last dose.
• you should know that this medication may decrease fertility in women. Talk to your doctor about the risks of receiving panitumumab injection.
• plan to avoid unnecessary or prolonged exposure to sunlight and to wear protective clothing, a hat, sunglasses, and sunscreen. Panitumumab injection may make your skin sensitive to sunlight.

What SPECIAL DIETARY instructions should I follow?

Unless your doctor tells you otherwise, continue your normal diet.

What should I do IF I FORGET to take a dose?

If you miss an appointment to receive a dose of panitumumab, call your doctor right away.

What SIDE EFFECTS can this medicine cause?

Panitumumab may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• unusual tiredness or weakness
• abdominal pain
• nausea
• vomiting
• constipation
• sores in or around the mouth or lips
• muscle, joint, back, or bone pain
• growth of eyelashes

Some side effects can be serious. If you experience any of these symptoms or those listed in the IMPORTANT WARNING section, call your doctor immediately:

• new or worsening cough, shortness of breath, or chest pain
• unusual bruising or bleeding
• muscle cramps
• sudden tightening of the muscles of the hands or feet
• muscle cramps and twitching that you cannot control
• eye pain or sensitivity to light; red, swollen, or teary eyes; or other vision problems
• diarrhea
• dry mouth or skin, feeling thirsty, tiredness, dizziness, fainting, or decreased urination or dark yellow urine

Panitumumab may cause other side effects. Call your doctor if you have any unusual problems while using this medication.

What should I do in case of OVERDOSE?

In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at http://www.poisonhelp.org/help. If the victim has collapsed, had a seizure, has trouble breathing, or can't be awakened, immediately call emergency services at 911.

Symptoms of overdose may include:

• new or worsening rash; itching or redness of the skin; blisters, peeling, dry, or cracked skin; painful sores or ulcers on your skin, lips, or in your mouth; or redness or swelling around the fingernails or toenails
• unusual tiredness or weakness
• diarrhea
• dry mouth or skin, feeling thirsty, tiredness, dizziness, fainting, or decreased urination or dark yellow urine

What OTHER INFORMATION should I know?

Ask your doctor if you have any questions about your treatment with panitumumab injection.

Keep a written list of all of the prescription and nonprescription (over-the-counter) medicines, vitamins, minerals, and dietary supplements you are taking. Bring this list with you each time you visit a doctor or if you are admitted to the hospital. You should carry the list with you in case of emergencies.

This report on medications is for your information only, and is not considered individual patient advice. Because of the changing nature of drug information, please consult your physician or pharmacist about specific clinical use.

The American Society of Health-System Pharmacists, Inc. represents that the information provided hereunder was formulated with a reasonable standard of care, and in conformity with professional standards in the field. The American Society of Health-System Pharmacists, Inc. makes no representations or warranties, express or implied, including, but not limited to, any implied warranty of merchantability and/or fitness for a particular purpose, with respect to such information and specifically disclaims all such warranties. Users are advised that decisions regarding drug therapy are complex medical decisions requiring the independent, informed decision of an appropriate health care professional, and the information is provided for informational purposes only. The entire monograph for a drug should be reviewed for a thorough understanding of the drug's actions, uses and side effects. The American Society of Health-System Pharmacists, Inc. does not endorse or recommend the use of any drug. The information is not a substitute for medical care.

AHFS^® Patient Medication Information™ Copyright, 2025. The American Society of Health-System Pharmacists^®, 4500 East-West Highway, Suite 900, Bethesda, Maryland. All Rights Reserved. Duplication for commercial use must be authorized by ASHP.

Last Reviewed: June 15, 2025.